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TOPICS
Books V-VIII

by Aristotle


BOOK V

Part 1 

The question whether the attribute stated is or is not a property,
should be examined by the following methods: 

Any 'property' rendered is always either essential and permanent or
relative and temporary: e.g. it is an 'essential property' of man
to be 'by nature a civilized animal': a 'relative property' is one
like that of the soul in relation to the body, viz. that the one is
fitted to command, and the other to obey: a 'permanent property' is
one like the property which belongs to God, of being an 'immortal
living being': a 'temporary property' is one like the property which
belongs to any particular man of walking in the gymnasium.

[The rendering of a property 'relatively' gives rise either to two
problems or to four. For if he at the same time render this property
of one thing and deny it of another, only two problems arise, as in
the case of a statement that it is a property of a man, in relation
to a horse, to be a biped. For one might try both to show that a man
is not a biped, and also that a horse is a biped: in both ways the
property would be upset. If on the other hand he render one apiece
of two attributes to each of two things, and deny it in each case
of the other, there will then be four problems; as in the case of
a statement that it is a property of a man in relation to a horse
for the former to be a biped and the latter a quadruped. For then
it is possible to try to show both that a man is not naturally a biped,
and that he is a quadruped, and also that the horse both is a biped,
and is not a quadruped. If you show any of these at all, the intended
attribute is demolished.] 

An 'essential' property is one which is rendered of a thing in comparison
with everything else and distinguishes the said thing from everything
else, as does 'a mortal living being capable of receiving knowledge'
in the case of man. A 'relative' property is one which separates its
subject off not from everything else but only from a particular definite
thing, as does the property which virtue possesses, in comparison
with knowledge, viz. that the former is naturally produced in more
than one faculty, whereas the latter is produced in that of reason
alone, and in those who have a reasoning faculty. A 'permanent' property
is one which is true at every time, and never fails, like being' compounded
of soul and body', in the case of a living creature. A 'temporary'
property is one which is true at some particular time, and does not
of necessity always follow; as, of some particular man, that he walks
in the market-place. 

To render a property 'relatively' to something else means to state
the difference between them as it is found either universally and
always, or generally and in most cases: thus a difference that is
found universally and always, is one such as man possesses in comparison
with a horse, viz. being a biped: for a man is always and in every
case a biped, whereas a horse is never a biped at any time. On the
other hand, a difference that is found generally and in most cases,
is one such as the faculty of reason possesses in comparison with
that of desire and spirit, in that the former commands, while the
latter obeys: for the reasoning faculty does not always command, but
sometimes also is under command, nor is that of desire and spirit
always under command, but also on occasion assumes the command, whenever
the soul of a man is vicious. 

Of 'properties' the most 'arguable' are the essential and permanent
and the relative. For a relative property gives rise, as we said before,
to several questions: for of necessity the questions arising are either
two or four, or that arguments in regard to these are several. An
essential and a permanent property you can discuss in relation to
many things, or can observe in relation to many periods of time: if
essential', discuss it in comparison with many things: for the property
ought to belong to its subject in comparison with every single thing
that is, so that if the subject be not distinguished by it in comparison
with everything else, the property could not have been rendered correctly.
So a permanent property you should observe in relation to many periods
of time; for if it does not or did not, or is not going to, belong,
it will not be a property. On the other hand, about a temporary property
we do not inquire further than in regard to the time called 'the present';
and so arguments in regard to it are not many; whereas an arguable'
question is one in regard to which it is possible for arguments both
numerous and good to arise. 

The so-called 'relative' property, then, should be examined by means
of the commonplace arguments relating to Accident, to see whether
it belongs to the one thing and not to the other: on the other hand,
permanent and essential properties should be considered by the following
methods. 


Part 2

First, see whether the property has or has not been rendered correctly.
Of a rendering being incorrect or correct, one test is to see whether
the terms in which the property is stated are not or are more intelligible-for
destructive purposes, whether they are not so, and for constructive
purposes, whether they are so. Of the terms not being more intelligible,
one test is to see whether the property which he renders is altogether
more unintelligible than the subject whose property he has stated:
for, if so, the property will not have been stated correctly. For
the object of getting a property constituted is to be intelligible:
the terms therefore in which it is rendered should be more intelligible:
for in that case it will be possible to conceive it more adequately,
e.g. any one who has stated that it is a property of 'fire' to 'bear
a very close resemblance to the soul', uses the term 'soul', which
is less intelligible than 'fire'-for we know better what fire is than
what soul is-, and therefore a 'very close resemblance to the soul'
could not be correctly stated to be a property of fire. Another test
is to see whether the attribution of A (property) to B (subject) fails
to be more intelligible. For not only should the property be more
intelligible than its subject, but also it should be something whose
attribution to the particular subject is a more intelligible attribution.
For he who does not know whether it is an attribute of the particular
subject at all, will not know either whether it belongs to it alone,
so that whichever of these results happens, its character as a property
becomes obscure. Thus (e.g.) a man who has stated that it is a property
of fire to be 'the primary element wherein the soul is naturally found',
has introduced a subject which is less intelligible than 'fire', viz.
whether the soul is found in it, and whether it is found there primarily;
and therefore to be 'the primary element in which the soul is naturally
found' could not be correctly stated to be a property of 'fire'. On
the other hand, for constructive purposes, see whether the terms in
which the property is stated are more intelligible, and if they are
more intelligible in each of the aforesaid ways. For then the property
will have been correctly stated in this respect: for of constructive
arguments, showing the correctness of a rendering, some will show
the correctness merely in this respect, while others will show it
without qualification. Thus (e.g.) a man who has said that the 'possession
of sensation' is a property of 'animal' has both used more intelligible
terms and has rendered the property more intelligible in each of the
aforesaid senses; so that to 'possess sensation' would in this respect
have been correctly rendered as a property of 'animal'. 

Next, for destructive purposes, see whether any of the terms rendered
in the property is used in more than one sense, or whether the whole
expression too signifies more than one thing. For then the property
will not have been correctly stated. Thus (e.g.) seeing that to 'being
natural sentient' signifies more than one thing, viz. (1) to possess
sensation, (2) to use one's sensation, being naturally sentient' could
not be a correct statement of a property of 'animal'. The reason why
the term you use, or the whole expression signifying the property,
should not bear more than one meaning is this, that an expression
bearing more than one meaning makes the object described obscure,
because the man who is about to attempt an argument is in doubt which
of the various senses the expression bears: and this will not do,
for the object of rendering the property is that he may understand.
Moreover, in addition to this, it is inevitable that those who render
a property after this fashion should be somehow refuted whenever any
one addresses his syllogism to that one of the term's several meanings
which does not agree. For constructive purposes, on the other hand,
see whether both all the terms and also the expression as a whole
avoid bearing more than one sense: for then the property will have
been correctly stated in this respect. Thus (e.g.) seeing that 'body'
does not bear several meanings, nor quickest to move upwards in space',
nor yet the whole expression made by putting them together, it would
be correct in this respect to say that it is a property of fire to
be the 'body quickest to move upwards in space'. 

Next, for destructive purposes, see if the term of which he renders
the property is used in more than one sense, and no distinction has
been drawn as to which of them it is whose property he is stating:
for then the property will not have been correctly rendered. The reasons
why this is so are quite clear from what has been said above: for
the same results are bound to follow. Thus (e.g.) seeing that 'the
knowledge of this' signifies many things for it means (1) the possession
of knowledge by it, (2) the use of its knowledge by it, (3) the existence
of knowledge about it, (4) the use of knowledge about it-no property
of the 'knowledge of this' could be rendered correctly unless he draw
a distinction as to which of these it is whose property he is rendering.
For constructive purposes, a man should see if the term of which he
is rendering the property avoids bearing many senses and is one and
simple: for then the property will have been correctly stated in this
respect. Thus (e.g.) seeing that 'man' is used in a single sense,
'naturally civilized animal' would be correctly stated as a property
of man. 

Next, for destructive purposes, see whether the same term has been
repeated in the property. For people often do this undetected in rendering
'properties' also, just as they do in their 'definitions' as well:
but a property to which this has happened will not have been correctly
stated: for the repetition of it confuses the hearer; thus inevitably
the meaning becomes obscure, and further, such people are thought
to babble. Repetition of the same term is likely to happen in two
ways; one is, when a man repeatedly uses the same word, as would happen
if any one were to render, as a property of fire, 'the body which
is the most rarefied of bodies' (for he has repeated the word 'body');
the second is, if a man replaces words by their definitions, as would
happen if any one were to render, as a property of earth, 'the substance
which is by its nature most easily of all bodies borne downwards in
space', and were then to substitute 'substances of such and such a
kind' for the word 'bodies': for 'body' and 'a substance of such and
such a kind' mean one and the same thing. For he will have repeated
the word 'substance', and accordingly neither of the properties would
be correctly stated. For constructive purposes, on the other hand,
see whether he avoids ever repeating the same term; for then the property
will in this respect have been correctly rendered. Thus (e.g.) seeing
that he who has stated 'animal capable of acquiring knowledge' as
a property of man has avoided repeating the same term several times,
the property would in this respect have been correctly rendered of
man. 

Next, for destructive purposes, see whether he has rendered in the
property any such term as is a universal attribute. For one which
does not distinguish its subject from other things is useless, and
it is the business of the language Of 'properties', as also of the
language of definitions, to distinguish. In the case contemplated,
therefore, the property will not have been correctly rendered. Thus
(e.g.) a man who has stated that it is a property of knowledge to
be a 'conception incontrovertible by argument, because of its unity',
has used in the property a term of that kind, viz. 'unity', which
is a universal attribute; and therefore the property of knowledge
could not have been correctly stated. For constructive purposes, on
the other hand, see whether he has avoided all terms that are common
to everything and used a term that distinguishes the subject from
something: for then the property will in this respect have been correctly
stated. Thus (e.g.) inasmuch as he who has said that it is a property
of a 'living creature' to 'have a soul' has used no term that is common
to everything, it would in this respect have been correctly stated
to be a property of a 'living creature' to 'have a soul'.

Next, for destructive purposes see whether he renders more than one
property of the same thing, without a definite proviso that he is
stating more than one: for then the property will not have been correctly
stated. For just as in the case of definitions too there should be
no further addition beside the expression which shows the essence,
so too in the case of properties nothing further should be rendered
beside the expression that constitutes the property mentioned: for
such an addition is made to no purpose. Thus (e.g.) a man who has
said that it is a property of fire to be 'the most rarefied and lightest
body' has rendered more than one property (for each term is a true
predicate of fire alone); and so it could not be a correctly stated
property of fire to be 'the most rarefied and lightest body'. On the
other hand, for constructive purposes, see whether he has avoided
rendering more than one property of the same thing, and has rendered
one only: for then the property will in this respect have been correctly
stated. Thus (e.g.) a man who has said that it is a property of a
liquid to be a 'body adaptable to every shape' has rendered as its
property a single character and not several, and so the property of
'liquid' would in this respect have been correctly stated.


Part 3

Next, for destructive purposes, see whether he has employed either
the actual subject whose property he is rendering, or any of its species:
for then the property will not have been correctly stated. For the
object of rendering the property is that people may understand: now
the subject itself is just as unintelligible as it was to start with,
while any one of its species is posterior to it, and so is no more
intelligible. Accordingly it is impossible to understand anything
further by the use of these terms. Thus (e.g.) any one who has said
that it is property of 'animal' to be 'the substance to which "man"
belongs as a species' has employed one of its species, and therefore
the property could not have been correctly stated. For constructive
purposes, on the other hand, see whether he avoids introducing either
the subject itself or any of its species: for then the property will
in this respect have been correctly stated. Thus (e.g.) a man who
has stated that it is a property of a living creature to be 'compounded
of soul and body' has avoided introducing among the rest either the
subject itself or any of its species, and therefore in this respect
the property of a 'living creature' would have been correctly rendered.

You should inquire in the same way also in the case of other terms
that do or do not make the subject more intelligible: thus, for destructive
purposes, see whether he has employed anything either opposite to
the subject or, in general, anything simultaneous by nature with it
or posterior to it: for then the property will not have been correctly
stated. For an opposite is simultaneous by nature with its opposite,
and what is simultaneous by nature or is posterior to it does not
make its subject more intelligible. Thus (e.g.) any one who has said
that it is a property of good to be 'the most direct opposite of evil',
has employed the opposite of good, and so the property of good could
not have been correctly rendered. For constructive purposes, on the
other hand, see whether he has avoided employing anything either opposite
to, or, in general, simultaneous by nature with the subject, or posterior
to it: for then the property will in this respect have been correctly
rendered. Thus (e.g.) a man who has stated that it is a property of
knowledge to be 'the most convincing conception' has avoided employing
anything either opposite to, or simultaneous by nature with, or posterior
to, the subject; and so the property of knowledge would in this respect
have been correctly stated. 

Next, for destructive purposes, see whether he has rendered as property
something that does not always follow the subject but sometimes ceases
to be its property: for then the property will not have been correctly
described. For there is no necessity either that the name of the subject
must also be true of anything to which we find such an attribute belonging;
nor yet that the name of the subject will be untrue of anything to
which such an attribute is found not to belong. Moreover, in addition
to this, even after he has rendered the property it will not be clear
whether it belongs, seeing that it is the kind of attribute that may
fall: and so the property will not be clear. Thus (e.g.) a man who
has stated that it is a property of animal 'sometimes to move and
sometimes to stand still' rendered the kind of property which sometimes
is not a property, and so the property could not have been correctly
stated. For constructive purposes, on the other hand, see whether
he has rendered something that of necessity must always be a property:
for then the property will have been in this respect correctly stated.
Thus (e.g.) a man who has stated that it is a property of virtue to
be 'what makes its possessor good' has rendered as property something
that always follows, and so the property of virtue would in this respect
have been correctly rendered. 

Next, for destructive purposes, see whether in rendering the property
of the present time he has omitted to make a definite proviso that
it is the property of the present time which he is rendering: for
else the property will not have been correctly stated. For in the
first place, any unusual procedure always needs a definite proviso:
and it is the usual procedure for everybody to render as property
some attribute that always follows. In the second place, a man who
omits to provide definitely whether it was the property of the present
time which he intended to state, is obscure: and one should not give
any occasion for adverse criticism. Thus (e.g.) a man who has stated
it as the property of a particular man 'to be sitting with a particular
man', states the property of the present time, and so he cannot have
rendered the property correctly, seeing that he has described it without
any definite proviso. For constructive purposes, on the other hand,
see whether, in rendering the property of the present time, he has,
in stating it, made a definite proviso that it is the property of
the present time that he is stating: for then the property will in
this respect have been correctly stated. Thus (e.g.) a man who has
said that it is the property of a particular man 'to be walking now',
has made this distinction in his statement, and so the property would
have been correctly stated. 

Next, for destructive purposes, see whether he has rendered a property
of the kind whose appropriateness is not obvious except by sensation:
for then the property will not have been correctly stated. For every
sensible attribute, once it is taken beyond the sphere of sensation,
becomes uncertain. For it is not clear whether it still belongs, because
it is evidenced only by sensation. This principle will be true in
the case of any attributes that do not always and necessarily follow.
Thus (e.g.) any one who has stated that it is a property of the sun
to be 'the brightest star that moves over the earth', has used in
describing the property an expression of that kind, viz. 'to move
over the earth', which is evidenced by sensation; and so the sun's
property could not have been correctly rendered: for it will be uncertain,
whenever the sun sets, whether it continues to move over the earth,
because sensation then fails us. For constructive purposes, on the
other hand, see whether he has rendered the property of a kind that
is not obvious to sensation, or, if it be sensible, must clearly belong
of necessity: for then the property will in this respect have been
correctly stated. Thus (e.g.) a man who has stated that it is a property
of a surface to be 'the primary thing that is coloured', has introduced
amongst the rest a sensible quality, 'to be coloured', but still a
quality such as manifestly always belongs, and so the property of
'surface' would in this respect have been correctly rendered.

Next, for destructive purposes, see whether he has rendered the definition
as a property: for then the property will not have been correctly
stated: for the property of a thing ought not to show its essence.
Thus (e.g.) a man who has said that it is the property of man to be
'a walking, biped animal' has rendered a property of man so as to
signify his essence, and so the property of man could not have been
correctly rendered. For constructive purposes, on the other hand,
see whether the property which he has rendered forms a predicate convertible
with its subject, without, however, signifying its essence: for then
the property will in this respect have been correctly rendered. Thus
(e.g.) he who has stated that it is a property of man to be a 'naturally
civilized animal' has rendered the property so as to be convertible
with its subject, without, however, showing its essence, and so the
property of man' would in this respect have been correctly rendered.

Next, for destructive purposes, see whether he has rendered the property
without having placed the subject within its essence. For of properties,
as also of definitions, the first term to be rendered should be the
genus, and then the rest of it should be appended immediately afterwards,
and should distinguish its subject from other things. Hence a property
which is not stated in this way could not have been correctly rendered.
Thus (e.g.) a man who has said that it is a property of a living creature
to 'have a soul' has not placed 'living creature' within its essence,
and so the property of a living creature could not have been correctly
stated. For constructive purposes, on the other hand, see whether
a man first places within its essence the subject whose property he
is rendering, and then appends the rest: for then the property will
in this respect have been correctly rendered. Thus (e.g.) he who has
stated that is a property of man to be an 'animal capable of receiving
knowledge', has rendered the property after placing the subject within
its essence, and so the property of 'man' would in this respect have
been correctly rendered. 


Part 4

The inquiry, then, whether the property has been correctly rendered
or no, should be made by these means. The question, on the other hand,
whether what is stated is or is not a property at all, you should
examine from the following points of view. For the commonplace arguments
which establish absolutely that the property is accurately stated
will be the same as those that constitute it a property at all: accordingly
they will be described in the course of them. 

Firstly, then, for destructive purposes, take a look at each subject
of which he has rendered the property, and see (e.g.) if it fails
to belong to any of them at all, or to be true of them in that particular
respect, or to be a property of each of them in respect of that character
of which he has rendered the property: for then what is stated to
be a property will not be a property. Thus, for example, inasmuch
as it is not true of the geometrician that he 'cannot be deceived
by an argument' (for a geometrician is deceived when his figure is
misdrawn), it could not be a property of the man of science that he
is not deceived by an argument. For constructive purposes, on the
other hand, see whether the property rendered be true of every instance,
and true in that particular respect: for then what is stated not to
be a property will be a property. Thus, for example, in as much as
the description 'an animal capable of receiving knowledge' is true
of every man, and true of him qua man, it would be a property of man
to be 'an animal capable of receiving knowledge'. commonplace rule
means-for destructive purposes, see if the description fails to be
true of that of which the name is true; and if the name fails to be
true of that of which the description is true: for constructive purposes,
on the other hand, see if the description too is predicated of that
of which the name is predicated, and if the name too is predicated
of that of which the description is predicated.] 

Next, for destructive purposes, see if the description fails to apply
to that to which the name applies, and if the name fails to apply
to that to which the description applies: for then what is stated
to be a property will not be a property. Thus (e.g.) inasmuch as the
description 'a living being that partakes of knowledge' is true of
God, while 'man' is not predicated of God, to be a living being that
partakes of knowledge' could not be a property of man. For constructive
purposes, on the other hand, see if the name as well be predicated
of that of which the description is predicated, and if the description
as well be predicated of that of which the name is predicated. For
then what is stated not to be a property will be a property. Thus
(e.g.) the predicate 'living creature' is true of that of which 'having
a soul' is true, and 'having a soul' is true of that of which the
predicate 'living creature' is true; and so 'having a soul would be
a property of 'living creature'. 

Next, for destructive purposes, see if he has rendered a subject as
a property of that which is described as 'in the subject': for then
what has been stated to be a property will not be a property. Thus
(e.g.) inasmuch as he who has rendered 'fire' as the property of 'the
body with the most rarefied particles', has rendered the subject as
the property of its predicate, 'fire' could not be a property of 'the
body with the most rarefied particles'. The reason why the subject
will not be a property of that which is found in the subject is this,
that then the same thing will be the property of a number of things
that are specifically different. For the same thing has quite a number
of specifically different predicates that belong to it alone, and
the subject will be a property of all of these, if any one states
the property in this way. For constructive purposes, on the other
hand, see if he has rendered what is found in the subject as a property
of the subject: for then what has been stated not to be a property
will be a property, if it be predicated only of the things of which
it has been stated to be the property. Thus (e.g.) he who has said
that it is a property of 'earth' to be 'specifically the heaviest
body' has rendered of the subject as its property something that is
said of the thing in question alone, and is said of it in the manner
in which a property is predicated, and so the property of earth would
have been rightly stated. 

