Things are said to be named 'equivocally' when, though they have a common name, the definition corresponding

with the name differs for each. Thus, a real man and a figure in a picture can both

lay claim to the name 'animal'; yet these are equivocally so named, for, though they have

a common name, the definition corresponding with the name differs for each. For should any

one define in what sense each is an animal, his definition in the one case will

be appropriate to that case only. On the other hand, things are said to be

named 'univocally' which have both the name and the definition answering to the name in common.

A man and an ox are both 'animal', and these are univocally so named,

inasmuch as not only the name, but also the definition, is the

same in both cases: for if a man should state in what sense each

is an animal, the statement in the one case would be identical with that

in the other. Things are said to be named 'derivatively', which derive their

name from some other name, but differ from it in termination. Thus the

grammarian derives his name from the word 'grammar', and the courageous man

from the word 'courage'.

Forms of speech are either simple or

composite. Examples of the latter are such expressions as

'the man runs', 'the man wins'; of the former 'man',

'ox', 'runs', 'wins'.

Of things themselves some are predicable of a subject, and

are never present in a subject. Thus 'man' is predicable of

the individual man, and is never present in a subject.

By being 'present in a subject' I do not mean present as parts are

present in a whole, but being incapable of existence apart from the said subject.

Some things, again, are present in a subject, but are never predicable of

a subject. For instance, a certain point of grammatical knowledge is present in

the mind, but is not predicable of any subject; or again, a certain whiteness

may be present in the body (for colour requires a material basis), yet

it is never predicable of anything. Other things, again, are both

predicable of a subject and present in a subject. Thus while

knowledge is present in the human mind, it is predicable

of grammar. There is, lastly, a class of things

which are neither present in a subject nor predicable

of a subject, such as the individual man or

the individual horse. But, to speak more generally, that which is individual and

has the character of a unit is never predicable of a subject. Yet in some cases there is nothing to

prevent such being present in a subject. Thus a certain point of grammatical knowledge is present

in a subject.

When one thing is predicated of another, all that

which is predicable of the predicate will be predicable

also of the subject. Thus, 'man' is predicated of

the individual man; but 'animal' is predicated of 'man';

it will, therefore, be predicable of the individual man also:

for the individual man is both 'man' and 'animal'.

If genera are different and co-ordinate, their differentiae are themselves different in kind.

Take as an instance the genus 'animal' and the genus 'knowledge'.

'With feet', 'two-footed', 'winged', 'aquatic', are differentiae of 'animal'; the species

of knowledge are not distinguished by the same differentiae. One species

of knowledge does not differ from another in being 'two-footed'. But where one

genus is subordinate to another, there is nothing to prevent their having the same differentiae:

for the greater class is predicated of the lesser, so that

all the differentiae of the predicate will be differentiae also

of the subject.

Expressions which are in no way composite signify

substance, quantity, quality, relation, place, time, position,

state, action, or affection. To sketch my meaning roughly, examples

of substance are 'man' or 'the horse', of quantity, such terms as 'two cubits long' or 'three

cubits long', of quality, such attributes as 'white', 'grammatical'. 'Double', 'half', 'greater',

fall under the category of relation; 'in a the market place', 'in the Lyceum', under that of

place; 'yesterday', 'last year', under that of time. 'Lying', 'sitting', are terms indicating position,

'shod', 'armed', state; 'to lance', 'to

cauterize', action; 'to be lanced', 'to be cauterized', affection. No

one of these terms, in and by itself, involves an affirmation; it

is by the combination of such terms that positive or

negative statements arise. For every assertion must, as is admitted,

be either true or false, whereas expressions which are

not in any way composite such as 'man', 'white', 'runs', 'wins',

cannot be either true or false.

Substance, in the truest and primary and most definite sense of

the word, is that which is neither predicable of a subject

nor present in a subject; for instance, the individual man or horse.

But in a secondary sense those things are called substances within which,

as species, the primary substances are included; also those which, as genera,

include the species. For instance, the individual man is included in the species

'man', and the genus to which the species belongs is 'animal'; these,

therefore-that is to say, the species 'man' and the genus 'animal,-are termed secondary

substances. It is plain from what has been said that

both the name and the definition of the predicate must be

predicable of the subject. For instance, 'man' is predicted of

the individual man. Now in this case the name of the species man' is

applied to the individual, for we use the term 'man' in describing the individual;

and the definition of 'man' will also be predicated of

the individual man, for the individual man is both man and

animal. Thus, both the name and the definition of the species

are predicable of the individual. With regard, on the other hand, to those things which

are present in a subject, it is generally the case that neither their name nor their definition is predicable

of that in which they are present. Though, however, the definition is never predicable, there

is nothing in certain cases to prevent the name being used.

For instance, 'white' being present in a body is predicated of

that in which it is present, for a body is called white:

the definition, however, of the colour white' is never predicable of the

body. Everything except primary substances is either predicable of a

primary substance or present in a primary substance. This becomes

evident by reference to particular instances which occur. 'Animal' is predicated

of the species 'man', therefore of the individual man, for if there were

no individual man of whom it could be predicated, it could not be

predicated of the species 'man' at all. Again, colour is present

in body, therefore in individual bodies, for if there were no individual

body in which it was present, it could not be present in body at all. Thus everything

except primary substances is either predicated of primary substances,

or is present in them, and if these last

did not exist, it would be impossible for anything else to exist.

Of secondary substances, the species is more truly substance than the genus,

being more nearly related to primary substance. For if any one

should render an account of what a primary substance is, he would render a more instructive account, and

one more proper to the subject, by stating the species than by stating the genus. Thus,

he would give a more instructive account of an