Next, for destructive purposes, see if he has rendered the property
as partaken of: for then what is stated to be a property will not
be a property. For an attribute of which the subject partakes is a
constituent part of its essence: and an attribute of that kind would
be a differentia applying to some one species. E.g. inasmuch as he
who has said that 'walking on two feet' is property of man has rendered
the property as partaken of, 'walking on two feet' could not be a
property of 'man'. For constructive purposes, on the other hand, see
if he has avoided rendering the property as partaken of, or as showing
the essence, though the subject is predicated convertibly with it:
for then what is stated not to be a property will be a property. Thus
(e.g.) he who has stated that to be 'naturally sentient' is a property
of 'animal' has rendered the property neither as partaken of nor as
showing the essence, though the subject is predicated convertibly
with it; and so to be 'naturally sentient' would be a property of
'animal'. 

Next, for destructive purposes, see if the property cannot possibly
belong simultaneously, but must belong either as posterior or as prior
to the attribute described in the name: for then what is stated to
be a property will not be a property either never, or not always.
Thus (e.g.) inasmuch as it is possible for the attribute 'walking
through the market-place' to belong to an object as prior and as posterior
to the attribute 'man', 'walking through the market-place' could not
be a property of 'man' either never, or not always. For constructive
purposes, on the other hand, see if it always and of necessity belongs
simultaneously, without being either a definition or a differentia:
for then what is stated not to be a property will be a property. Thus
(e.g.) the attribute 'an animal capable of receiving knowledge' always
and of necessity belongs simultaneously with the attribute 'man',
and is neither differentia nor definition of its subject, and so 'an
animal capable of receiving knowledge' would be a property of 'man'.

Next, for destructive purposes, see if the same thing fails to be
a property of things that are the same as the subject, so far as they
are the same: for then what is stated to be a property will not be
a property. Thus, for example, inasmuch as it is no property of a
'proper object of pursuit' to 'appear good to certain persons', it
could not be a property of the 'desirable' either to 'appear good
to certain persons': for 'proper object of pursuit' and 'desirable'
mean the same. For constructive purposes, on the other hand, see if
the same thing be a property of something that is the same as the
subject, in so far as it is the same. For then is stated not to be
a property will be a property. Thus (e.g.) inasmuch as it is called
a property of a man, in so far as he is a man, 'to have a tripartite
soul', it would also be a property of a mortal, in so far as he is
a mortal, to have a tripartite soul. This commonplace rule is useful
also in dealing with Accident: for the same attributes ought either
to belong or not belong to the same things, in so far as they are
the same. 

Next, for destructive purposes, see if the property of things that
are the same in kind as the subject fails to be always the same in
kind as the alleged property: for then neither will what is stated
to be the property of the subject in question. Thus (e.g.) inasmuch
as a man and a horse are the same in kind, and it is not always a
property of a horse to stand by its own initiative, it could not be
a property of a man to move by his own initiative; for to stand and
to move by his own initiative are the same in kind, because they belong
to each of them in so far as each is an 'animal'. For constructive
purposes, on the other hand, see if of things that are the same in
kind as the subject the property that is the same as the alleged property
is always true: for then what is stated not to be a property will
be a property. Thus (e.g.) since it is a property of man to be a 'walking
biped,' it would also be a property of a bird to be a 'flying biped':
for each of these is the same in kind, in so far as the one pair have
the sameness of species that fall under the same genus, being under
the genus 'animal', while the other pair have that of differentiae
of the genus, viz. of 'animal'. This commonplace rule is deceptive
whenever one of the properties mentioned belongs to some one species
only while the other belongs to many, as does 'walking quadruped'.

Inasmuch as 'same' and 'different' are terms used in several senses,
it is a job to render to a sophistical questioner a property that
belongs to one thing and that only. For an attribute that belongs
to something qualified by an accident will also belong to the accident
taken along with the subject which it qualifies; e.g. an attribute
that belongs to 'man' will belong also to 'white man', if there be
a white man, and one that belongs to 'white man' will belong also
to 'man'. One might, then, bring captious criticism against the majority
of properties, by representing the subject as being one thing in itself,
and another thing when combined with its accident, saying, for example,
that 'man' is one thing, and white man' another, and moreover by representing
as different a certain state and what is called after that state.
For an attribute that belongs to the state will belong also to what
is called after that state, and one that belongs to what is called
after a state will belong also to the state: e.g. inasmuch as the
condition of the scientist is called after his science, it could not
be a property of 'science' that it is 'incontrovertible by argument';
for then the scientist also will be incontrovertible by argument.
For constructive purposes, however, you should say that the subject
of an accident is not absolutely different from the accident taken
along with its subject; though it is called 'another' thing because
the mode of being of the two is different: for it is not the same
thing for a man to be a man and for a white man to be a white man.
Moreover, you should take a look along at the inflections, and say
that the description of the man of science is wrong: one should say
not 'it' but 'he is incontrovertible by argument'; while the description
of Science is wrong too: one should say not 'it' but 'she is incontrovertible
by argument'. For against an objector who sticks at nothing the defence
should stick at nothing. 


Part 5

Next, for destructive purposes, see if, while intending to render
an attribute that naturally belongs, he states it in his language
in such a way as to indicate one that invariably belongs: for then
it would be generally agreed that what has been stated to be a property
is upset. Thus (e.g.) the man who has said that 'biped' is a property
of man intends to render the attribute that naturally belongs, but
his expression actually indicates one that invariably belongs: accordingly,
'biped' could not be a property of man: for not every man is possessed
of two feet. For constructive purposes, on the other hand, see if
he intends to render the property that naturally belongs, and indicates
it in that way in his language: for then the property will not be
upset in this respect. Thus (e.g.) he who renders as a property of
'man' the phrase 'an animal capable of receiving knowledge' both intends,
and by his language indicates, the property that belongs by nature,
and so 'an animal capable of receiving knowledge' would not be upset
or shown in that respect not to be a property of man. 

Moreover, as regards all the things that are called as they are primarily
after something else, or primarily in themselves, it is a job to render
the property of such things. For if you render a property as belonging
to the subject that is so called after something else, then it will
be true of its primary subject as well; whereas if you state it of
its primary subject, then it will be predicated also of the thing
that is so called after this other. Thus (e.g.) if any one renders
, coloured' as the property of 'surface', 'coloured' will be true
of body as well; whereas if he render it of 'body', it will be predicated
also of 'surface'. Hence the name as well will not be true of that
of which the description is true. 

In the case of some properties it mostly happens that some error is
incurred because of a failure to define how as well as to what things
the property is stated to belong. For every one tries to render as
the property of a thing something that belongs to it either naturally,
as 'biped' belongs to 'man', or actually, as 'having four fingers'
belongs to a particular man, or specifically, as 'consisting of most
rarefied particles' belongs to 'fire', or absolutely, as 'life' to
'living being', or one that belongs to a thing only as called after
something else, as 'wisdom' to the 'soul', or on the other hand primarily,
as 'wisdom' to the 'rational faculty', or because the thing is in
a certain state, as 'incontrovertible by argument' belongs to a 'scientist'
(for simply and solely by reason of his being in a certain state will
he be 'incontrovertible by argument'), or because it is the state
possessed by something, as 'incontrovertible by argument' belongs
to 'science', or because it is partaken of, as 'sensation' belongs
to 'animal' (for other things as well have sensation, e.g. man, but
they have it because they already partake of 'animal'), or because
it partakes of something else, as 'life' belongs to a particular kind
of 'living being'. Accordingly he makes a mistake if he has failed
to add the word 'naturally', because what belongs naturally may fail
to belong to the thing to which it naturally belongs, as (e.g.) it
belongs to a man to have two feet: so too he errs if he does not make
a definite proviso that he is rendering what actually belongs, because
one day that attribute will not be what it now is, e.g. the man's
possession of four fingers. So he errs if he has not shown that he
states a thing to be such and such primarily, or that he calls it
so after something else, because then its name too will not be true
of that of which the description is true, as is the case with 'coloured',
whether rendered as a property of 'surface' or of 'body'. So he errs
if he has not said beforehand that he has rendered a property to a
thing either because that thing possesses a state, or because it is
a state possessed by something; because then it will not be a property.
For, supposing he renders the property to something as being a state
possessed, it will belong to what possesses that state; while supposing
he renders it to what possesses the state, it will belong to the state
possessed, as did 'incontrovertible by argument' when stated as a
property of 'science' or of the 'scientist'. So he errs if he has
not indicated beforehand that the property belongs because the thing
partakes of, or is partaken of by, something; because then the property
will belong to certain other things as well. For if he renders it
because its subject is partaken of, it will belong to the things which
partake of it; whereas if he renders it because its subject partakes
of something else, it will belong to the things partaken of, as (e.g.)
if he were to state 'life' to be a property of a 'particular kind
of living being', or just of 'living being. So he errs if he has not
expressly distinguished the property that belongs specifically, because
then it will belong only to one of the things that fall under the
term of which he states the property: for the superlative belongs
only to one of them, e.g. 'lightest' as applied to 'fire'. Sometimes,
too, a man may even add the word 'specifically', and still make a
mistake. For the things in question should all be of one species,
whenever the word 'specifically' is added: and in some cases this
does not occur, as it does not, in fact, in the case of fire. For
fire is not all of one species; for live coals and flame and light
are each of them 'fire', but are of different species. The reason
why, whenever 'specifically' is added, there should not be any species
other than the one mentioned, is this, that if there be, then the
property in question will belong to some of them in a greater and
to others in a less degree, as happens with 'consisting of most rarefied
particles' in the case of fire: for 'light' consists of more rarefied
particles than live coals and flame. And this should not happen unless
the name too be predicated in a greater degree of that of which the
description is truer; otherwise the rule that where the description
is truer the name too should be truer is not fulfilled. Moreover,
in addition to this, the same attribute will be the property both
of the term which has it absolutely and of that element therein which
has it in the highest degree, as is the condition of the property
'consisting of most rarefied particles' in the case of 'fire': for
this same attribute will be the property of 'light' as well: for it
is 'light' that 'consists of the most rarefied particles'. If, then,
any one else renders a property in this way one should attack it;
for oneself, one should not give occasion for this objection, but
should define in what manner one states the property at the actual
time of making the statement. 

Next, for destructive purposes, see if he has stated a thing as a
property of itself: for then what has been stated to be a property
will not be a property. For a thing itself always shows its own essence,
and what shows the essence is not a property but a definition. Thus
(e.g.) he who has said that 'becoming' is a property of 'beautiful'
has rendered the term as a property of itself (for 'beautiful' and
'becoming' are the same); and so 'becoming' could not be a property
of 'beautiful'. For constructive purposes, on the other hand, see
if he has avoided rendering a thing as a property of itself, but has
yet stated a convertible predicate: for then what is stated not to
be a property will be a property. Thus he who has stated 'animate
substance' as a property of 'living-creature' has not stated 'living-creature'
as a property of itself, but has rendered a convertible predicate,
so that 'animate substance' would be a property of 'living-creature'.

Next, in the case of things consisting of like parts, you should look
and see, for destructive purposes, if the property of the whole be
not true of the part, or if that of the part be not predicated of
the whole: for then what has been stated to be the property will not
be a property. In some cases it happens that this is so: for sometimes
in rendering a property in the case of things that consist of like
parts a man may have his eye on the whole, while sometimes he may
address himself to what is predicated of the part: and then in neither
case will it have been rightly rendered. Take an instance referring
to the whole: the man who has said that it is a property of the 'sea'
to be 'the largest volume of salt water', has stated the property
of something that consists of like parts, but has rendered an attribute
of such a kind as is not true of the part (for a particular sea is
not 'the largest volume of salt water'); and so the largest volume
of salt water' could not be a property of the 'sea'. Now take one
referring to the part: the man who has stated that it is a property
of 'air' to be 'breathable' has stated the property of something that
consists of like parts, but he has stated an attribute such as, though
true of some air, is still not predicable of the whole (for the whole
of the air is not breathable); and so 'breathable' could not be a
property of 'air'. For constructive purposes, on the other hand, see
whether, while it is true of each of the things with similar parts,
it is on the other hand a property of them taken as a collective whole:
for then what has been stated not to be a property will be a property.
Thus (e.g.) while it is true of earth everywhere that it naturally
falls downwards, it is a property of the various particular pieces
of earth taken as 'the Earth', so that it would be a property of 'earth'
'naturally to fall downwards'. 


Part 6

Next, look from the point of view of the respective opposites, and
first (a) from that of the contraries, and see, for destructive purposes,
if the contrary of the term rendered fails to be a property of the
contrary subject. For then neither will the contrary of the first
be a property of the contrary of the second. Thus (e.g.) inasmuch
as injustice is contrary to justice, and the lowest evil to the highest
good, but 'to be the highest good' is not a property of 'justice',
therefore 'to be the lowest evil' could not be a property of 'injustice'.
For constructive purposes, on the other hand, see if the contrary
is the property of the contrary: for then also the contrary of the
first will be the property of the contrary of the second. Thus (e.g.)
inasmuch as evil is contrary to good, and objectionable to desirable,
and 'desirable' is a property of 'good', 'objectionable' would be
a property of 'evil'. 

Secondly (h) look from the point of view of relative opposites and
see, for destructive purposes, if the correlative of the term rendered
fails to be a property of the correlative of the subject: for then
neither will the correlative of the first be a property of the correlative
of the second. Thus (e.g.) inasmuch as 'double' is relative to 'half',
and 'in excess' to 'exceeded', while 'in excess' is not a property
of 'double', exceeded' could not be a property of 'half'. For constructive
purposes, on the other hand, see if the correlative of the alleged
property is a property of the subject's correlative: for then also
the correlative of the first will be a property of the correlative
of the second: e.g. inasmuch as 'double' is relative to 'half', and
the proportion 1:2 is relative to the proportion 2:1, while it is
a property of 'double' to be 'in the proportion of 2 to 1', it would
be a property of 'half' to be 'in the proportion of 1 to 2'.

Thirdly (c) for destructive purposes, see if an attribute described
in terms of a state (X) fails to be a property of the given state
(Y): for then neither will the attribute described in terms of the
privation (of X) be a property of the privation (of Y). Also if, on
the other hand, an attribute described in terms of the privation (of
X) be not a property of the given privation (of Y), neither will the
attribute described in terms of the state (X) be a property of the
state (Y). Thus, for example, inasmuch as it is not predicated as
a property of 'deafness' to be a 'lack of sensation', neither could
it be a property of 'hearing' to be a 'sensation'. For constructive
purposes, on the other hand, see if an attribute described in terms
of a state (X) is a property of the given state (Y): for then also
the attribute that is described in terms of the privation (of X) will
be a property of the privation (of Y). Also, if an attribute described
in terms of a privation (of X) be a property of the privation (of
Y), then also the attribute that is described in terms of the state
(X) will be a property of the state (Y). Thus (e.g.) inasmuch as 'to
see' is a property of 'sight', inasmuch as we have sight, 'failure
to see' would be a property of 'blindness', inasmuch as we have not
got the sight we should naturally have. 

Next, look from the point of view of positive and negative terms;
and first (a) from the point of view of the predicates taken by themselves.
This common-place rule is useful only for a destructive purpose. Thus
(e.g.) see if the positive term or the attribute described in terms
of it is a property of the subject: for then the negative term or
the attribute described in terms of it will not be a property of the
subject. Also if, on the other hand, the negative term or the attribute
described in terms of it is a property of the subject, then the positive
term or the attribute described in terms of it will not be a property
of the subject: e.g. inasmuch as 'animate' is a property of 'living
creature', 'inanimate' could not be a property of 'living creature'.

Secondly (b) look from the point of view of the predicates, positive
or negative, and their respective subjects; and see, for destructive
purposes, if the positive term falls to be a property of the positive
subject: for then neither will the negative term be a property of
the negative subject. Also, if the negative term fails to be a property
of the negative subject, neither will the positive term be a property
of the positive subject. Thus (e.g.) inasmuch as 'animal' is not a
property of 'man', neither could 'not-animal' be a property of 'not-man'.
Also if 'not-animal' seems not to be a property of 'not-man', neither
will 'animal' be a property of 'man'. For constructive purposes, on
the other hand, see if the positive term is a property of the positive
subject: for then the negative term will be a property of the negative
subject as well. Also if the negative term be a property of the negative
subject, the positive will be a property of the positive as well.
Thus (e.g.) inasmuch as it is a property of 'not-living being' 'not
to live', it would be a property of 'living being' 'to live': also
if it seems to be a property of 'living being' 'to live', it will
also seem to be a property of 'not-living being' 'not to live'.

Thirdly (c) look from the point of view of the subjects taken by themselves,
and see, for destructive purposes, if the property rendered is a property
of the positive subject: for then the same term will not be a property
of the negative subject as well. Also, if the term rendered be a property
of the negative subject, it will not be a property of the positive.
Thus (e.g.) inasmuch as 'animate' is a property of 'living creature',
'animate' could not be a property of 'not-living creature'. For constructive
purposes, on the other hand, if the term rendered fails to be a property
of the affirmative subject it would be a property of the negative.
This commonplace rule is, however, deceptive: for a positive term
is not a property of a negative, or a negative of a positive. For
a positive term does not belong at all to a negative, while a negative
term, though it belongs to a positive, does not belong as a property.

Next, look from the point of view of the coordinate members of a division,
and see, for destructive purposes, if none of the co-ordinate members
(parallel with the property rendered) be a property of any of the
remaining set of co-ordinate members (parallel with the subject):
for then neither will the term stated be a property of that of which
it is stated to be a property. Thus (e.g.) inasmuch as 'sensible living
being' is not a property of any of the other living beings, 'intelligible
living being' could not be a property of God. For constructive purposes,
on the other hand, see if some one or other of the remaining co-ordinate
members (parallel with the property rendered) be a property of each
of these co-ordinate members (parallel with the subject): for then
the remaining one too will be a property of that of which it has been
stated not to be a property. Thus (e.g.) inasmuch as it is a property
of 'wisdom' to be essentially 'the natural virtue of the rational
faculty', then, taking each of the other virtues as well in this way,
it would be a property of 'temperance' to be essentially 'the natural
virtue of the faculty of desire'. 

Next, look from the point of view of the inflexions, and see, for
destructive purposes, if the inflexion of the property rendered fails
to be a property of the inflexion of the subject: for then neither
will the other inflexion be a property of the other inflexion. Thus
(e.g.) inasmuch as 'beautifully' is not a property of 'justly', neither
could 'beautiful' be a property of 'just'. For constructive purposes,
on the other hand, see if the inflexion of the property rendered is
a property of the inflexion of the subject: for then also the other
inflexion will be a property of the other inflexion. Thus (e.g.) inasmuch
as 'walking biped' is a property of man, it would also be any one's
property 'as a man' to be described 'as a walking biped'. Not only
in the case of the actual term mentioned should one look at the inflexions,
but also in the case of its opposites, just as has been laid down
in the case of the former commonplace rules as well.' Thus, for destructive
purposes, see if the inflexion of the opposite of the property rendered
fails to be the property of the inflexion of the opposite of the subject:
for then neither will the inflexion of the other opposite be a property
of the inflexion of the other opposite. Thus (e.g.) inasmuch as 'well'
is not a property of 'justly', neither could 'badly' be a property
of 'unjustly'. For constructive purposes, on the other hand, see if
the inflexion of the opposite of the property originally suggested
is a property of the inflexion of the opposite of the original subject:
for then also the inflexion of the other opposite will be a property
of the inflexion of the other opposite. Thus (e.g.) inasmuch as 'best'
is a property of 'the good', 'worst' also will be a property of 'the
evil'. 


Part 7

Next, look from the point of view of things that are in a like relation,
and see, for destructive purposes, if what is in a relation like that
of the property rendered fails to be a property of what is in a relation
like that of the subject: for then neither will what is in a relation
like that of the first be a property of what is in a relation like
that of the second. Thus (e.g.) inasmuch as the relation of the builder
towards the production of a house is like that of the doctor towards
the production of health, and it is not a property of a doctor to
produce health, it could not be a property of a builder to produce
a house. For constructive purposes, on the other hand, see if what
is in a relation like that of the property rendered is a property
of what is in a relation like that of the subject: for then also what
is in a relation like that of the first will be a property of what
is in a relation like that of the second. Thus (e.g.) inasmuch as
the relation of a doctor towards the possession of ability to produce
health is like that of a trainer towards the possession of ability
to produce vigour, and it is a property of a trainer to possess the
ability to produce vigour, it would be a property of a doctor to possess
the ability to produce health. 

Next look from the point of view of things that are identically related,
and see, for destructive purposes, if the predicate that is identically
related towards two subjects fails to be a property of the subject
which is identically related to it as the subject in question; for
then neither will the predicate that is identically related to both
subjects be a property of the subject which is identically related
to it as the first. If, on the other hand, the predicate which is
identically related to two subjects is the property of the subject
which is identically related to it as the subject in question, then
it will not be a property of that of which it has been stated to be
a property. (e.g.) inasmuch as prudence is identically related to
both the noble and the base, since it is knowledge of each of them,
and it is not a property of prudence to be knowledge of the noble,
it could not be a property of prudence to be knowledge of the base.
If, on the other hand, it is a property of prudence to be the knowledge
of the noble, it could not be a property of it to be the knowledge
of the base.] For it is impossible for the same thing to be a property
of more than one subject. For constructive purposes, on the other
hand, this commonplace rule is of no use: for what is 'identically
related' is a single predicate in process of comparison with more
than one subject. 

Next, for destructive purposes, see if the predicate qualified by
the verb 'to be' fails to be a property of the subject qualified by
the verb 'to be': for then neither will the destruction of the one
be a property of the other qualified by the verb 'to be destroyed',
nor will the 'becoming'the one be a property of the other qualified
by the verb 'to become'. Thus (e.g.) inasmuch as it is not a property
of 'man' to be an animal, neither could it be a property of becoming
a man to become an animal; nor could the destruction of an animal
be a property of the destruction of a man. In the same way one should
derive arguments also from 'becoming' to 'being' and 'being destroyed',
and from 'being destroyed' to 'being' and to 'becoming' exactly as
they have just been given from 'being' to 'becoming' and 'being destroyed'.
For constructive purposes, on the other hand, see if the subject set
down as qualified by the verb 'to be' has the predicate set down as
so qualified, as its property: for then also the subject qualified
by the very 'to become' will have the predicate qualified by 'to become'
as its property, and the subject qualified by the verb to be destroyed'
will have as its property the predicate rendered with this qualification.
Thus, for example, inasmuch as it is a property of man to be a mortal,
it would be a property of becoming a man to become a mortal, and the
destruction of a mortal would be a property of the destruction of
a man. In the same way one should derive arguments also from 'becoming'
and 'being destroyed' both to 'being' and to the conclusions that
follow from them, exactly as was directed also for the purpose of
destruction. 

Next take a look at the 'idea' of the subject stated, and see, for
destructive purposes, if the suggested property fails to belong to
the 'idea' in question, or fails to belong to it in virtue of that
character which causes it to bear the description of which the property
was rendered: for then what has been stated to be a property will
not be a property. Thus (e.g.) inasmuch as 'being motionless' does
not belong to 'man-himself' qua 'man', but qua 'idea', it could not
be a property of 'man' to be motionless. For constructive purposes,
on the other hand, see if the property in question belongs to the
idea, and belongs to it in that respect in virtue of which there is
predicated of it that character of which the predicate in question
has been stated not to be a property: for then what has been stated
not to be a property will be a property. Thus (e.g.) inasmuch as it
belongs to 'living-creature-itself' to be compounded of soul and body,
and further this belongs to it qua 'living-creature', it would be
a property of 'living-creature' to be compounded of soul and body.


Part 8

Next look from the point of view of greater and less degrees, and
first (a) for destructive purposes, see if what is more-P fails to
be a property of what is more-S: for then neither will what is less-P
be a property of what is less-S, nor least-P of least-S, nor most-P
of most-S, nor P simply of S simply. Thus (e.g.) inasmuch as being
more highly coloured is not a property of what is more a body, neither
could being less highly coloured be a property of what is less a body,
nor being coloured be a property of body at all. For constructive
purposes, on the other hand, see if what is more-P is a property of
what is more-S: for then also what is less-P will be a property of
what is less S, and least-P of least-S, and most-P of most-S, and
P simply of S simply. Thus (e.g.) inasmuch as a higher degree of sensation
is a property of a higher degree of life, a lower degree of sensation
also would be a property of a lower degree of life, and the highest
of the highest and the lowest of the lowest degree, and sensation
simply of life simply. 

Also you should look at the argument from a simple predication to
the same qualified types of predication, and see, for destructive
purposes, if P simply fails to be a property of S simply; for then
neither will more-P be a property of more-S, nor less-P of less-S,
nor most-P of most-S, nor least-P of least-S. Thus (e.g.) inasmuch
as 'virtuous' is not a property of 'man', neither could 'more virtuous'
be a property of what is 'more human'. For constructive purposes,
on the other hand, see if P simply is a property of S simply: for
then more P also will be a property of more-S, and less-P of less-S,
and least-P of least-S, and most-P of most-S. Thus (e.g.) a tendency
to move upwards by nature is a property of fire, and so also a greater
tendency to move upwards by nature would be a property of what is
more fiery. In the same way too one should look at all these matters
from the point of view of the others as well. 

Secondly (b) for destructive purposes, see if the more likely property
fails to be a property of the more likely subject: for then neither
will the less likely property be a property of the less likely subject.
Thus (e.g.) inasmuch as 'perceiving' is more likely to be a property
of 'animal' than 'knowing' of 'man', and 'perceiving' is not a property
of 'animal', 'knowing' could not be a property of 'man'. For constructive
purposes, on the other hand, see if the less likely property is a
property of the less likely subject; for then too the more likely
property will be a property of the more likely subject. Thus (e.g.)
inasmuch as 'to be naturally civilized' is less likely to be a property
of man than 'to live' of an animal, and it is a property of man to
be naturally civilized, it would be a property of animal to live.

Thirdly (c) for destructive purposes, see if the predicate fails to
be a property of that of which it is more likely to be a property:
for then neither will it be a property of that of which it is less
likely to be a property: while if it is a property of the former,
it will not be a property of the latter. Thus (e.g.) inasmuch as 'to
be coloured' is more likely to be a property of a 'surface' than of
a 'body', and it is not a property of a surface, 'to be coloured'
could not be a property of 'body'; while if it is a property of a
'surface', it could not be a property of a 'body'. For constructive
purposes, on the other hand, this commonplace rule is not of any use:
for it is impossible for the same thing to be a property of more than
one thing. 

Fourthly (d) for destructive purposes, see if what is more likely
to be a property of a given subject fails to be its property: for
then neither will what is less likely to be a property of it be its
property. Thus (e.g.) inasmuch as 'sensible' is more likely than 'divisible'
to be a property of 'animal', and 'sensible' is not a property of
animal, 'divisible' could not be a property of animal. For constructive
purposes, on the other hand, see if what is less likely to be a property
of it is a property; for then what is more likely to be a property
of it will be a property as well. Thus, for example, inasmuch as 'sensation'
is less likely to be a property of 'animal' than life', and 'sensation'
is a property of animal, 'life' would be a property of animal.

Next, look from the point of view of the attributes that belong in
a like manner, and first (a) for destructive purposes, see if what
is as much a property fails to be a property of that of which it is
as much a property: for then neither will that which is as much a
property as it be a property of that of which it is as much a property.
Thus (e.g.) inasmuch as 'desiring' is as much a property of the faculty
of desire as reasoning' is a property of the faculty of reason, and
desiring is not a property of the faculty of desire, reasoning could
not be a property of the faculty of reason. For constructive purposes,
on the other hand, see if what is as much a property is a property
of that of which it is as much a property: for then also what is as
much a property as it will be a property of that of which it is as
much a property. Thus (e.g.) inasmuch as it is as much a property
of 'the faculty of reason' to be 'the primary seat of wisdom' as it
is of 'the faculty of desire' to be 'the primary seat of temperance',
and it is a property of the faculty of reason to be the primary seat
of wisdom, it would be a property of the faculty of desire to be the
primary seat of temperance. 

Secondly (b) for destructive purposes, see if what is as much a property
of anything fails to be a property of it: for then neither will what
is as much a property be a property of it. Thus (e.g.) inasmuch as
'seeing' is as much a property of man as 'hearing', and 'seeing' is
not a property of man, 'hearing' could not be a property of man. For
constructive purposes, on the other hand, see if what is as much a
property of it is its property: for then what is as much a property
of it as the former will be its property as well. Thus (e.g.) it is
as much a property of the soul to be the primary possessor of a part
that desires as of a part that reasons, and it is a property of the
soul to be the primary possessor of a part that desires, and so it
be a property of the soul to be the primary possessor of a part that
reasons. 

Thirdly (c) for destructive purposes, see if it fails to be a property
of that of which it is as much a property: for then neither will it
be a property of that of which it is as much a property as of the
former, while if it be a property of the former, it will not be a
property of the other. Thus (e.g.) inasmuch as 'to burn' is as much
a property of 'flame' as of 'live coals', and 'to burn' is not a property
of flame, 'to burn' could not be a property of live coals: while if
it is a property of flame, it could not be a property of live coals.
For constructive purposes, on the other hand, this commonplace rule
is of no use. 

The rule based on things that are in a like relation' differs from
the rule based on attributes that belong in a like manner,' because
the former point is secured by analogy, not from reflection on the
belonging of any attribute, while the latter is judged by a comparison
based on the fact that an attribute belongs. 

Next, for destructive purposes, see if in rendering the property potentially,
he has also through that potentiality rendered the property relatively
to something that does not exist, when the potentiality in question
cannot belong to what does not exist: for then what is stated to be
a property will not be a property. Thus (e.g.) he who has said that
'breathable' is a property of 'air' has, on the one hand, rendered
the property potentially (for that is 'breathable' which is such as
can be breathed), and on the other hand has also rendered the property
relatively to what does not exist:-for while air may exist, even though
there exist no animal so constituted as to breathe the air, it is
not possible to breathe it if no animal exist: so that it will not,
either, be a property of air to be such as can be breathed at a time
when there exists no animal such as to breathe it and so it follows
that 'breathable' could not be a property of air. 

For constructive purposes, see if in rendering the property potentially
he renders the property either relatively to something that exists,
or to something that does not exist, when the potentiality in question
can belong to what does not exist: for then what has been stated not
to be a property will be a property. Thus e.g.) he who renders it
as a property of 'being' to be 'capable of being acted upon or of
acting', in rendering the property potentially, has rendered the property
relatively to something that exists: for when 'being' exists, it will
also be capable of being acted upon or of acting in a certain way:
so that to be 'capable of being acted upon or of acting' would be
a property of 'being'. 

Next, for destructive purposes, see if he has stated the property
in the superlative: for then what has been stated to be a property
will not be a property. For people who render the property in that
way find that of the object of which the description is true, the
name is not true as well: for though the object perish the description
will continue in being none the less; for it belongs most nearly to
something that is in being. An example would be supposing any one
were to render 'the lightest body' as a property of 'fire': for, though
fire perish, there eh re will still be some form of body that is the
lightest, so that 'the lightest body' could not be a property of fire.
For constructive purposes, on the other hand, see if he has avoided
rendering the property in the superlative: for then the property will
in this respect have been property of man has not rendered the property
correctly stated. Thus (e.g.) inasmuch as he in the superlative, the
property would in who states 'a naturally civilized animal' as a this
respect have been correctly stated. 


BOOK VI

Part 1 

The discussion of Definitions falls into five parts. For you have
to show either (1) that it is not true at all to apply the expression
as well to that to which the term is applied (for the definition of
Man ought to be true of every man); or (2) that though the object
has a genus, he has failed to put the object defined into the genus,
or to put it into the appropriate genus (for the framer of a definition
should first place the object in its genus, and then append its differences:
for of all the elements of the definition the genus is usually supposed
to be the principal mark of the essence of what is defined): or (3)
that the expression is not peculiar to the object (for, as we said
above as well, a definition ought to be peculiar): or else (4) see
if, though he has observed all the aforesaid cautions, he has yet
failed to define the object, that is, to express its essence. (5)
It remains, apart from the foregoing, to see if he has defined it,
but defined it incorrectly. 

Whether, then, the expression be not also true of that of which the
term is true you should proceed to examine according to the commonplace
rules that relate to Accident. For there too the question is always
'Is so and so true or untrue?': for whenever we argue that an accident
belongs, we declare it to be true, while whenever we argue that it
does not belong, we declare it to be untrue. If, again, he has failed
to place the object in the appropriate genus, or if the expression
be not peculiar to the object, we must go on to examine the case according
to the commonplace rules that relate to genus and property.

It remains, then, to prescribe how to investigate whether the object
has been either not defined at all, or else defined incorrectly. First,
then, we must proceed to examine if it has been defined incorrectly:
for with anything it is easier to do it than to do it correctly. Clearly,
then, more mistakes are made in the latter task on account of its
greater difficulty. Accordingly the attack becomes easier in the latter
case than in the former. 

Incorrectness falls into two branches: (1) first, the use of obscure
language (for the language of a definition ought to be the very clearest
possible, seeing that the whole purpose of rendering it is to make
something known); (secondly, if the expression used be longer than
is necessary: for all additional matter in a definition is superfluous.
Again, each of the aforesaid branches is divided into a number of
others. 


Part 2

One commonplace rule, then, in regard to obscurity is, See if the
meaning intended by the definition involves an ambiguity with any
other, e.g. 'Becoming is a passage into being', or 'Health is the
balance of hot and cold elements'. Here 'passage' and 'balance' are
ambiguous terms: it is accordingly not clear which of the several
possible senses of the term he intends to convey. Likewise also, if
the term defined be used in different senses and he has spoken without
distinguishing between them: for then it is not clear to which of
them the definition rendered applies, and one can then bring a captious
objection on the ground that the definition does not apply to all
the things whose definition he has rendered: and this kind of thing
is particularly easy in the case where the definer does not see the
ambiguity of his terms. Or, again, the questioner may himself distinguish
the various senses of the term rendered in the definition, and then
institute his argument against each: for if the expression used be
not adequate to the subject in any of its senses, it is clear that
he cannot have defined it in any sense aright. 

Another rule is, See if he has used a metaphorical expression, as,
for instance, if he has defined knowledge as 'unsupplantable', or
the earth as a 'nurse', or temperance as a 'harmony'. For a metaphorical
expression is always obscure. It is possible, also, to argue sophistically
against the user of a metaphorical expression as though he had used
it in its literal sense: for the definition stated will not apply
to the term defined, e.g. in the case of temperance: for harmony is
always found between notes. Moreover, if harmony be the genus of temperance,
then the same object will occur in two genera of which neither contains
the other: for harmony does not contain virtue, nor virtue harmony.
Again, see if he uses terms that are unfamiliar, as when Plato describes
the eye as 'brow-shaded', or a certain spider as poison-fanged', or
the marrow as 'boneformed'. For an unusual phrase is always obscure.

Sometimes a phrase is used neither ambiguously, nor yet metaphorically,
nor yet literally, as when the law is said to be the 'measure' or
'image' of the things that are by nature just. Such phrases are worse
than metaphor; for the latter does make its meaning to some extent
clear because of the likeness involved; for those who use metaphors
do so always in view of some likeness: whereas this kind of phrase
makes nothing clear; for there is no likeness to justify the description
'measure' or 'image', as applied to the law, nor is the law ordinarily
so called in a literal sense. So then, if a man says that the law
is literally a 'measure' or an 'image', he speaks falsely: for an
image is something produced by imitation, and this is not found in
the case of the law. If, on the other hand, he does not mean the term
literally, it is clear that he has used an unclear expression, and
one that is worse than any sort of metaphorical expression.

Moreover, see if from the expression used the definition of the contrary
be not clear; for definitions that have been correctly rendered also
indicate their contraries as well. Or, again, see if, when it is merely
stated by itself, it is not evident what it defines: just as in the
works of the old painters, unless there were an inscription, the figures
used to be unrecognizable. 


Part 3

If, then, the definition be not clear, you should proceed to examine
on lines such as these. If, on the other hand, he has phrased the
definition redundantly, first of all look and see whether he has used
any attribute that belongs universally, either to real objects in
general, or to all that fall under the same genus as the object defined:
for the mention of this is sure to be redundant. For the genus ought
to divide the object from things in general, and the differentia from
any of the things contained in the same genus. Now any term that belongs
to everything separates off the given object from absolutely nothing,
while any that belongs to all the things that fall under the same
genus does not separate it off from the things contained in the same
genus. Any addition, then, of that kind will be pointless.

Or see if, though the additional matter may be peculiar to the given
term, yet even when it is struck out the rest of the expression too
is peculiar and makes clear the essence of the term. Thus, in the
definition of man, the addition 'capable of receiving knowledge' is
superfluous; for strike it out, and still the expression is peculiar
and makes clear his essence. Speaking generally, everything is superfluous
upon whose removal the remainder still makes the term that is being
defined clear. Such, for instance, would also be the definition of
the soul, assuming it to be stated as a 'self-moving number'; for
the soul is just 'the self-moving', as Plato defined it. Or perhaps
the expression used, though appropriate, yet does not declare the
essence, if the word 'number' be eliminated. Which of the two is the
real state of the case it is difficult to determine clearly: the right
way to treat the matter in all cases is to be guided by convenience.
Thus (e.g.) it is said that the definition of phlegm is the 'undigested
moisture that comes first off food'. Here the addition of the word
'undigested' is superfluous, seeing that 'the first' is one and not
many, so that even when undigested' is left out the definition will
still be peculiar to the subject: for it is impossible that both phlegm
and also something else should both be the first to arise from the
food. Or perhaps the phlegm is not absolutely the first thing to come
off the food, but only the first of the undigested matters, so that
the addition 'undigested' is required; for stated the other way the
definition would not be true unless the phlegm comes first of all.

Moreover, see if anything contained in the definition fails to apply
to everything that falls under the same species: for this sort of
definition is worse than those which include an attribute belonging
to all things universally. For in that case, if the remainder of the
expression be peculiar, the whole too will be peculiar: for absolutely
always, if to something peculiar anything whatever that is true be
added, the whole too becomes peculiar. Whereas if any part of the
expression do not apply to everything that falls under the same species,
it is impossible that the expression as a whole should be peculiar:
for it will not be predicated convertibly with the object; e.g. 'a
walking biped animal six feet high': for an expression of that kind
is not predicated convertibly with the term, because the attribute
'six feet high' does not belong to everything that falls under the
same species. 

Again, see if he has said the same thing more than once, saying (e.g.)
'desire' is a 'conation for the pleasant'. For 'desire' is always
'for the pleasant', so that what is the same as desire will also be
'for the pleasant'. Accordingly our definition of desire becomes 'conation-for-the-pleasant':
for the word 'desire' is the exact equivalent of the words 'conation
for-the-pleasant', so that both alike will be 'for the pleasant'.
Or perhaps there is no absurdity in this; for consider this instance:-Man
is a biped': therefore, what is the same as man is a biped: but 'a
walking biped animal' is the same as man, and therefore walking biped
animal is a biped'. But this involves no real absurdity. For 'biped'
is not a predicate of 'walking animal': if it were, then we should
certainly have 'biped' predicated twice of the same thing; but as
a matter of fact the subject said to be a biped is'a walking biped
animal', so that the word 'biped' is only used as a predicate once.
Likewise also in the case of 'desire' as well: for it is not 'conation'
that is said to be 'for the pleasant', but rather the whole idea,
so that there too the predication is only made once. Absurdity results,
not when the same word is uttered twice, but when the same thing is
more than once predicated of a subject; e.g. if he says, like Xenocrates,
that wisdom defines and contemplates reality:' for definition is a
certain type of contemplation, so that by adding the words 'and contemplates'
over again he says the same thing twice over. Likewise, too, those
fail who say that 'cooling' is 'the privation of natural heat'. For
all privation is a privation of some natural attribute, so that the
addition of the word 'natural' is superfluous: it would have been
enough to say 'privation of heat', for the word 'privation' shows
of itself that the heat meant is natural heat. 

Again, see if a universal have been mentioned and then a particular
case of it be added as well, e.g. 'Equity is a remission of what is
expedient and just'; for what is just is a branch of what is expedient
and is therefore included in the latter term: its mention is therefore
redundant, an addition of the particular after the universal has been
already stated. So also, if he defines 'medicine' as 'knowledge of
what makes for health in animals and men', or 'the law' as 'the image
of what is by nature noble and just'; for what is just is a branch
of what is noble, so that he says the same thing more than once.


Part 4

Whether, then, a man defines a thing correctly or incorrectly you
should proceed to examine on these and similar lines. But whether
he has mentioned and defined its essence or no, should be examined
as follows: First of all, see if he has failed to make the definition
through terms that are prior and more intelligible. For the reason
why the definition is rendered is to make known the term stated, and
we make things known by taking not any random terms, but such as are
prior and more intelligible, as is done in demonstrations (for so
it is with all teaching and learning); accordingly, it is clear that
a man who does not define through terms of this kind has not defined
at all. Otherwise, there will be more than one definition of the same
thing: for clearly he who defines through terms that are prior and
more intelligible has also framed a definition, and a better one,
so that both would then be definitions of the same object. This sort
of view, however, does not generally find acceptance: for of each
real object the essence is single: if, then, there are to be a number
of definitions of the same thing, the essence of the object will be
the same as it is represented to be in each of the definitions, and
these representations are not the same, inasmuch as the definitions
are different. Clearly, then, any one who has not defined a thing
through terms that are prior and more intelligible has not defined
it at all. 

The statement that a definition has not been made through more intelligible
terms may be understood in two senses, either supposing that its terms
are absolutely less intelligible, or supposing that they are less
intelligible to us: for either sense is possible. Thus absolutely
the prior is more intelligible than the posterior, a point, for instance,
than a line, a line than a plane, and a plane than a solid; just as
also a unit is more intelligible than a number; for it is the prius
and starting-point of all number. Likewise, also, a letter is more
intelligible than a syllable. Whereas to us it sometimes happens that
the converse is the case: for the solid falls under perception most
of all-more than a plane-and a plane more than a line, and a line
more than a point; for most people learn things like the former earlier
than the latter; for any ordinary intelligence can grasp them, whereas
the others require an exact and exceptional understanding.

Absolutely, then, it is better to try to make what is posterior known
through what is prior, inasmuch as such a way of procedure is more
scientific. Of course, in dealing with persons who cannot recognize
things through terms of that kind, it may perhaps be necessary to
frame the expression through terms that are intelligible to them.
Among definitions of this kind are those of a point, a line, and a
plane, all of which explain the prior by the posterior; for they say
that a point is the limit of a line, a line of a plane, a plane of
a solid. One must, however, not fail to observe that those who define
in this way cannot show the essential nature of the term they define,
unless it so happens that the same thing is more intelligible both
to us and also absolutely, since a correct definition must define
a thing through its genus and its differentiae, and these belong to
the order of things which are absolutely more intelligible than, and
prior to, the species. For annul the genus and differentia, and the
species too is annulled, so that these are prior to the species. They
are also more intelligible; for if the species be known, the genus
and differentia must of necessity be known as well (for any one who
knows what a man is knows also what 'animal' and 'walking' are), whereas
if the genus or the differentia be known it does not follow of necessity
that the species is known as well: thus the species is less intelligible.
Moreover, those who say that such definitions, viz. those which proceed
from what is intelligible to this, that, or the other man, are really
and truly definitions, will have to say that there are several definitions
of one and the same thing. For, as it happens, different things are
more intelligible to different people, not the same things to all;
and so a different definition would have to be rendered to each several
person, if the definition is to be constructed from what is more intelligible
to particular individuals. Moreover, to the same people different
things are more intelligible at different times; first of all the
objects of sense; then, as they become more sharpwitted, the converse;
so that those who hold that a definition ought to be rendered through
what is more intelligible to particular individuals would not have
to render the same definition at all times even to the same person.
It is clear, then, that the right way to define is not through terms
of that kind, but through what is absolutely more intelligible: for
only in this way could the definition come always to be one and the
same. Perhaps, also, what is absolutely intelligible is what is intelligible,
not to all, but to those who are in a sound state of understanding,
just as what is absolutely healthy is what is healthy to those in
a sound state of body. All such points as this ought to be made very
precise, and made use of in the course of discussion as occasion requires.
The demolition of a definition will most surely win a general approval
if the definer happens to have framed his expression neither from
what is absolutely more intelligible nor yet from what is so to us.

One form, then, of the failure to work through more intelligible terms
is the exhibition of the prior through the posterior, as we remarked
before.' Another form occurs if we find that the definition has been
rendered of what is at rest and definite through what is indefinite
and in motion: for what is still and definite is prior to what is
indefinite and in motion. 

Of the failure to use terms that are prior there are three forms:

(1) The first is when an opposite has been defined through its opposite,
e.g.i. good through evil: for opposites are always simultaneous by
nature. Some people think, also, that both are objects of the same
science, so that the one is not even more intelligible than the other.
One must, however, observe that it is perhaps not possible to define
some things in any other way, e.g. the double without the half, and
all the terms that are essentially relative: for in all such cases
the essential being is the same as a certain relation to something,
so that it is impossible to understand the one term without the other,
and accordingly in the definition of the one the other too must be
embraced. One ought to learn up all such points as these, and use
them as occasion may seem to require. 

(2) Another is-if he has used the term defined itself. This passes
unobserved when the actual name of the object is not used, e.g. supposing
any one had defined the sun as a star that appears by day'. For in
bringing in 'day' he brings in the sun. To detect errors of this sort,
exchange the word for its definition, e.g. the definition of 'day'
as the 'passage of the sun over the earth'. Clearly, whoever has said
'the passage of the sun over the earth' has said 'the sun', so that
in bringing in the 'day' he has brought in the sun. 

(3) Again, see if he has defined one coordinate member of a division
by another, e.g. 'an odd number' as 'that which is greater by one
than an even number'. For the co-ordinate members of a division that
are derived from the same genus are simultaneous by nature and 'odd'
and 'even' are such terms: for both are differentiae of number.

Likewise also, see if he has defined a superior through a subordinate
term, e.g. 'An "even number" is "a number divisible into halves"',
or '"the good" is a "state of virtue" '. For 'half' is derived from
'two', and 'two' is an even number: virtue also is a kind of good,
so that the latter terms are subordinate to the former. Moreover,
in using the subordinate term one is bound to use the other as well:
for whoever employs the term 'virtue' employs the term 'good', seeing
that virtue is a certain kind of good: likewise, also, whoever employs
the term 'half' employs the term 'even', for to be 'divided in half'
means to be divided into two, and two is even. 


Part 5

Generally speaking, then, one commonplace rule relates to the failure
to frame the expression by means of terms that are prior and more
intelligible: and of this the subdivisions are those specified above.
A second is, see whether, though the object is in a genus, it has
not been placed in a genus. This sort of error is always found where
the essence of the object does not stand first in the expression,
e.g. the definition of 'body' as 'that which has three dimensions',
or the definition of 'man', supposing any one to give it, as 'that
which knows how to count': for it is not stated what it is that has
three dimensions, or what it is that knows how to count: whereas the
genus is meant to indicate just this, and is submitted first of the
terms in the definition. 

Moreover, see if, while the term to be defined is used in relation
to many things, he has failed to render it in relation to all of them;
as (e.g.) if he define 'grammar' as the 'knowledge how to write from
dictation': for he ought also to say that it is a knowledge how to
read as well. For in rendering it as 'knowledge of writing' has no
more defined it than by rendering it as 'knowledge of reading': neither
in fact has succeeded, but only he who mentions both these things,
since it is impossible that there should be more than one definition
of the same thing. It is only, however, in some cases that what has
been said corresponds to the actual state of things: in some it does
not, e.g. all those terms which are not used essentially in relation
to both things: as medicine is said to deal with the production of
disease and health; for it is said essentially to do the latter, but
the former only by accident: for it is absolutely alien to medicine
to produce disease. Here, then, the man who renders medicine as relative
to both of these things has not defined it any better than he who
mentions the one only. In fact he has done it perhaps worse, for any
one else besides the doctor is capable of producing disease.

Moreover, in a case where the term to be defined is used in relation
to several things, see if he has rendered it as relative to the worse
rather than to the better; for every form of knowledge and potentiality
is generally thought to be relative to the best. 

Again, if the thing in question be not placed in its own proper genus,
one must examine it according to the elementary rules in regard to
genera, as has been said before.' 

Moreover, see if he uses language which transgresses the genera of
the things he defines, defining, e.g. justice as a 'state that produces
equality' or 'distributes what is equal': for by defining it so he
passes outside the sphere of virtue, and so by leaving out the genus
of justice he fails to express its essence: for the essence of a thing
must in each case bring in its genus. It is the same thing if the
object be not put into its nearest genus; for the man who puts it
into the nearest one has stated all the higher genera, seeing that
all the higher genera are predicated of the lower. Either, then, it
ought to be put into its nearest genus, or else to the higher genus
all the differentiae ought to be appended whereby the nearest genus
is defined. For then he would not have left out anything: but would
merely have mentioned the subordinate genus by an expression instead
of by name. On the other hand, he who mentions merely the higher genus
by itself, does not state the subordinate genus as well: in saying
'plant' a man does not specify 'a tree'. 


Part 6

Again, in regard to the differentiae, we must examine in like manner
whether the differentiae, too, that he has stated be those of the
genus. For if a man has not defined the object by the differentiae
peculiar to it, or has mentioned something such as is utterly incapable
of being a differentia of anything, e.g. 'animal' or 'substance',
clearly he has not defined it at all: for the aforesaid terms do not
differentiate anything at all. Further, we must see whether the differentia
stated possesses anything that is co-ordinate with it in a division;
for, if not, clearly the one stated could not be a differentia of
the genus. For a genus is always divided by differentiae that are
co-ordinate members of a division, as, for instance, by the terms
'walking', 'flying', 'aquatic', and 'biped'. Or see if, though the
contrasted differentia exists, it yet is not true of the genus, for
then, clearly, neither of them could be a differentia of the genus;
for differentiae that are co-ordinates in a division with the differentia
of a thing are all true of the genus to which the thing belongs. Likewise,
also, see if, though it be true, yet the addition of it to the genus
fails to make a species. For then, clearly, this could not be a specific
differentia of the genus: for a specific differentia, if added to
the genus, always makes a species. If, however, this be no true differentia,
no more is the one adduced, seeing that it is a co-ordinate member
of a division with this. 

Moreover, see if he divides the genus by a negation, as those do who
define line as 'length without breadth': for this means simply that
it has not any breadth. The genus will then be found to partake of
its own species: for, since of everything either an affirmation or
its negation is true, length must always either lack breadth or possess
it, so that 'length' as well, i.e. the genus of 'line', will be either
with or without breadth. But 'length without breadth' is the definition
of a species, as also is 'length with breadth': for 'without breadth'
and 'with breadth' are differentiae, and the genus and differentia
constitute the definition of the species. Hence the genus would admit
of the definition of its species. Likewise, also, it will admit of
the definition of the differentia, seeing that one or the other of
the aforesaid differentiae is of necessity predicated of the genus.
The usefulness of this principle is found in meeting those who assert
the existence of 'Ideas': for if absolute length exist, how will it
be predicable of the genus that it has breadth or that it lacks it?
For one assertion or the other will have to be true of 'length' universally,
if it is to be true of the genus at all: and this is contrary to the
fact: for there exist both lengths which have, and lengths which have
not, breadth. Hence the only people against whom the rule can be employed
are those who assert that a genus is always numerically one; and this
is what is done by those who assert the real existence of the 'Ideas';
for they allege that absolute length and absolute animal are the genus.

It may be that in some cases the definer is obliged to employ a negation
as well, e.g. in defining privations. For 'blind' means a thing which
cannot see when its nature is to see. There is no difference between
dividing the genus by a negation, and dividing it by such an affirmation
as is bound to have a negation as its co-ordinate in a division, e.g.
supposing he had defined something as 'length possessed of breadth';
for co-ordinate in the division with that which is possessed of breadth
is that which possesses no breadth and that only, so that again the
genus is divided by a negation. 

Again, see if he rendered the species as a differentia, as do those
who define 'contumely' as 'insolence accompanied by jeering'; for
jeering is a kind of insolence, i.e. it is a species and not a differentia.

Moreover, see if he has stated the genus as the differentia, e.g.
'Virtue is a good or noble state: for 'good' is the genus of 'virtue'.
Or possibly 'good' here is not the genus but the differentia, on the
principle that the same thing cannot be in two genera of which neither
contains the other: for 'good' does not include 'state', nor vice
versa: for not every state is good nor every good a 'state'. Both,
then, could not be genera, and consequently, if 'state' is the genus
of virtue, clearly 'good' cannot be its genus: it must rather be the
differentia'. Moreover, 'a state' indicates the essence of virtue,
whereas 'good' indicates not the essence but a quality: and to indicate
a quality is generally held to be the function of the differentia.
See, further, whether the differentia rendered indicates an individual
rather than a quality: for the general view is that the differentia
always expresses a quality. 

Look and see, further, whether the differentia belongs only by accident
to the object defined. For the differentia is never an accidental
attribute, any more than the genus is: for the differentia of a thing
cannot both belong and not belong to it. 

Moreover, if either the differentia or the species, or any of the
things which are under the species, is predicable of the genus, then
he could not have defined the term. For none of the aforesaid can
possibly be predicated of the genus, seeing that the genus is the
term with the widest range of all. Again, see if the genus be predicated
of the differentia; for the general view is that the genus is predicated,
not of the differentia, but of the objects of which the differentia
is predicated. Animal (e.g.) is predicated of 'man' or 'ox' or other
walking animals, not of the actual differentia itself which we predicate
of the species. For if 'animal' is to be predicated of each of its
differentiae, then 'animal' would be predicated of the species several
times over; for the differentiae are predicates of the species. Moreover,
the differentiae will be all either species or individuals, if they
are animals; for every animal is either a species or an individual.

Likewise you must inquire also if the species or any of the objects
that come under it is predicated of the differentia: for this is impossible,
seeing that the differentia is a term with a wider range than the
various species. Moreover, if any of the species be predicated of
it, the result will be that the differentia is a species: if, for
instance, 'man' be predicated, the differentia is clearly the human
race. Again, see if the differentia fails to be prior to the species:
for the differentia ought to be posterior to the genus, but prior
to the species. 

Look and see also if the differentia mentioned belongs to a different
genus, neither contained in nor containing the genus in question.
For the general view is that the same differentia cannot be used of
two non-subaltern genera. Else the result will be that the same species
as well will be in two non-subaltern genera: for each of the differentiae
imports its own genus, e.g. 'walking' and 'biped' import with them
the genus 'animal'. If, then, each of the genera as well is true of
that of which the differentia is true, it clearly follows that the
species must be in two non-subaltern genera. Or perhaps it is not
impossible for the same differentia to be used of two non-subaltern
genera, and we ought to add the words 'except they both be subordinate
members of the same genus'. Thus 'walking animal' and 'flying animal'
are non-subaltern genera, and 'biped' is the differentia of both.
The words 'except they both be subordinate members of the same genus'
ought therefore to be added; for both these are subordinate to 'animal'.
From this possibility, that the same differentia may be used of two
non-subaltern genera, it is clear also that there is no necessity
for the differentia to carry with it the whole of the genus to which
it belongs, but only the one or the other of its limbs together with
the genera that are higher than this, as 'biped' carries with it either
'flying' or 'walking animal'. 

See, too, if he has rendered 'existence in' something as the differentia
of a thing's essence: for the general view is that locality cannot
differentiate between one essence and another. Hence, too, people
condemn those who divide animals by means of the terms 'walking' and
'aquatic', on the ground that 'walking' and 'aquatic' indicate mere
locality. Or possibly in this case the censure is undeserved; for
'aquatic' does not mean 'in' anything; nor does it denote a locality,
but a certain quality: for even if the thing be on the dry land, still
it is aquatic: and likewise a land-animal, even though it be in the
water, will still be a and not an aquatic-animal. But all the same,
if ever the differentia does denote existence in something, clearly
he will have made a bad mistake. 

Again, see if he has rendered an affection as the differentia: for
every affection, if intensified, subverts the essence of the thing,
while the differentia is not of that kind: for the differentia is
generally considered rather to preserve that which it differentiates;
and it is absolutely impossible for a thing to exist without its own
special differentia: for if there be no 'walking', there will be no
'man'. In fact, we may lay down absolutely that a thing cannot have
as its differentia anything in respect of which it is subject to alteration:
for all things of that kind, if intensified, destroy its essence.
If, then, a man has rendered any differentia of this kind, he has
made a mistake: for we undergo absolutely no alteration in respect
of our differentiae. 

Again, see if he has failed to render the differentia of a relative
term relatively to something else; for the differentiae of relative
terms are themselves relative, as in the case also of knowledge. This
is classed as speculative, practical and productive; and each of these
denotes a relation: for it speculates upon something, and produces
something and does something. 

Look and see also if the definer renders each relative term relatively
to its natural purpose: for while in some cases the particular relative
term can be used in relation to its natural purpose only and to nothing
else, some can be used in relation to something else as well. Thus
sight can only be used for seeing, but a strigil can also be used
to dip up water. Still, if any one were to define a strigil as an
instrument for dipping water, he has made a mistake: for that is not
its natural function. The definition of a thing's natural function
is 'that for which it would be used by the prudent man, acting as
such, and by the science that deals specially with that thing'.

Or see if, whenever a term happens to be used in a number of relations,
he has failed to introduce it in its primary relation: e.g. by defining
'wisdom' as the virtue of 'man' or of the 'soul,' rather than of the
'reasoning faculty': for 'wisdom' is the virtue primarily of the reasoning
faculty: for it is in virtue of this that both the man and his soul
are said to be wise. 

Moreover, if the thing of which the term defined has been stated to
be an affection or disposition, or whatever it may be, be unable to
admit it, the definer has made a mistake. For every disposition and
every affection is formed naturally in that of which it is an affection
or disposition, as knowledge, too, is formed in the soul, being a
disposition of soul. Sometimes, however, people make bad mistakes
in matters of this sort, e.g. all those who say that 'sleep' is a
'failure of sensation', or that 'perplexity' is a state of 'equality
between contrary reasonings', or that 'pain' is a 'violent disruption
of parts that are naturally conjoined'. For sleep is not an attribute
of sensation, whereas it ought to be, if it is a failure of sensation.
Likewise, perplexity is not an attribute of opposite reasonings, nor
pain of parts naturally conjoined: for then inanimate things will
be in pain, since pain will be present in them. Similar in character,
too, is the definition of 'health', say, as a 'balance of hot and
cold elements': for then health will be necessarily exhibited by the
hot and cold elements: for balance of anything is an attribute inherent
in those things of which it is the balance, so that health would be
an attribute of them. Moreover, people who define in this way put
effect for cause, or cause for effect. For the disruption of parts
naturally conjoined is not pain, but only a cause of pain: nor again
is a failure of sensation sleep, but the one is the cause of the other:
for either we go to sleep because sensation fails, or sensation fails
because we go to sleep. Likewise also an equality between contrary
reasonings would be generally considered to be a cause of perplexity:
for it is when we reflect on both sides of a question and find everything
alike to be in keeping with either course that we are perplexed which
of the two we are to do. 

Moreover, with regard to all periods of time look and see whether
there be any discrepancy between the differentia and the thing defined:
e.g. supposing the 'immortal' to be defined as a 'living thing immune
at present from destruction'. For a living thing that is immune 'at
present' from destruction will be immortal 'at present'. Possibly,
indeed, in this case this result does not follow, owing to the ambiguity
of the words 'immune at present from destruction': for it may mean
either that the thing has not been destroyed at present, or that it
cannot be destroyed at present, or that at present it is such that
it never can be destroyed. Whenever, then, we say that a living thing
is at present immune from destruction, we mean that it is at present
a living thing of such a kind as never to be destroyed: and this is
equivalent to saying that it is immortal, so that it is not meant
that it is immortal only at present. Still, if ever it does happen
that what has been rendered according to the definition belongs in
the present only or past, whereas what is meant by the word does not
so belong, then the two could not be the same. So, then, this commonplace
rule ought to be followed, as we have said. 


Part 7

You should look and see also whether the term being defined is applied
in consideration of something other than the definition rendered.
Suppose (e.g.) a definition of 'justice' as the 'ability to distribute
what is equal'. This would not be right, for 'just' describes rather
the man who chooses, than the man who is able to distribute what is
equal: so that justice could not be an ability to distribute what
is equal: for then also the most just man would be the man with the
most ability to distribute what is equal. 

Moreover, see if the thing admits of degrees, whereas what is rendered
according to the definition does not, or, vice versa, what is rendered
according to the definition admits of degrees while the thing does
not. For either both must admit them or else neither, if indeed what
is rendered according to the definition is the same as the thing.
Moreover, see if, while both of them admit of degrees, they yet do
not both become greater together: e.g. suppose sexual love to be the
desire for intercourse: for he who is more intensely in love has not
a more intense desire for intercourse, so that both do not become
intensified at once: they certainly should, however, had they been
the same thing. 

Moreover, suppose two things to be before you, see if the term to
be defined applies more particularly to the one to which the content
of the definition is less applicable. Take, for instance, the definition
of 'fire' as the 'body that consists of the most rarefied particles'.
For 'fire' denotes flame rather than light, but flame is less the
body that consists of the most rarefied particles than is light: whereas
both ought to be more applicable to the same thing, if they had been
the same. Again, see if the one expression applies alike to both the
objects before you, while the other does not apply to both alike,
but more particularly to one of them. 

Moreover, see if he renders the definition relative to two things
taken separately: thus, the beautiful' is 'what is pleasant to the
eyes or to the ears": or 'the real' is 'what is capable of being acted
upon or of acting'. For then the same thing will be both beautiful
and not beautiful, and likewise will be both real and not real. For
'pleasant to the ears' will be the same as 'beautiful', so that 'not
pleasant to the ears' will be the same as 'not beautiful': for of
identical things the opposites, too, are identical, and the opposite
of 'beautiful' is 'not beautiful', while of 'pleasant to the ears'
the opposite is not pleasant to the cars': clearly, then, 'not pleasant
to the ears' is the same thing as 'not beautiful'. If, therefore,
something be pleasant to the eyes but not to the ears, it will be
both beautiful and not beautiful. In like manner we shall show also
that the same thing is both real and unreal. 

Moreover, of both genera and differentiae and all the other terms
rendered in definitions you should frame definitions in lieu of the
terms, and then see if there be any discrepancy between them.


Part 8

If the term defined be relative, either in itself or in respect of
its genus, see whether the definition fails to mention that to which
the term, either in itself or in respect of its genus, is relative,
e.g. if he has defined 'knowledge' as an 'incontrovertible conception'
or 'wishing' as 'painless conation'. For of everything relative the
essence is relative to something else, seeing that the being of every
relative term is identical with being in a certain relation to something.
He ought, therefore, to have said that knowledge is 'conception of
a knowable' and that wishing is 'conation for a good'. Likewise, also,
if he has defined 'grammar' as 'knowledge of letters': whereas in
the definition there ought to be rendered either the thing to which
the term itself is relative, or that, whatever it is, to which its
genus is relative. Or see if a relative term has been described not
in relation to its end, the end in anything being whatever is best
in it or gives its purpose to the rest. Certainly it is what is best
or final that should be stated, e.g. that desire is not for the pleasant
but for pleasure: for this is our purpose in choosing what is pleasant
as well. 

Look and see also if that in relation to which he has rendered the
term be a process or an activity: for nothing of that kind is an end,
for the completion of the activity or process is the end rather than
the process or activity itself. Or perhaps this rule is not true in
all cases, for almost everybody prefers the present experience of
pleasure to its cessation, so that they would count the activity as
the end rather than its completion. 

Again see in some cases if he has failed to distinguish the quantity
or quality or place or other differentiae of an object; e.g. the quality
and quantity of the honour the striving for which makes a man ambitious:
for all men strive for honour, so that it is not enough to define
the ambitious man as him who strives for honour, but the aforesaid
differentiae must be added. Likewise, also, in defining the covetous
man the quantity of money he aims at, or in the case of the incontinent
man the quality of the pleasures, should be stated. For it is not
the man who gives way to any sort of pleasure whatever who is called
incontinent, but only he who gives way to a certain kind of pleasure.
Or again, people sometimes define night as a 'shadow on the earth',
or an earthquake as a movement of the earth', or a cloud as 'condensation
of the air', or a wind as a 'movement of the air'; whereas they ought
to specify as well quantity, quality, place, and cause. Likewise,
also, in other cases of the kind: for by omitting any differentiae
whatever he fails to state the essence of the term. One should always
attack deficiency. For a movement of the earth does not constitute
an earthquake, nor a movement of the air a wind, irrespective of its
manner and the amount involved. 

Moreover, in the case of conations, and in any other cases where it
applies, see if the word 'apparent' is left out, e.g. 'wishing is
a conation after the good', or 'desire is a conation after the pleasant'-instead
of saying 'the apparently good', or 'pleasant'. For often those who
exhibit the conation do not perceive what is good or pleasant, so
that their aim need not be really good or pleasant, but only apparently
so. They ought, therefore, to have rendered the definition also accordingly.
On the other hand, any one who maintains the existence of Ideas ought
to be brought face to face with his Ideas, even though he does render
the word in question: for there can be no Idea of anything merely
apparent: the general view is that an Idea is always spoken of in
relation to an Idea: thus absolute desire is for the absolutely pleasant,
and absolute wishing is for the absolutely good; they therefore cannot
be for an apparent good or an apparently pleasant: for the existence
of an absolutely-apparently-good or pleasant would be an absurdity.


Part 9

Moreover, if the definition be of the state of anything, look at what
is in the state, while if it be of what is in the state, look at the
state: and likewise also in other cases of the kind. Thus if the pleasant
be identical with the beneficial, then, too, the man who is pleased
is benefited. Speaking generally, in definitions of this sort it happens
that what the definer defines is in a sense more than one thing: for
in defining knowledge, a man in a sense defines ignorance as well,
and likewise also what has knowledge and what lacks it, and what it
is to know and to be ignorant. For if the first be made clear, the
others become in a certain sense clear as well. We have, then, to
be on our guard in all such cases against discrepancy, using the elementary
principles drawn from consideration of contraries and of coordinates.

Moreover, in the case of relative terms, see if the species is rendered
as relative to a species of that to which the genus is rendered as
relative, e.g. supposing belief to be relative to some object of belief,
see whether a particular belief is made relative to some particular
object of belief: and, if a multiple be relative to a fraction, see
whether a particular multiple be made relative to a particular fraction.
For if it be not so rendered, clearly a mistake has been made.

See, also, if the opposite of the term has the opposite definition,
whether (e.g.) the definition of 'half' is the opposite of that of
'double': for if 'double' is 'that which exceeds another by an equal
amount to that other', 'half' is 'that which is exceeded by an amount
equal to itself'. In the same way, too, with contraries. For to the
contrary term will apply the definition that is contrary in some one
of the ways in which contraries are conjoined. Thus (e.g.) if 'useful'='productive
of good', 'injurious'=productive of evil' or 'destructive of good',
for one or the other of thee is bound to be contrary to the term originally
used. Suppose, then, neither of these things to be the contrary of
the term originally used, then clearly neither of the definitions
rendered later could be the definition of the contrary of the term
originally defined: and therefore the definition originally rendered
of the original term has not been rightly rendered either. Seeing,
moreover, that of contraries, the one is sometimes a word forced to
denote the privation of the other, as (e.g.) inequality is generally
held to be the privation of equality (for 'unequal' merely describes
things that are not equal'), it is therefore clear that that contrary
whose form denotes the privation must of necessity be defined through
the other; whereas the other cannot then be defined through the one
whose form denotes the privation; for else we should find that each
is being interpreted by the other. We must in the case of contrary
terms keep an eye on this mistake, e.g. supposing any one were to
define equality as the contrary of inequality: for then he is defining
it through the term which denotes privation of it. Moreover, a man
who so defines is bound to use in his definition the very term he
is defining; and this becomes clear, if for the word we substitute
its definition. For to say 'inequality' is the same as to say 'privation
of equality'. Therefore equality so defined will be 'the contrary
of the privation of equality', so that he would have used the very
word to be defined. Suppose, however, that neither of the contraries
be so formed as to denote privation, but yet the definition of it
be rendered in a manner like the above, e.g. suppose 'good' to be
defined as 'the contrary of evil', then, since it is clear that 'evil'
too will be 'the contrary of good' (for the definition of things that
are contrary in this must be rendered in a like manner), the result
again is that he uses the very term being defined: for 'good' is inherent
in the definition of 'evil'. If, then, 'good' be the contrary of evil,
and evil be nothing other than the 'contrary of good', then 'good'
will be the 'contrary of the contrary of good'. Clearly, then, he
has used the very word to be defined. 

Moreover, see if in rendering a term formed to denote privation, he
has failed to render the term of which it is the privation, e.g. the
state, or contrary, or whatever it may be whose privation it is: also
if he has omitted to add either any term at all in which the privation
is naturally formed, or else that in which it is naturally formed
primarily, e.g. whether in defining 'ignorance' a privation he has
failed to say that it is the privation of 'knowledge'; or has failed
to add in what it is naturally formed, or, though he has added this,
has failed to render the thing in which it is primarily formed, placing
it (e.g.) in 'man' or in 'the soul', and not in the 'reasoning faculty':
for if in any of these respects he fails, he has made a mistake. Likewise,
also, if he has failed to say that 'blindness' is the 'privation of
sight in an eye': for a proper rendering of its essence must state
both of what it is the privation and what it is that is deprived.

Examine further whether he has defined by the expression 'a privation'
a term that is not used to denote a privation: thus a mistake of this
sort also would be generally thought to be incurred in the case of
'error' by any one who is not using it as a merely negative term.
For what is generally thought to be in error is not that which has
no knowledge, but rather that which has been deceived, and for this
reason we do not talk of inanimate things or of children as 'erring'.
'Error', then, is not used to denote a mere privation of knowledge.


Part 10

Moreover, see whether the like inflexions in the definition apply
to the like inflexions of the term; e.g. if 'beneficial' means 'productive
of health', does 'beneficially' mean productively of health' and a
'benefactor' a 'producer of health'? 

Look too and see whether the definition given will apply to the Idea
as well. For in some cases it will not do so; e.g. in the Platonic
definition where he adds the word 'mortal' in his definitions of living
creatures: for the Idea (e.g. the absolute Man) is not mortal, so
that the definition will not fit the Idea. So always wherever the
words 'capable of acting on' or 'capable of being acted upon' are
added, the definition and the Idea are absolutely bound to be discrepant:
for those who assert the existence of Ideas hold that they are incapable
of being acted upon, or of motion. In dealing with these people even
arguments of this kind are useful. 

Further, see if he has rendered a single common definition of terms
that are used ambiguously. For terms whose definition corresponding
their common name is one and the same, are synonymous; if, then, the
definition applies in a like manner to the whole range of the ambiguous
term, it is not true of any one of the objects described by the term.
This is, moreover, what happens to Dionysius' definition of 'life'
when stated as 'a movement of a creature sustained by nutriment, congenitally
present with it': for this is found in plants as much as in animals,
whereas 'life' is generally understood to mean not one kind of thing
only, but to be one thing in animals and another in plants. It is
possible to hold the view that life is a synonymous term and is always
used to describe one thing only, and therefore to render the definition
in this way on purpose: or it may quite well happen that a man may
see the ambiguous character of the word, and wish to render the definition
of the one sense only, and yet fail to see that he has rendered a
definition common to both senses instead of one peculiar to the sense
he intends. In either case, whichever course he pursues, he is equally
at fault. Since ambiguous terms sometimes pass unobserved, it is best
in questioning to treat such terms as though they were synonymous
(for the definition of the one sense will not apply to the other,
so that the answerer will be generally thought not to have defined
it correctly, for to a synonymous term the definition should apply
in its full range), whereas in answering you should yourself distinguish
between the senses. Further, as some answerers call 'ambiguous' what
is really synonymous, whenever the definition rendered fails to apply
universally, and, vice versa, call synonymous what is really ambiguous
supposing their definition applies to both senses of the term, one
should secure a preliminary admission on such points, or else prove
beforehand that so-and-so is ambiguous or synonymous, as the case
may be: for people are more ready to agree when they do not foresee
what the consequence will be. If, however, no admission has been made,
and the man asserts that what is really synonymous is ambiguous because
the definition he has rendered will not apply to the second sense
as well, see if the definition of this second meaning applies also
to the other meanings: for if so, this meaning must clearly be synonymous
with those others. Otherwise, there will be more than one definition
of those other meanings, for there are applicable to them two distinct
definitions in explanation of the term, viz. the one previously rendered
and also the later one. Again, if any one were to define a term used
in several senses, and, finding that his definition does not apply
to them all, were to contend not that the term is ambiguous, but that
even the term does not properly apply to all those senses, just because
his definition will not do so either, then one may retort to such
a man that though in some things one must not use the language of
the people, yet in a question of terminology one is bound to employ
the received and traditional usage and not to upset matters of that
sort. 


Part 11

Suppose now that a definition has been rendered of some complex term,
take away the definition of one of the elements in the complex, and
see if also the rest of the definition defines the rest of it: if
not, it is clear that neither does the whole definition define the
whole complex. Suppose, e.g. that some one has defined a 'finite straight
line' as 'the limit of a finite plane, such that its centre is in
a line with its extremes'; if now the definition of a finite line'
be the 'limit of a finite plane', the rest (viz. 'such that its centre
is in a line with its extremes') ought to be a definition of straight'.
But an infinite straight line has neither centre nor extremes and
yet is straight so that this remainder does not define the remainder
of the term. 

Moreover, if the term defined be a compound notion, see if the definition
rendered be equimembral with the term defined. A definition is said
to be equimembral with the term defined when the number of the elements
compounded in the latter is the same as the number of nouns and verbs
in the definition. For the exchange in such cases is bound to be merely
one of term for term, in the case of some if not of all, seeing that
there are no more terms used now than formerly; whereas in a definition
terms ought to be rendered by phrases, if possible in every case,
or if not, in the majority. For at that rate, simple objects too could
be defined by merely calling them by a different name, e.g. 'cloak'
instead of 'doublet'. 

The mistake is even worse, if actually a less well known term be substituted,
e.g. 'pellucid mortal' for 'white man': for it is no definition, and
moreover is less intelligible when put in that form. 

Look and see also whether, in the exchange of words, the sense fails
still to be the same. Take, for instance, the explanation of 'speculative
knowledge' as 'speculative conception': for conception is not the
same as knowledge-as it certainly ought to be if the whole is to be
the same too: for though the word 'speculative' is common to both
expressions, yet the remainder is different. 

Moreover, see if in replacing one of the terms by something else he
has exchanged the genus and not the differentia, as in the example
just given: for 'speculative' is a less familiar term than knowledge;
for the one is the genus and the other the differentia, and the genus
is always the most familiar term of all; so that it is not this, but
the differentia, that ought to have been changed, seeing that it is
the less familiar. It might be held that this criticism is ridiculous:
because there is no reason why the most familiar term should not describe
the differentia, and not the genus; in which case, clearly, the term
to be altered would also be that denoting the genus and not the differentia.
If, however, a man is substituting for a term not merely another term
but a phrase, clearly it is of the differentia rather than of the
genus that a definition should be rendered, seeing that the object
of rendering the definition is to make the subject familiar; for the
differentia is less familiar than the genus. 

If he has rendered the definition of the differentia, see whether
the definition rendered is common to it and something else as well:
e.g. whenever he says that an odd number is a 'number with a middle',
further definition is required of how it has a middle: for the word
'number' is common to both expressions, and it is the word 'odd' for
which the phrase has been substituted. Now both a line and a body
have a middle, yet they are not 'odd'; so that this could not be a
definition of 'odd'. If, on the other hand, the phrase 'with a middle'
be used in several senses, the sense here intended requires to be
defined. So that this will either discredit the definition or prove
that it is no definition at all. 


Part 12

Again, see if the term of which he renders the definition is a reality,
whereas what is contained in the definition is not, e.g. Suppose 'white'
to be defined as 'colour mingled with fire': for what is bodiless
cannot be mingled with body, so that 'colour' 'mingled with fire'
could not exist, whereas 'white' does exist. 

Moreover, those who in the case of relative terms do not distinguish
to what the object is related, but have described it only so as to
include it among too large a number of things, are wrong either wholly
or in part; e.g. suppose some one to have defined 'medicine' as a
science of Reality'. For if medicine be not a science of anything
that is real, the definition is clearly altogether false; while if
it be a science of some real thing, but not of another, it is partly
false; for it ought to hold of all reality, if it is said to be of
Reality essentially and not accidentally: as is the case with other
relative terms: for every object of knowledge is a term relative to
knowledge: likewise, also, with other relative terms, inasmuch as
all such are convertible. Moreover, if the right way to render account
of a thing be to render it as it is not in itself but accidentally,
then each and every relative term would be used in relation not to
one thing but to a number of things. For there is no reason why the
same thing should not be both real and white and good, so that it
would be a correct rendering to render the object in relation to any
one whatsoever of these, if to render what it is accidentally be a
correct way to render it. It is, moreover, impossible that a definition
of this sort should be peculiar to the term rendered: for not only
but the majority of the other sciences too, have for their object
some real thing, so that each will be a science of reality. Clearly,
then, such a definition does not define any science at all; for a
definition ought to be peculiar to its own term, not general.

Sometimes, again, people define not the thing but only the thing in
a good or perfect condition. Such is the definition of a rhetorician
as 'one who can always see what will persuade in the given circumstances,
and omit nothing'; or of a thief, as 'one who pilfers in secret':
for clearly, if they each do this, then the one will be a good rhetorician,
and the other a good thief: whereas it is not the actual pilfering
in secret, but the wish to do it, that constitutes the thief.

Again, see if he has rendered what is desirable for its own sake as
desirable for what it produces or does, or as in any way desirable
because of something else, e.g. by saying that justice is 'what preserves
the laws' or that wisdom is 'what produces happiness'; for what produces
or preserves something else is one of the things desirable for something
else. It might be said that it is possible for what is desirable in
itself to be desirable for something else as well: but still to define
what is desirable in itself in such a way is none the less wrong:
for the essence contains par excellence what is best in anything,
and it is better for a thing to be desirable in itself than to be
desirable for something else, so that this is rather what the definition
too ought to have indicated. 


Part 13

See also whether in defining anything a man has defined it as an 'A
and B', or as a 'product of A and B' or as an 'A+B'. If he defines
it as and B', the definition will be true of both and yet of neither
of them; suppose, e.g. justice to be defined as 'temperance and courage.'
For if of two persons each has one of the two only, both and yet neither
will be just: for both together have justice, and yet each singly
fails to have it. Even if the situation here described does not so
far appear very absurd because of the occurrence of this kind of thing
in other cases also (for it is quite possible for two men to have
a mina between them, though neither of them has it by himself), yet
least that they should have contrary attributes surely seems quite
absurd; and yet this will follow if the one be temperate and yet a
coward, and the other, though brave, be a profligate; for then both
will exhibit both justice and injustice: for if justice be temperance
and bravery, then injustice will be cowardice and profligacy. In general,
too, all the ways of showing that the whole is not the same as the
sum of its parts are useful in meeting the type just described; for
a man who defines in this way seems to assert that the parts are the
same as the whole. The arguments are particularly appropriate in cases
where the process of putting the parts together is obvious, as in
a house and other things of that sort: for there, clearly, you may
have the parts and yet not have the whole, so that parts and whole
cannot be the same. 

If, however, he has said that the term being defined is not 'A and
B' but the 'product of A and B', look and see in the first place if
A and B cannot in the nature of things have a single product: for
some things are so related to one another that nothing can come of
them, e.g. a line and a number. Moreover, see if the term that has
been defined is in the nature of things found primarily in some single
subject, whereas the things which he has said produce it are not found
primarily in any single subject, but each in a separate one. If so,
clearly that term could not be the product of these things: for the
whole is bound to be in the same things wherein its parts are, so
that the whole will then be found primarily not in one subject only,
but in a number of them. If, on the other hand, both parts and whole
are found primarily in some single subject, see if that medium is
not the same, but one thing in the case of the whole and another in
that of the parts. Again, see whether the parts perish together with
the whole: for it ought to happen, vice versa, that the whole perishes
when the parts perish; when the whole perishes, there is no necessity
that the parts should perish too. Or again, see if the whole be good
or evil, and the parts neither, or, vice versa, if the parts be good
or evil and the whole neither. For it is impossible either for a neutral
thing to produce something good or bad, or for things good or bad
to produce a neutral thing. Or again, see if the one thing is more
distinctly good than the other is evil, and yet the product be no
more good than evil, e.g. suppose shamelessness be defined as 'the
product of courage and false opinion': here the goodness of courage
exceeds the evil of false opinion; accordingly the product of these
ought to have corresponded to this excess, and to be either good without
qualification, or at least more good than evil. Or it may be that
this does not necessarily follow, unless each be in itself good or
bad; for many things that are productive are not good in themselves,
but only in combination; or, per contra, they are good taken singly,
and bad or neutral in combination. What has just been said is most
clearly illustrated in the case of things that make for health or
sickness; for some drugs are such that each taken alone is good, but
if they are both administered in a mixture, bad. 

Again, see whether the whole, as produced from a better and worse,
fails to be worse than the better and better than the worse element.
This again, however, need not necessarily be the case, unless the
elements compounded be in themselves good; if they are not, the whole
may very well not be good, as in the cases just instanced.

Moreover, see if the whole be synonymous with one of the elements:
for it ought not to be, any more than in the case of syllables: for
the syllable is not synonymous with any of the letters of which it
is made up. 

Moreover, see if he has failed to state the manner of their composition:
for the mere mention of its elements is not enough to make the thing
intelligible. For the essence of any compound thing is not merely
that it is a product of so-and-so, but that it is a product of them
compounded in such and such a way, just as in the case of a house:
for here the materials do not make a house irrespective of the way
they are put together. 

If a man has defined an object as 'A+B', the first thing to be said
is that 'A+B' means the same either as 'A and B', or as the 'product
of A and B.' for 'honey+water' means either the honey and the water,
or the 'drink made of honey and water'. If, then, he admits that 'A+B'
is + B' is the same as either of these two things, the same criticisms
will apply as have already been given for meeting each of them. Moreover,
distinguish between the different senses in which one thing may be
said to be '+' another, and see if there is none of them in which
A could be said to exist '+ B.' Thus e.g. supposing the expression
to mean that they exist either in some identical thing capable of
containing them (as e.g. justice and courage are found in the soul),
or else in the same place or in the same time, and if this be in no
way true of the A and B in question, clearly the definition rendered
could not hold of anything, as there is no possible way in which A
can exist B'. If, however, among the various senses above distinguished,
it be true that A and B are each found in the same time as the other,
look and see if possibly the two are not used in the same relation.
Thus e.g. suppose courage to have been defined as 'daring with right
reasoning': here it is possible that the person exhibits daring in
robbery, and right reasoning in regard to the means of health: but
he may have 'the former quality+the latter' at the same time, and
not as yet be courageous! Moreover, even though both be used in the
same relation as well, e.g. in relation to medical treatment (for
a man may exhibit both daring and right reasoning in respect of medical
treatment), still, none the less, not even this combination of 'the
one+the other 'makes him 'courageous'. For the two must not relate
to any casual object that is the same, any more than each to a different
object; rather, they must relate to the function of courage, e.g.
meeting the perils of war, or whatever is more properly speaking its
function than this. 

Some definitions rendered in this form fail to come under the aforesaid
division at all, e.g. a definition of anger as 'pain with a consciousness
of being slighted'. For what this means to say is that it is because
of a consciousness of this sort that the pain occurs; but to occur
'because of' a thing is not the same as to occur '+ a thing' in any
of its aforesaid senses. 


Part 14

Again, if he have described the whole compounded as the 'composition'
of these things (e.g. 'a living creature' as a 'composition of soul
and body'), first of all see whether he has omitted to state the kind
of composition, as (e.g.) in a definition of 'flesh' or 'bone' as
the 'composition of fire, earth, and air'. For it is not enough to
say it is a composition, but you should also go on to define the kind
of composition: for these things do not form flesh irrespective of
the manner of their composition, but when compounded in one way they
form flesh, when in another, bone. It appears, moreover, that neither
of the aforesaid substances is the same as a 'composition' at all:
for a composition always has a decomposition as its contrary, whereas
neither of the aforesaid has any contrary. Moreover, if it is equally
probable that every compound is a composition or else that none is,
and every kind of living creature, though a compound, is never a composition,
then no other compound could be a composition either. 

Again, if in the nature of a thing two contraries are equally liable
to occur, and the thing has been defined through the one, clearly
it has not been defined; else there will be more than one definition
of the same thing; for how is it any more a definition to define it
through this one than through the other, seeing that both alike are
naturally liable to occur in it? Such is the definition of the soul,
if defined as a substance capable of receiving knowledge: for it has
a like capacity for receiving ignorance. 

Also, even when one cannot attack the definition as a whole for lack
of acquaintance with the whole, one should attack some part of it,
if one knows that part and sees it to be incorrectly rendered: for
if the part be demolished, so too is the whole definition. Where,
again, a definition is obscure, one should first of all correct and
reshape it in order to make some part of it clear and get a handle
for attack, and then proceed to examine it. For the answerer is bound
either to accept the sense as taken by the questioner, or else himself
to explain clearly whatever it is that his definition means. Moreover,
just as in the assemblies the ordinary practice is to move an emendation
of the existing law and, if the emendation is better, they repeal
the existing law, so one ought to do in the case of definitions as
well: one ought oneself to propose a second definition: for if it
is seen to be better, and more indicative of the object defined, clearly
the definition already laid down will have been demolished, on the
principle that there cannot be more than one definition of the same
thing. 

In combating definitions it is always one of the chief elementary
principles to take by oneself a happy shot at a definition of the
object before one, or to adopt some correctly expressed definition.
For one is bound, with the model (as it were) before one's eyes, to
discern both any shortcoming in any features that the definition ought
to have, and also any superfluous addition, so that one is better
supplied with lines of attack. 

As to definitions, then, let so much suffice. 


BOOK VII

Part 1 

Whether two things are 'the same' or 'different', in the most literal
of the meanings ascribed to 'sameness' (and we said' that 'the same'
applies in the most literal sense to what is numerically one), may
be examined in the light of their inflexions and coordinates and opposites.
For if justice be the same as courage, then too the just man is the
same as the brave man, and 'justly' is the same as 'bravely'. Likewise,
too, in the case of their opposites: for if two things be the same,
their opposites also will be the same, in any of the recognized forms
of opposition. For it is the same thing to take the opposite of the
one or that of the other, seeing that they are the same. Again it
may be examined in the light of those things which tend to produce
or to destroy the things in question of their formation and destruction,
and in general of any thing that is related in like manner to each.
For where things are absolutely the same, their formations and destructions
also are the same, and so are the things that tend to produce or to
destroy them. Look and see also, in a case where one of two things
is said to be something or other in a superlative degree, if the other
of these alleged identical things can also be described by a superlative
in the same respect. Thus Xenocrates argues that the happy life and
the good life are the same, seeing that of all forms of life the good
life is the most desirable and so also is the happy life: for 'the
most desirable' and the greatest' apply but to one thing.' Likewise
also in other cases of the kind. Each, however, of the two things
termed 'greatest' or most desirable' must be numerically one: otherwise
no proof will have been given that they are the same; for it does
not follow because Peloponnesians and Spartans are the bravest of
the Greeks, that Peloponnesians are the same as Spartans, seeing that
'Peloponnesian' is not any one person nor yet 'Spartan'; it only follows
that the one must be included under the other as 'Spartans' are under
'Peloponnesians': for otherwise, if the one class be not included
under the other, each will be better than the other. For then the
Peloponnesians are bound to be better than the Spartans, seeing that
the one class is not included under the other; for they are better
than anybody else. Likewise also the Spartans must perforce be better
than the Peloponnesians; for they too are better than anybody else;
each then is better than the other! Clearly therefore what is styled
'best' and 'greatest' must be a single thing, if it is to be proved
to be 'the same' as another. This also is why Xenocrates fails to
prove his case: for the happy life is not numerically single, nor
yet the good life, so that it does not follow that, because they are
both the most desirable, they are therefore the same, but only that
the one falls under the other. 

Again, look and see if, supposing the one to be the same as something,
the other also is the same as it: for if they be not both the same
as the same thing, clearly neither are they the same as one another.

Moreover, examine them in the light of their accidents or of the things
of which they are accidents: for any accident belonging to the one
must belong also to the other, and if the one belong to anything as
an accident, so must the other also. If in any of these respects there
is a discrepancy, clearly they are not the same. 

See further whether, instead of both being found in one class of predicates,
the one signifies a quality and the other a quantity or relation.
Again, see if the genus of each be not the same, the one being 'good'
and the other evil', or the one being 'virtue' and the other 'knowledge':
or see if, though the genus is the same, the differentiae predicted
of either be not the same, the one (e.g.) being distinguished as a
'speculative' science, the other as a 'practical' science. Likewise
also in other cases. 

Moreover, from the point of view of 'degrees', see if the one admits
an increase of degree but not the other, or if though both admit it,
they do not admit it at the same time; just as it is not the case
that a man desires intercourse more intensely, the more intensely
he is in love, so that love and the desire for intercourse are not
the same. 

Moreover, examine them by means of an addition, and see whether the
addition of each to the same thing fails to make the same whole; or
if the subtraction of the same thing from each leaves a different
remainder. Suppose (e.g.) that he has declared 'double a half' to
be the same as 'a multiple of a half': then, subtracting the words
'a half' from each, the remainders ought to have signified the same
thing: but they do not; for 'double' and 'a multiple of' do not signify
the same thing. 

Inquire also not only if some impossible consequence results directly
from the statement made, that A and B are the same, but also whether
it is possible for a supposition to bring it about; as happens to
those who assert that 'empty' is the same as 'full of air': for clearly
if the air be exhausted, the vessel will not be less but more empty,
though it will no longer be full of air. So that by a supposition,
which may be true or may be false (it makes no difference which),
the one character is annulled and not the other, showing that they
are not the same. 

Speaking generally, one ought to be on the look-out for any discrepancy
anywhere in any sort of predicate of each term, and in the things
of which they are predicated. For all that is predicated of the one
should be predicated also of the other, and of whatever the one is
a predicate, the other should be a predicate of it as well.

Moreover, as 'sameness' is a term used in many senses, see whether
things that are the same in one way are the same also in a different
way. For there is either no necessity or even no possibility that
things that are the same specifically or generically should be numerically
the same, and it is with the question whether they are or are not
the same in that sense that we are concerned. 

Moreover, see whether the one can exist without the other; for, if
so, they could not be the same. 


Part 2

Such is the number of the commonplace rules that relate to 'sameness'.
It is clear from what has been said that all the destructive commonplaces
relating to sameness are useful also in questions of definition, as
was said before:' for if what is signified by the term and by the
expression be not the same, clearly the expression rendered could
not be a definition. None of the constructive commonplaces, on the
other hand, helps in the matter of definition; for it is not enough
to show the sameness of content between the expression and the term,
in order to establish that the former is a definition, but a definition
must have also all the other characters already announced.


Part 3

This then is the way, and these the arguments, whereby the attempt
to demolish a definition should always be made. If, on the other hand,
we desire to establish one, the first thing to observe is that few
if any who engage in discussion arrive at a definition by reasoning:
they always assume something of the kind as their starting points-both
in geometry and in arithmetic and the other studies of that kind.
In the second place, to say accurately what a definition is, and how
it should be given, belongs to another inquiry. At present it concerns
us only so far as is required for our present purpose, and accordingly
we need only make the bare statement that to reason to a thing's definition
and essence is quite possible. For if a definition is an expression
signifying the essence of the thing and the predicates contained therein
ought also to be the only ones which are predicated of the thing in
the category of essence; and genera and differentiae are so predicated
in that category: it is obvious that if one were to get an admission
that so and so are the only attributes predicated in that category,
the expression containing so and so would of necessity be a definition;
for it is impossible that anything else should be a definition, seeing
that there is not anything else predicated of the thing in the category
of essence. 

That a definition may thus be reached by a process of reasoning is
obvious. The means whereby it should be established have been more
precisely defined elsewhere, but for the purposes of the inquiry now
before us the same commonplace rules serve. For we have to examine
into the contraries and other opposites of the thing, surveying the
expressions used both as wholes and in detail: for if the opposite
definition defines that opposite term, the definition given must of
necessity be that of the term before us. Seeing, however, that contraries
may be conjoined in more than one way, we have to select from those
contraries the one whose contrary definition seems most obvious. The
expressions, then, have to be examined each as a whole in the way
we have said, and also in detail as follows. First of all, see that
the genus rendered is correctly rendered; for if the contrary thing
be found in the contrary genus to that stated in the definition, and
the thing before you is not in that same genus, then it would clearly
be in the contrary genus: for contraries must of necessity be either
in the same genus or in contrary genera. The differentiae, too, that
are predicated of contraries we expect to be contrary, e.g. those
of white and black, for the one tends to pierce the vision, while
the other tends to compress it. So that if contrary differentiae to
those in the definition are predicated of the contrary term, then
those rendered in the definition would be predicated of the term before
us. Seeing, then, that both the genus and the differentiae have been
rightly rendered, clearly the expression given must be the right definition.
It might be replied that there is no necessity why contrary differentiae
should be predicated of contraries, unless the contraries be found
within the same genus: of things whose genera are themselves contraries
it may very well be that the same differentia is used of both, e.g.
of justice and injustice; for the one is a virtue and the other a
vice of the soul: 'of the soul', therefore, is the differentia in
both cases, seeing that the body as well has its virtue and vice.
But this much at least is true, that the differentiae of contraries
are either contrary or else the same. If, then, the contrary differentia
to that given be predicated of the contrary term and not of the one
in hand, clearly the differentia stated must be predicated of the
latter. Speaking generally, seeing that the definition consists of
genus and differentiae, if the definition of the contrary term be
apparent, the definition of the term before you will be apparent also:
for since its contrary is found either in the same genus or in the
contrary genus, and likewise also the differentiae predicated of opposites
are either contrary to, or the same as, each other, clearly of the
term before you there will be predicated either the same genus as
of its contrary, while, of its differentiae, either all are contrary
to those of its contrary, or at least some of them are so while the
rest remain the same; or, vice versa, the differentiae will be the
same and the genera contrary; or both genera and differentiae will
be contrary. And that is all; for that both should be the same is
not possible; else contraries will have the same definition.

Moreover, look at it from the point of view of its inflexions and
coordinates. For genera and definitions are bound to correspond in
either case. Thus if forgetfulness be the loss of knowledge, to forget
is to lose knowledge, and to have forgotten is to have lost knowledge.
If, then, any one whatever of these is agreed to, the others must
of necessity be agreed to as well. Likewise, also, if destruction
is the decomposition of the thing's essence, then to be destroyed
is to have its essence decomposed, and 'destructively' means 'in such
a way as to decompose its essence'; if again 'destructive' means 'apt
to decompose something's essence', then also 'destruction' means 'the
decomposition of its essence'. Likewise also with the rest: an admission
of any one of them whatever, and all the rest are admitted too.

Moreover, look at it from the point of view of things that stand in
relations that are like each other. For if 'healthy' means 'productive
of health', 'vigorous' too will mean 'productive of vigour', and 'useful'
will mean 'productive of good.' For each of these things is related
in like manner to its own peculiar end, so that if one of them is
defined as 'productive of' that end, this will also be the definition
of each of the rest as well. 

Moreover, look at it from the point of and like degrees, in all the
ways in which it is possible to establish a result by comparing two
and two together. Thus if A defines a better than B defines and B
is a definition of so too is A of a. Further, if A's claim to define
a is like B's to define B, and B defines B, then A too defines a.
This examination from the point of view of greater degrees is of no
use when a single definition is compared with two things, or two definitions
with one thing; for there cannot possibly be one definition of two
things or two of the same thing. 


Part 4

The most handy of all the commonplace arguments are those just mentioned
and those from co-ordinates and inflexions, and these therefore are
those which it is most important to master and to have ready to hand:
for they are the most useful on the greatest number of occasions.
Of the rest, too, the most important are those of most general application:
for these are the most effective, e.g. that you should examine the
individual cases, and then look to see in the case of their various
species whether the definition applies. For the species is synonymous
with its individuals. This sort of inquiry is of service against those
who assume the existence of Ideas, as has been said before.' Moreover
see if a man has used a term metaphorically, or predicated it of itself
as though it were something different. So too if any other of the
commonplace rules is of general application and effective, it should
be employed. 


Part 5

That it is more difficult to establish than to overthrow a definition,
is obvious from considerations presently to be urged. For to see for
oneself, and to secure from those whom one is questioning, an admission
of premisses of this sort is no simple matter, e.g. that of the elements
of the definition rendered the one is genus and the other differentia,
and that only the genus and differentiae are predicated in the category
of essence. Yet without these premisses it is impossible to reason
to a definition; for if any other things as well are predicated of
the thing in the category of essence, there is no telling whether
the formula stated or some other one is its definition, for a definition
is an expression indicating the essence of a thing. The point is clear
also from the following: It is easier to draw one conclusion than
many. Now in demolishing a definition it is sufficient to argue against
one point only (for if we have overthrown any single point whatsoever,
we shall have demolished the definition); whereas in establishing
a definition, one is bound to bring people to the view that everything
contained in the definition is attributable. Moreover, in establishing
a case, the reasoning brought forward must be universal: for the definition
put forward must be predicated of everything of which the term is
predicated, and must moreover be convertible, if the definition rendered
is to be peculiar to the subject. In overthrowing a view, on the other
hand, there is no longer any necessity to show one's point universally:
for it is enough to show that the formula is untrue of any one of
the things embraced under the term. 

Further, even supposing it should be necessary to overthrow something
by a universal proposition, not even so is there any need to prove
the converse of the proposition in the process of overthrowing the
definition. For merely to show that the definition fails to be predicated
of every one of the things of which the term is predicated, is enough
to overthrow it universally: and there is no need to prove the converse
of this in order to show that the term is predicated of things of
which the expression is not predicated. Moreover, even if it applies
to everything embraced under the term, but not to it alone, the definition
is thereby demolished. 

The case stands likewise in regard to the property and genus of a
term also. For in both cases it is easier to overthrow than to establish.
As regards the property this is clear from what has been said: for
as a rule the property is rendered in a complex phrase, so that to
overthrow it, it is only necessary to demolish one of the terms used,
whereas to establish it is necessary to reason to them all. Then,
too, nearly all the other rules that apply to the definition will
apply also to the property of a thing. For in establishing a property
one has to show that it is true of everything included under the term
in question, whereas to overthrow one it is enough to show in a single
case only that it fails to belong: further, even if it belongs to
everything falling under the term, but not to that only, it is overthrown
in this case as well, as was explained in the case of the definition.
In regard to the genus, it is clear that you are bound to establish
it in one way only, viz. by showing that it belongs in every case,
while of overthrowing it there are two ways: for if it has been shown
that it belongs either never or not in a certain case, the original
statement has been demolished. Moreover, in establishing a genus it
is not enough to show that it belongs, but also that it belongs as
genus has to be shown; whereas in overthrowing it, it is enough to
show its failure to belong either in some particular case or in every
case. It appears, in fact, as though, just as in other things to destroy
is easier than to create, so in these matters too to overthrow is
easier than to establish. 

In the case of an accidental attribute the universal proposition is
easier to overthrow than to establish; for to establish it, one has
to show that it belongs in every case, whereas to overthrow it, it
is enough to show that it does not belong in one single case. The
particular proposition is, on the contrary, easier to establish than
to overthrow: for to establish it, it is enough to show that it belongs
in a particular instance, whereas to overthrow it, it has to be shown
that it never belongs at all. 

It is clear also that the easiest thing of all is to overthrow a definition.
For on account of the number of statements involved we are presented
in the definition with the greatest number of points for attack, and
the more plentiful the material, the quicker an argument comes: for
there is more likelihood of a mistake occurring in a large than in
a small number of things. Moreover, the other rules too may be used
as means for attacking a definition: for if either the formula be
not peculiar, or the genus rendered be the wrong one, or something
included in the formula fail to belong, the definition is thereby
demolished. On the other hand, against the others we cannot bring
all of the arguments drawn from definitions, nor yet of the rest:
for only those relating to accidental attributes apply generally to
all the aforesaid kinds of attribute. For while each of the aforesaid
kinds of attribute must belong to the thing in question, yet the genus
may very well not belong as a property without as yet being thereby
demolished. Likewise also the property need not belong as a genus,
nor the accident as a genus or property, so long as they do belong.
So that it is impossible to use one set as a basis of attack upon
the other except in the case of definition. Clearly, then, it is the
easiest of all things to demolish a definition, while to establish
one is the hardest. For there one both has to establish all those
other points by reasoning (i.e. that the attributes stated belong,
and that the genus rendered is the true genus, and that the formula
is peculiar to the term), and moreover, besides this, that the formula
indicates the essence of the thing; and this has to be done correctly.

Of the rest, the property is most nearly of this kind: for it is easier
to demolish, because as a rule it contains several terms; while it
is the hardest to establish, both because of the number of things
that people must be brought to accept, and, besides this, because
it belongs to its subject alone and is predicated convertibly with
its subject. 

The easiest thing of all to establish is an accidental predicate:
for in other cases one has to show not only that the predicate belongs,
but also that it belongs in such and such a particular way: whereas
in the case of the accident it is enough to show merely that it belongs.
On the other hand, an accidental predicate is the hardest thing to
overthrow, because it affords the least material: for in stating accident
a man does not add how the predicate belongs; and accordingly, while
in other cases it is possible to demolish what is said in two ways,
by showing either that the predicate does not belong, or that it does
not belong in the particular way stated, in the case of an accidental
predicate the only way to demolish it is to show that it does not
belong at all. 

The commonplace arguments through which we shall be well supplied
with lines of argument with regard to our several problems have now
been enumerated at about sufficient length. 


BOOK VIII

Part 1 

Next there fall to be discussed the problems of arrangement and method
in pitting questions. Any one who intends to frame questions must,
first of all, select the ground from which he should make his attack;
secondly, he must frame them and arrange them one by one to himself;
thirdly and lastly, he must proceed actually to put them to the other
party. Now so far as the selection of his ground is concerned the
problem is one alike for the philosopher and the dialectician; but
how to go on to arrange his points and frame his questions concerns
the dialectician only: for in every problem of that kind a reference
to another party is involved. Not so with the philosopher, and the
man who is investigating by himself: the premisses of his reasoning,
although true and familiar, may be refused by the answerer because
they lie too near the original statement and so he foresees what will
follow if he grants them: but for this the philosopher does not care.
Nay, he may possibly be even anxious to secure axioms as familiar
and as near to the question in hand as possible: for these are the
bases on which scientific reasonings are built up. 

The sources from which one's commonplace arguments should be drawn
have already been described:' we have now to discuss the arrangement
and formation of questions and first to distinguish the premisses,
other than the necessary premisses, which have to be adopted. By necessary
premisses are meant those through which the actual reasoning is constructed.
Those which are secured other than these are of four kinds; they serve
either inductively to secure the universal premiss being granted,
or to lend weight to the argument, or to conceal the conclusion, or
to render the argument more clear. Beside these there is no other
premiss which need be secured: these are the ones whereby you should
try to multiply and formulate your questions. Those which are used
to conceal the conclusion serve a controversial purpose only; but
inasmuch as an undertaking of this sort is always conducted against
another person, we are obliged to employ them as well. 

The necessary premisses through which the reasoning is effected, ought
not to be propounded directly in so many words. Rather one should
soar as far aloof from them as possible. Thus if one desires to secure
an admission that the knowledge of contraries is one, one should ask
him to admit it not of contraries, but of opposites: for, if he grants
this, one will then argue that the knowledge of contraries is also
the same, seeing that contraries are opposites; if he does not, one
should secure the admission by induction, by formulating a proposition
to that effect in the case of some particular pair of contraries.
For one must secure the necessary premisses either by reasoning or
by induction, or else partly by one and partly by the other, although
any propositions which are too obvious to be denied may be formulated
in so many words. This is because the coming conclusion is less easily
discerned at the greater distance and in the process of induction,
while at the same time, even if one cannot reach the required premisses
in this way, it is still open to one to formulate them in so many
words. The premisses, other than these, that were mentioned above,
must be secured with a view to the latter. The way to employ them
respectively is as follows: Induction should proceed from individual
cases to the universal and from the known to the unknown; and the
objects of perception are better known, to most people if not invariably.
Concealment of one's plan is obtained by securing through prosyllogisms
the premisses through which the proof of the original proposition
is going to be constructed-and as many of them as possible. This is
likely to be effected by making syllogisms to prove not only the necessary
premisses but also some of those which are required to establish them.
Moreover, do not state the conclusions of these premisses but draw
them later one after another; for this is likely to keep the answerer
at the greatest possible distance from the original proposition. Speaking
generally, a man who desires to get information by a concealed method
should so put his questions that when he has put his whole argument
and has stated the conclusion, people still ask 'Well, but why is
that?' This result will be secured best of all by the method above
described: for if one states only the final conclusion, it is unclear
how it comes about; for the answerer does not foresee on what grounds
it is based, because the previous syllogisms have not been made articulate
to him: while the final syllogism, showing the conclusion, is likely
to be kept least articulate if we lay down not the secured propositions
on which it is based, but only the grounds on which we reason to them.

It is a useful rule, too, not to secure the admissions claimed as
the bases of the syllogisms in their proper order, but alternately
those that conduce to one conclusion and those that conduce to another;
for, if those which go together are set side by side, the conclusion
that will result from them is more obvious in advance. 

One should also, wherever possible, secure the universal premiss by
a definition relating not to the precise terms themselves but to their
co-ordinates; for people deceive themselves, whenever the definition
is taken in regard to a co-ordinate, into thinking that they are not
making the admission universally. An instance would be, supposing
one had to secure the admission that the angry man desires vengeance
on account of an apparent slight, and were to secure this, that 'anger'
is a desire for vengeance on account of an apparent slight: for, clearly,
if this were secured, we should have universally what we intend. If,
on the other hand, people formulate propositions relating to the actual
terms themselves, they often find that the answerer refuses to grant
them because on the actual term itself he is readier with his objection,
e.g. that the 'angry man' does not desire vengeance, because we become
angry with our parents, but we do not desire vengeance on them. Very
likely the objection is not valid; for upon some people it is vengeance
enough to cause them pain and make them sorry; but still it gives
a certain plausibility and air of reasonableness to the denial of
the proposition. In the case, however, of the definition of 'anger'
it is not so easy to find an objection. 

Moreover, formulate your proposition as though you did so not for
its own sake, but in order to get at something else: for people are
shy of granting what an opponent's case really requires. Speaking
generally, a questioner should leave it as far as possible doubtful
whether he wishes to secure an admission of his proposition or of
its opposite: for if it be uncertain what their opponent's argument
requires, people are more ready to say what they themselves think.

Moreover, try to secure admissions by means of likeness: for such
admissions are plausible, and the universal involved is less patent;
e.g. make the other person admit that as knowledge and ignorance of
contraries is the same, so too perception of contraries is the same;
or vice versa, that since the perception is the same, so is the knowledge
also. This argument resembles induction, but is not the same thing;
for in induction it is the universal whose admission is secured from
the particulars, whereas in arguments from likeness, what is secured
is not the universal under which all the like cases fall.

It is a good rule also, occasionally to bring an objection against
oneself: for answerers are put off their guard against those who appear
to be arguing impartially. It is useful too, to add that 'So and so
is generally held or commonly said'; for people are shy of upsetting
the received opinion unless they have some positive objection to urge:
and at the same time they are cautious about upsetting such things
because they themselves too find them useful. Moreover, do not be
insistent, even though you really require the point: for insistence
always arouses the more opposition. Further, formulate your premiss
as though it were a mere illustration: for people admit the more readily
a proposition made to serve some other purpose, and not required on
its own account. Moreover, do not formulate the very proposition you
need to secure, but rather something from which that necessarily follows:
for people are more willing to admit the latter, because it is not
so clear from this what the result will be, and if the one has been
secured, the other has been secured also. Again, one should put last
the point which one most wishes to have conceded; for people are specially
inclined to deny the first questions put to them, because most people
in asking questions put first the points which they are most eager
to secure. On the other hand, in dealing with some people propositions
of this sort should be put forward first: for ill-tempered men admit
most readily what comes first, unless the conclusion that will result
actually stares them in the face, while at the close of an argument
they show their ill-temper. Likewise also with those who consider
themselves smart at answering: for when they have admitted most of
what you want they finally talk clap-trap to the effect that the conclusion
does not follow from their admissions: yet they say 'Yes' readily,
confident in their own character, and imagining that they cannot suffer
any reverse. Moreover, it is well to expand the argument and insert
things that it does not require at all, as do those who draw false
geometrical figures: for in the multitude of details the whereabouts
of the fallacy is obscured. For this reason also a questioner sometimes
evades observation as he adds in a corner what, if he formulated it
by itself, would not be granted. 

For concealment, then, the rules which should be followed are the
above. Ornament is attained by induction and distinction of things
closely akin. What sort of process induction is obvious: as for distinction,
an instance of the kind of thing meant is the distinction of one form
of knowledge as better than another by being either more accurate,
or concerned with better objects; or the distinction of sciences into
speculative, practical, and productive. For everything of this kind
lends additional ornament to the argument, though there is no necessity
to say them, so far as the conclusion goes. 

For clearness, examples and comparisons should be adduced, and let
the illustrations be relevant and drawn from things that we know,
as in Homer and not as in Choerilus; for then the proposition is likely
to become clearer. 


Part 2

In dialectics, syllogism should be employed in reasoning against dialecticians
rather than against the crowd: induction, on the other hand, is most
useful against the crowd. This point has been treated previously as
well.' In induction, it is possible in some cases to ask the question
in its universal form, but in others this is not easy, because there
is no established general term that covers all the resemblances: in
this case, when people need to secure the universal, they use the
phrase 'in all cases of this sort'. But it is one of the very hardest
things to distinguish which of the things adduced are 'of this sort',
and which are not: and in this connexion people often throw dust in
each others' eyes in their discussion, the one party asserting the
likeness of things that are not alike, and the other disputing the
likeness of things that are. One ought, therefore, to try oneself
to coin a word to cover all things of the given sort, so as to leave
no opportunity either to the answerer to dispute, and say that the
thing advanced does not answer to a like description, or to the questioner
to suggest falsely that it does answer to a like description, for
many things appear to answer to like descriptions that do not really
do so. 

If one has made an induction on the strength of several cases and
yet the answerer refuses to grant the universal proposition, then
it is fair to demand his objection. But until one has oneself stated
in what cases it is so, it is not fair to demand that he shall say
in what cases it is not so: for one should make the induction first,
and then demand the objection. One ought, moreover, to claim that
the objections should not be brought in reference to the actual subject
of the proposition, unless that subject happen to be the one and only
thing of the kind, as for instance two is the one prime number among
the even numbers: for, unless he can say that this subject is unique
of its kind, the objector ought to make his objection in regard to
some other. People sometimes object to a universal proposition, and
bring their objection not in regard to the thing itself, but in regard
to some homonym of it: thus they argue that a man can very well have
a colour or a foot or a hand other than his own, for a painter may
have a colour that is not his own, and a cook may have a foot that
is not his own. To meet them, therefore, you should draw the distinction
before putting your question in such cases: for so long as the ambiguity
remains undetected, so long will the objection to the proposition
be deemed valid. If, however, he checks the series of questions by
an objection in regard not to some homonym, but to the actual thing
asserted, the questioner should withdraw the point objected to, and
form the remainder into a universal proposition, until he secures
what he requires; e.g. in the case of forgetfulness and having forgotten:
for people refuse to admit that the man who has lost his knowledge
of a thing has forgotten it, because if the thing alters, he has lost
knowledge of it, but he has not forgotten it. Accordingly the thing
to do is to withdraw the part objected to, and assert the remainder,
e.g. that if a person have lost knowledge of a thing while it still
remains, he then has forgotten it. One should similarly treat those
who object to the statement that 'the greater the good, the greater
the evil that is its opposite': for they allege that health, which
is a less good thing than vigour, has a greater evil as its opposite:
for disease is a greater evil than debility. In this case too, therefore,
we have to withdraw the point objected to; for when it has been withdrawn,
the man is more likely to admit the proposition, e.g. that 'the greater
good has the greater evil as its opposite, unless the one good involves
the other as well', as vigour involves health. This should be done
not only when he formulates an objection, but also if, without so
doing, he refuses to admit the point because he foresees something
of the kind: for if the point objected to be withdrawn, he will be
forced to admit the proposition because he cannot foresee in the rest
of it any case where it does not hold true: if he refuse to admit
it, then when asked for an objection he certainly will be unable to
render one. Propositions that are partly false and partly true are
of this type: for in the case of these it is possible by withdrawing
a part to leave the rest true. If, however, you formulate the proposition
on the strength of many cases and he has no objection to bring, you
may claim that he shall admit it: for a premiss is valid in dialectics
which thus holds in several instances and to which no objection is
forthcoming. 

Whenever it is possible to reason to the same conclusion either through
or without a reduction per impossibile, if one is demonstrating and
not arguing dialectically it makes no difference which method of reasoning
be adopted, but in argument with another reasoning per impossibile
should be avoided. For where one has reasoned without the reduction
per impossibile, no dispute can arise; if, on the other hand, one
does reason to an impossible conclusion, unless its falsehood is too
plainly manifest, people deny that it is impossible, so that the questioners
do not get what they want. 

One should put forward all propositions that hold true of several
cases, and to which either no objection whatever appears or at least
not any on the surface: for when people cannot see any case in which
it is not so, they admit it for true. 

The conclusion should not be put in the form of a question; if it
be, and the man shakes his head, it looks as if the reasoning had
failed. For often, even if it be not put as a question but advanced
as a consequence, people deny it, and then those who do not see that
it follows upon the previous admissions do not realize that those
who deny it have been refuted: when, then, the one man merely asks
it as a question without even saying that it so follows, and the other
denies it, it looks altogether as if the reasoning had failed.

Not every universal question can form a dialectical proposition as
ordinarily understood, e.g. 'What is man?' or 'How many meanings has
"the good"?' For a dialectical premiss must be of a form to which
it is possible to reply 'Yes' or 'No', whereas to the aforesaid it
is not possible. For this reason questions of this kind are not dialectical
unless the questioner himself draws distinctions or divisions before
expressing them, e.g. 'Good means this, or this, does it not?' For
questions of this sort are easily answered by a Yes or a No. Hence
one should endeavour to formulate propositions of this kind in this
form. It is at the same time also perhaps fair to ask the other man
how many meanings of 'the good' there are, whenever you have yourself
distinguished and formulated them, and he will not admit them at all.

Any one who keeps on asking one thing for a long time is a bad inquirer.
For if he does so though the person questioned keeps on answering
the questions, clearly he asks a large number of questions, or else
asks the same question a large number of times: in the one case he
merely babbles, in the other he fails to reason: for reasoning always
consists of a small number of premisses. If, on the other hand, he
does it because the person questioned does not answer the questions,
he is at fault in not taking him to task or breaking off the discussion.


Part 3

There are certain hypotheses upon which it is at once difficult to
bring, and easy to stand up to, an argument. Such (e.g.) are those
things which stand first and those which stand last in the order of
nature. For the former require definition, while the latter have to
be arrived at through many steps if one wishes to secure a continuous
proof from first principles, or else all discussion about them wears
the air of mere sophistry: for to prove anything is impossible unless
one begins with the appropriate principles, and connects inference
with inference till the last are reached. Now to define first principles
is just what answerers do not care to do, nor do they pay any attention
if the questioner makes a definition: and yet until it is clear what
it is that is proposed, it is not easy to discuss it. This sort of
thing happens particularly in the case of the first principles: for
while the other propositions are shown through these, these cannot
be shown through anything else: we are obliged to understand every
item of that sort by a definition. The inferences, too, that lie too
close to the first principle are hard to treat in argument: for it
is not possible to bring many arguments in regard to them, because
of the small number of those steps, between the conclusion and the
principle, whereby the succeeding propositions have to be shown. The
hardest, however, of all definitions to treat in argument are those
that employ terms about which, in the first place, it is uncertain
whether they are used in one sense or several, and, further, whether
they are used literally or metaphorically by the definer. For because
of their obscurity, it is impossible to argue upon such terms; and
because of the impossibility of saying whether this obscurity is due
to their being used metaphorically, it is impossible to refute them.

In general, it is safe to suppose that, whenever any problem proves
intractable, it either needs definition or else bears either several
senses, or a metaphorical sense, or it is not far removed from the
first principles; or else the reason is that we have yet to discover
in the first place just this-in which of the aforesaid directions
the source of our difficulty lies: when we have made this clear, then
obviously our business must be either to define or to distinguish,
or to supply the intermediate premisses: for it is through these that
the final conclusions are shown. 

It often happens that a difficulty is found in discussing or arguing
a given position because the definition has not been correctly rendered:
e.g. 'Has one thing one contrary or many?': here when the term 'contraries'
has been properly defined, it is easy to bring people to see whether
it is possible for the same thing to have several contraries or not:
in the same way also with other terms requiring definition. It appears
also in mathematics that the difficulty in using a figure is sometimes
due to a defect in definition; e.g. in proving that the line which
cuts the plane parallel to one side divides similarly both the line
which it cuts and the area; whereas if the definition be given, the
fact asserted becomes immediately clear: for the areas have the same
fraction subtracted from them as have the sides: and this is the definition
of 'the same ratio'. The most primary of the elementary principles
are without exception very easy to show, if the definitions involved,
e.g. the nature of a line or of a circle, be laid down; only the arguments
that can be brought in regard to each of them are not many, because
there are not many intermediate steps. If, on the other hand, the
definition of the starting-points be not laid down, to show them is
difficult and may even prove quite impossible. The case of the significance
of verbal expressions is like that of these mathematical conceptions.

One may be sure then, whenever a position is hard to discuss, that
one or other of the aforesaid things has happened to it. Whenever,
on the other hand, it is a harder task to argue to the point claimed,
i.e. the premiss, than to the resulting position, a doubt may arise
whether such claims should be admitted or not: for if a man is going
to refuse to admit it and claim that you shall argue to it as well,
he will be giving the signal for a harder undertaking than was originally
proposed: if, on the other hand, he grants it, he will be giving the
original thesis credence on the strength of what is less credible
than itself. If, then, it is essential not to enhance the difficulty
of the problem, he had better grant it; if, on the other hand, it
be essential to reason through premisses that are better assured,
he had better refuse. In other words, in serious inquiry he ought
not to grant it, unless he be more sure about it than about the conclusion;
whereas in a dialectical exercise he may do so if he is merely satisfied
of its truth. Clearly, then, the circumstances under which such admissions
should be claimed are different for a mere questioner and for a serious
teacher. 


Part 4

As to the formulation, then, and arrangement of one's questions, about
enough has been said. 

With regard to the giving of answers, we must first define what is
the business of a good answerer, as of a good questioner. The business
of the questioner is so to develop the argument as to make the answerer
utter the most extrvagant paradoxes that necessarily follow because
of his position: while that of the answerer is to make it appear that
it is not he who is responsible for the absurdity or paradox, but
only his position: for one may, perhaps, distinguish between the mistake
of taking up a wrong position to start with, and that of not maintaining
it properly, when once taken up. 


Part 5

Inasmuch as no rules are laid down for those who argue for the sake
of training and of examination:-and the aim of those engaged in teaching
or learning is quite different from that of those engaged in a competition;
as is the latter from that of those who discuss things together in
the spirit of inquiry: for a learner should always state what he thinks:
for no one is even trying to teach him what is false; whereas in a
competition the business of the questioner is to appear by all means
to produce an effect upon the other, while that of the answerer is
to appear unaffected by him; on the other hand, in an assembly of
disputants discussing in the spirit not of a competition but of an
examination and inquiry, there are as yet no articulate rules about
what the answerer should aim at, and what kind of things he should
and should not grant for the correct or incorrect defence of his position:-inasmuch,
then, as we have no tradition bequeathed to us by others, let us try
to say something upon the matter for ourselves. 

The thesis laid down by the answerer before facing the questioner's
argument is bound of necessity to be one that is either generally
accepted or generally rejected or else is neither: and moreover is
so accepted or rejected either absolutely or else with a restriction,
e.g. by some given person, by the speaker or by some one else. The
manner, however, of its acceptance or rejection, whatever it be, makes
no difference: for the right way to answer, i.e. to admit or to refuse
to admit what has been asked, will be the same in either case. If,
then, the statement laid down by the answerer be generally rejected,
the conclusion aimed at by the questioner is bound to be one generally
accepted, whereas if the former be generally accepted, the latter
is generally rejected: for the conclusion which the questioner tries
to draw is always the opposite of the statement laid down. If, on
the other hand, what is laid down is generally neither rejected nor
accepted, the conclusion will be of the same type as well. Now since
a man who reasons correctly demonstrates his proposed conclusion from
premisses that are more generally accepted, and more familiar, it
is clear that (1) where the view laid down by him is one that generally
is absolutely rejected, the answerer ought not to grant either what
is thus absolutely not accepted at all, or what is accepted indeed,
but accepted less generally than the questioner's conclusion. For
if the statement laid down by the answerer be generally rejected,
the conclusion aimed at by the questioner will be one that is generally
accepted, so that the premisses secured by the questioner should all
be views generally accepted, and more generally accepted than his
proposed conclusion, if the less familiar is to be inferred through
the more familiar. Consequently, if any of the questions put to him
be not of this character, the answerer should not grant them. (2)
If, on the other hand, the statement laid down by the answerer be
generally accepted without qualification, clearly the conclusion sought
by the questioner will be one generally rejected without qualification.
Accordingly, the answerer should admit all views that are generally
accepted and, of those that are not generally accepted, all that are
less generally rejected than the conclusion sought by the questioner.
For then he will probably be thought to have argued sufficiently well.
(3) Likewise, too, if the statement laid down by the answerer be neither
rejected generally nor generally accepted; for then, too, anything
that appears to be true should be granted, and, of the views not generally
accepted, any that are more generally accepted than the questioner's
conclusion; for in that case the result will be that the arguments
will be more generally accepted. If, then, the view laid down by the
answerer be one that is generally accepted or rejected without qualification,
then the views that are accepted absolutely must be taken as the standard
of comparison: whereas if the view laid down be one that is not generally
accepted or rejected, but only by the answerer, then the standard
whereby the latter must judge what is generally accepted or not, and
must grant or refuse to grant the point asked, is himself. If, again,
the answerer be defending some one else's opinion, then clearly it
will be the latter's judgement to which he must have regard in granting
or denying the various points. This is why those, too, who introduce
other's opinions, e.g. that 'good and evil are the same thing, as
Heraclitus says,' refuse to admit the impossibility of contraries
belonging at the same time to the same thing; not because they do
not themselves believe this, but because on Heraclitus' principles
one has to say so. The same thing is done also by those who take on
the defence of one another's positions; their aim being to speak as
would the man who stated the position. 


Part 6

It is clear, then, what the aims of the answerer should be, whether
the position he lays down be a view generally accepted without qualification
or accepted by some definite person. Now every question asked is bound
to involve some view that is either generally held or generally rejected
or neither, and is also bound to be either relevant to the argument
or irrelevant: if then it be a view generally accepted and irrelevant,
the answerer should grant it and remark that it is the accepted view:
if it be a view not generally accepted and irrelevant, he should grant
it but add a comment that it is not generally accepted, in order to
avoid the appearance of being a simpleton. If it be relevant and also
be generally accepted, he should admit that it is the view generally
accepted but say that it lies too close to the original proposition,
and that if it be granted the problem proposed collapses. If what
is claimed by the questioner be relevant but too generally rejected,
the answerer, while admitting that if it be granted the conclusion
sought follows, should yet protest that the proposition is too absurd
to be admitted. Suppose, again, it be a view that is neither rejected
generally nor generally accepted, then, if it be irrelevant to the
argument, it may be granted without restriction; if, however, it be
relevant, the answerer should add the comment that, if it be granted,
the original problem collapses. For then the answerer will not be
held to be personally accountable for what happens to him, if he grants
the several points with his eyes open, and also the questioner will
be able to draw his inference, seeing that all the premisses that
are more generally accepted than the conclusion are granted him. Those
who try to draw an inference from premisses more generally rejected
than the conclusion clearly do not reason correctly: hence, when men
ask these things, they ought not to be granted. 


Part 7

The questioner should be met in a like manner also in the case of
terms used obscurely, i.e. in several senses. For the answerer, if
he does not understand, is always permitted to say 'I do not understand':
he is not compelled to reply 'Yes' or 'No' to a question which may
mean different things. Clearly, then, in the first place, if what
is said be not clear, he ought not to hesitate to say that he does
not understand it; for often people encounter some difficulty from
assenting to questions that are not clearly put. If he understands
the question and yet it covers many senses, then supposing what it
says to be universally true or false, he should give it an unqualified
assent or denial: if, on the other hand, it be partly true and partly
false, he should add a comment that it bears different senses, and
also that in one it is true, in the other false: for if he leave this
distinction till later, it becomes uncertain whether originally as
well he perceived the ambiguity or not. If he does not foresee the
ambiguity, but assents to the question having in view the one sense
of the words, then, if the questioner takes it in the other sense,
he should say, 'That was not what I had in view when I admitted it;
I meant the other sense': for if a term or expression covers more
than one thing, it is easy to disagree. If, however, the question
is both clear and simple, he should answer either 'Yes' or 'No'.


Part 8

A premiss in reasoning always either is one of the constituent elements
in the reasoning, or else goes to establish one of these: (and you
can always tell when it is secured in order to establish something
else by the fact of a number of similar questions being put: for as
a rule people secure their universal by means either of induction
or of likeness):-accordingly the particular propositions should all
be admitted, if they are true and generally held. On the other hand,
against the universal one should try to bring some negative instance;
for to bring the argument to a standstill without a negative instance,
either real or apparent, shows ill-temper. If, then, a man refuses
to grant the universal when supported by many instances, although
he has no negative instance to show, he obviously shows ill-temper.
If, moreover, he cannot even attempt a counter-proof that it is not
true, far more likely is he to be thought ill-tempered-although even
counter-proof is not enough: for we often hear arguments that are
contrary to common opinions, whose solution is yet difficult, e.g.
the argument of Zeno that it is impossible to move or to traverse
the stadium;-but still, this is no reason for omitting to assert the
opposites of these views. If, then, a man refuses to admit the proposition
without having either a negative instance or some counter-argument
to bring against it, clearly he is ill-tempered: for ill-temper in
argument consists in answering in ways other than the above, so as
to wreck the reasoning. 


Part 9

Before maintaining either a thesis or a definition the answerer should
try his hand at attacking it by himself; for clearly his business
is to oppose those positions from which questioners demolish what
he has laid down. 

He should beware of maintaining a hypothesis that is generally rejected:
and this it may be in two ways: for it may be one which results in
absurd statements, e.g. suppose any one were to say that everything
is in motion or that nothing is; and also there are all those which
only a bad character would choose, and which are implicitly opposed
to men's wishes, e.g. that pleasure is the good, and that to do injustice
is better than to suffer it. For people then hate him, supposing him
to maintain them not for the sake of argument but because he really
thinks them. 


Part 10

Of all arguments that reason to a false conclusion the right solution
is to demolish the point on which the fallacy that occurs depends:
for the demolition of any random point is no solution, even though
the point demolished be false. For the argument may contain many falsehoods,
e.g. suppose some one to secure the premisses, 'He who sits, writes'
and 'Socrates is sitting': for from these it follows that 'Socrates
is writing'. Now we may demolish the proposition 'Socrates is sitting',
and still be no nearer a solution of the argument; it may be true
that the point claimed is false; but it is not on that that fallacy
of the argument depends: for supposing that any one should happen
to be sitting and not writing, it would be impossible in such a case
to apply the same solution. Accordingly, it is not this that needs
to be demolished, but rather that 'He who sits, writes': for he who
sits does not always write. He, then, who has demolished the point
on which the fallacy depends, has given the solution of the argument
completely. Any one who knows that it is on such and such a point
that the argument depends, knows the solution of it, just as in the
case of a figure falsely drawn. For it is not enough to object, even
if the point demolished be a falsehood, but the reason of the fallacy
should also be proved: for then it would be clear whether the man
makes his objection with his eyes open or not. 

There are four possible ways of preventing a man from working his
argument to a conclusion. It can be done either by demolishing the
point on which the falsehood that comes about depends, or by stating
an objection directed against the questioner: for often when a solution
has not as a matter of fact been brought, yet the questioner is rendered
thereby unable to pursue the argument any farther. Thirdly, one may
object to the questions asked: for it may happen that what the questioner
wants does not follow from the questions he has asked because he has
asked them badly, whereas if something additional be granted the conclusion
comes about. If, then, the questioner be unable to pursue his argument
farther, the objection would properly be directed against the questioner;
if he can do so, then it would be against his questions. The fourth
and worst kind of objection is that which is directed to the time
allowed for discussion: for some people bring objections of a kind
which would take longer to answer than the length of the discussion
in hand. 

There are then, as we said, four ways of making objections: but of
them the first alone is a solution: the others are just hindrances
and stumbling-blocks to prevent the conclusions. 


Part 11

Adverse criticism of an argument on its own merits, and of it when
presented in the form of questions, are two different things. For
often the failure to carry through the argument correctly in discussion
is due to the person questioned, because he will not grant the steps
of which a correct argument might have been made against his position:
for it is not in the power of the one side only to effect properly
a result that depends on both alike. Accordingly it sometimes becomes
necessary to attack the speaker and not his position, when the answerer
lies in wait for the points that are contrary to the questioner and
becomes abusive as well: when people lose their tempers in this way,
their argument becomes a contest, not a discussion. Moreover, since
arguments of this kind are held not for the sake of instruction but
for purposes of practice and examination, clearly one has to reason
not only to true conclusions, but also to false ones, and not always
through true premisses, but sometimes through false as well. For often,
when a true proposition is put forward, the dialectician is compelled
to demolish it: and then false propositions have to be formulated.
Sometimes also when a false proposition is put forward, it has to
be demolished by means of false propositions: for it is possible for
a given man to believe what is not the fact more firmly than the truth.
Accordingly, if the argument be made to depend on something that he
holds, it will be easier to persuade or help him. He, however, who
would rightly convert any one to a different opinion should do so
in a dialectical and not in a contentious manner, just as a geometrician
should reason geometrically, whether his conclusion be false or true:
what kind of syllogisms are dialectical has already been said. The
principle that a man who hinders the common business is a bad partner,
clearly applies to an argument as well; for in arguments as well there
is a common aim in view, except with mere contestants, for these cannot
both reach the same goal; for more than one cannot possibly win. It
makes no difference whether he effects this as answerer or as questioner:
for both he who asks contentious questions is a bad dialectician,
and also he who in answering fails to grant the obvious answer or
to understand the point of the questioner's inquiry. What has been
said, then, makes it clear that adverse criticism is not to be passed
in a like strain upon the argument on its own merits, and upon the
questioner: for it may very well be that the argument is bad, but
that the questioner has argued with the answerer in the best possible
way: for when men lose their tempers, it may perhaps be impossible
to make one's inferences straight-forwardly as one would wish: we
have to do as we can. 

Inasmuch as it is indeterminate when people are claiming the admission
of contrary things, and when they are claiming what originally they
set out to prove-for often when they are talking by themselves they
say contrary things, and admit afterwards what they have previously
denied; for which reason they often assent, when questioned, to contrary
things and to what originally had to be proved-the argument is sure
to become vitiated. The responsibility, however, for this rests with
the answerer, because while refusing to grant other points, he does
grant points of that kind. It is, then, clear that adverse criticism
is not to be passed in a like manner upon questioners and upon their
arguments. 

In itself an argument is liable to five kinds of adverse criticism:

(1) The first is when neither the proposed conclusion nor indeed any
conclusion at all is drawn from the questions asked, and when most,
if not all, of the premisses on which the conclusion rests are false
or generally rejected, when, moreover, neither any withdrawals nor
additions nor both together can bring the conclusions about.

(2) The second is, supposing the reasoning, though constructed from
the premisses, and in the manner, described above, were to be irrelevant
to the original position. 

(3) The third is, supposing certain additions would bring an inference
about but yet these additions were to be weaker than those that were
put as questions and less generally held than the conclusion.

(4) Again, supposing certain withdrawals could effect the same: for
sometimes people secure more premisses than are necessary, so that
it is not through them that the inference comes about. 

(5) Moreover, suppose the premisses be less generally held and less
credible than the conclusion, or if, though true, they require more
trouble to prove than the proposed view. 

One must not claim that the reasoning to a proposed view shall in
every case equally be a view generally accepted and convincing: for
it is a direct result of the nature of things that some subjects of
inquiry shall be easier and some harder, so that if a man brings people
to accept his point from opinions that are as generally received as
the case admits, he has argued his case correctly. Clearly, then,
not even the argument itself is open to the same adverse criticism
when taken in relation to the proposed conclusion and when taken by
itself. For there is nothing to prevent the argument being open to
reproach in itself, and yet commendable in relation to the proposed
conclusion, or again, vice versa, being commendable in itself, and
yet open to reproach in relation to the proposed conclusion, whenever
there are many propositions both generally held and also true whereby
it could easily be proved. It is possible also that an argument, even
though brought to a conclusion, may sometimes be worse than one which
is not so concluded, whenever the premisses of the former are silly,
while its conclusion is not so; whereas the latter, though requiring
certain additions, requires only such as are generally held and true,
and moreover does not rest as an argument on these additions. With
those which bring about a true conclusion by means of false premisses,
it is not fair to find fault: for a false conclusion must of necessity
always be reached from a false premiss, but a true conclusion may
sometimes be drawn even from false premisses; as is clear from the
Analytics. 

Whenever by the argument stated something is demonstrated, but that
something is other than what is wanted and has no bearing whatever
on the conclusion, then no inference as to the latter can be drawn
from it: and if there appears to be, it will be a sophism, not a proof.
A philosopheme is a demonstrative inference: an epichireme is a dialectical
inference: a sophism is a contentious inference: an aporeme is an
inference that reasons dialectically to a contradiction.

If something were to be shown from premisses, both of which are views
generally accepted, but not accepted with like conviction, it may
very well be that the conclusion shown is something held more strongly
than either. If, on the other hand, general opinion be for the one
and neither for nor against the other, or if it be for the one and
against the other, then, if the pro and con be alike in the case of
the premisses, they will be alike for the conclusion also: if, on
the other hand, the one preponderates, the conclusion too will follow
suit. 

It is also a fault in reasoning when a man shows something through
a long chain of steps, when he might employ fewer steps and those
already included in his argument: suppose him to be showing (e.g.)
that one opinion is more properly so called than another, and suppose
him to make his postulates as follows: 'x-in-itself is more fully
x than anything else': 'there genuinely exists an object of opinion
in itself': therefore 'the object-of-opinion-in-itself is more fully
an object of opinion than the particular objects of opinion'. Now
'a relative term is more fully itself when its correlate is more fully
itself': and 'there exists a genuine opinion-in-itself, which will
be "opinion" in a more accurate sense than the particular opinions':
and it has been postulated both that 'a genuine opinion-in-itself
exists', and that 'x-in-itself is more fully x than anything else':
therefore 'this will be opinion in a more accurate sense'. Wherein
lies the viciousness of the reasoning? Simply in that it conceals
the ground on which the argument depends. 


Part 12

An argument is clear in one, and that the most ordinary, sense, if
it be so brought to a conclusion as to make no further questions necessary:
in another sense, and this is the type most usually advanced, when
the propositions secured are such as compel the conclusion, and the
argument is concluded through premisses that are themselves conclusions:
moreover, it is so also if some step is omitted that generally is
firmly accepted. 

An argument is called fallacious in four senses: (1) when it appears
to be brought to a conclusion, and is not really so-what is called
'contentious' reasoning: (2) when it comes to a conclusion but not
to the conclusion proposed-which happens principally in the case of
reductiones ad impossibile: (3) when it comes to the proposed conclusion
but not according to the mode of inquiry appropriate to the case,
as happens when a non-medical argument is taken to be a medical one,
or one which is not geometrical for a geometrical argument, or one
which is not dialectical for dialectical, whether the result reached
be true or false: (4) if the conclusion be reached through false premisses:
of this type the conclusion is sometimes false, sometimes true: for
while a false conclusion is always the result of false premisses,
a true conclusion may be drawn even from premisses that are not true,
as was said above as well. 

Fallacy in argument is due to a mistake of the arguer rather than
of the argument: yet it is not always the fault of the arguer either,
but only when he is not aware of it: for we often accept on its merits
in preference to many true ones an argument which demolishes some
true proposition if it does so from premisses as far as possible generally
accepted. For an argument of that kind does demonstrate other things
that are true: for one of the premisses laid down ought never to be
there at all, and this will then be demonstrated. If, however, a true
conclusion were to be reached through premisses that are false and
utterly childish, the argument is worse than many arguments that lead
to a false conclusion, though an argument which leads to a false conclusion
may also be of this type. Clearly then the first thing to ask in regard
to the argument in itself is, 'Has it a conclusion?'; the second,
'Is the conclusion true or false?'; the third, 'Of what kind of premisses
does it consist?': for if the latter, though false, be generally accepted,
the argument is dialectical, whereas if, though true, they be generally
rejected, it is bad: if they be both false and also entirely contrary
to general opinion, clearly it is bad, either altogether or else in
relation to the particular matter in hand. 


Part 13

Of the ways in which a questioner may beg the original question and
also beg contraries the true account has been given in the Analytics:'
but an account on the level of general opinion must be given now.

People appear to beg their original question in five ways: the first
and most obvious being if any one begs the actual point requiring
to be shown: this is easily detected when put in so many words; but
it is more apt to escape detection in the case of different terms,
or a term and an expression, that mean the same thing. A second way
occurs whenever any one begs universally something which he has to
demonstrate in a particular case: suppose (e.g.) he were trying to
prove that the knowledge of contraries is one and were to claim that
the knowledge of opposites in general is one: for then he is generally
thought to be begging, along with a number of other things, that which
he ought to have shown by itself. A third way is if any one were to
beg in particular cases what he undertakes to show universally: e.g.
if he undertook to show that the knowledge of contraries is always
one, and begged it of certain pairs of contraries: for he also is
generally considered to be begging independently and by itself what,
together with a number of other things, he ought to have shown. Again,
a man begs the question if he begs his conclusion piecemeal: supposing
e.g. that he had to show that medicine is a science of what leads
to health and to disease, and were to claim first the one, then the
other; or, fifthly, if he were to beg the one or the other of a pair
of statements that necessarily involve one other; e.g. if he had to
show that the diagonal is incommensurable with the side, and were
to beg that the side is incommensurable with the diagonal.

The ways in which people assume contraries are equal in number to
those in which they beg their original question. For it would happen,
firstly, if any one were to beg an opposite affirmation and negation;
secondly, if he were to beg the contrary terms of an antithesis, e.g.
that the same thing is good and evil; thirdly, suppose any one were
to claim something universally and then proceed to beg its contradictory
in some particular case, e.g. if having secured that the knowledge
of contraries is one, he were to claim that the knowledge of what
makes for health or for disease is different; or, fourthly, suppose
him, after postulating the latter view, to try to secure universally
the contradictory statement. Again, fifthly, suppose a man begs the
contrary of the conclusion which necessarily comes about through the
premisses laid down; and this would happen suppose, even without begging
the opposites in so many words, he were to beg two premisses such
that this contradictory statement that is opposite to the first conclusion
will follow from them. The securing of contraries differs from begging
the original question in this way: in the latter case the mistake
lies in regard to the conclusion; for it is by a glance at the conclusion
that we tell that the original question has been begged: whereas contrary
views lie in the premisses, viz. in a certain relation which they
bear to one another. 


Part 14

The best way to secure training and practice in arguments of this
kind is in the first place to get into the habit of converting the
arguments. For in this way we shall be better equipped for dealing
with the proposition stated, and after a few attempts we shall know
several arguments by heart. For by 'conversion' of an argument is
meant the taking the reverse of the conclusion together with the remaining
propositions asked and so demolishing one of those that were conceded:
for it follows necessarily that if the conclusion be untrue, some
one of the premisses is demolished, seeing that, given all the premisses,
the conclusion was bound to follow. Always, in dealing with any proposition,
be on the look-out for a line of argument both pro and con: and on
discovering it at once set about looking for the solution of it: for
in this way you will soon find that you have trained yourself at the
same time in both asking questions and answering them. If we cannot
find any one else to argue with, we should argue with ourselves. Select,
moreover, arguments relating to the same thesis and range them side
by side: for this produces a plentiful supply of arguments for carrying
a point by sheer force, and in refutation also it is of great service,
whenever one is well stocked with arguments pro and con: for then
you find yourself on your guard against contrary statements to the
one you wish to secure. Moreover, as contributing to knowledge and
to philosophic wisdom the power of discerning and holding in one view
the results of either of two hypotheses is no mean instrument; for
it then only remains to make a right choice of one of them. For a
task of this kind a certain natural ability is required: in fact real
natural ability just is the power right to choose the true and shun
the false. Men of natural ability can do this; for by a right liking
or disliking for whatever is proposed to them they rightly select
what is best. 

It is best to know by heart arguments upon those questions which are
of most frequent occurrence, and particularly in regard to those propositions
which are ultimate: for in discussing these answerers frequently give
up in despair. Moreover, get a good stock of definitions: and have
those of familiar and primary ideas at your fingers' ends: for it
is through these that reasonings are effected. You should try, moreover,
to master the heads under which other arguments mostly tend to fall.
For just as in geometry it is useful to be practised in the elements,
and in arithmetic to have the multiplication table up to ten at one's
fingers' ends-and indeed it makes a great difference in one's knowledge
of the multiples of other numbers too-likewise also in arguments it
is a great advantage to be well up in regard to first principles,
and to have a thorough knowledge of premisses at the tip of one's
tongue. For just as in a person with a trained memory, a memory of
things themselves is immediately caused by the mere mention of their
loci, so these habits too will make a man readier in reasoning, because
he has his premisses classified before his mind's eye, each under
its number. It is better to commit to memory a premiss of general
application than an argument: for it is difficult to be even moderately
ready with a first principle, or hypothesis. 

Moreover, you should get into the habit of turning one argument into
several, and conceal your procedure as darkly as you can: this kind
of effect is best produced by keeping as far as possible away from
topics akin to the subject of the argument. This can be done with
arguments that are entirely universal, e.g. the statement that 'there
cannot be one knowledge of more than one thing': for that is the case
with both relative terms and contraries and co-ordinates.

Records of discussions should be made in a universal form, even though
one has argued only some particular case: for this will enable one
to turn a single rule into several. A like rule applies in Rhetoric
as well to enthymemes. For yourself, however, you should as far as
possible avoid universalizing your reasonings. You should, moreover,
always examine arguments to see whether they rest on principles of
general application: for all particular arguments really reason universally,
as well, i.e. a particular demonstration always contains a universal
demonstration, because it is impossible to reason at all without using
universals. 

You should display your training in inductive reasoning against a
young man, in deductive against an expert. You should try, moreover,
to secure from those skilled in deduction their premisses, from inductive
reasoners their parallel cases; for this is the thing in which they
are respectively trained. In general, too, from your exercises in
argumentation you should try to carry away either a syllogism on some
subject or a refutation or a proposition or an objection, or whether
some one put his question properly or improperly (whether it was yourself
or some one else) and the point which made it the one or the other.
For this is what gives one ability, and the whole object of training
is to acquire ability, especially in regard to propositions and objections.
For it is the skilled propounder and objector who is, speaking generally,
a dialectician. To formulate a proposition is to form a number of
things into one-for the conclusion to which the argument leads must
be taken generally, as a single thing-whereas to formulate an objection
is to make one thing into many; for the objector either distinguishes
or demolishes, partly granting, partly denying the statements proposed.

Do not argue with every one, nor practise upon the man in the street:
for there are some people with whom any argument is bound to degenerate.
For against any one who is ready to try all means in order to seem
not to be beaten, it is indeed fair to try all means of bringing about
one's conclusion: but it is not good form. Wherefore the best rule
is, not lightly to engage with casual acquaintances, or bad argument
is sure to result. For you see how in practising together people cannot
refrain from contentious argument. 

It is best also to have ready-made arguments relating to those questions
in which a very small stock will furnish us with arguments serviceable
on a very large number of occasions. These are those that are universal,
and those in regard to which it is rather difficult to produce points
for ourselves from matters of everyday experience. 

END


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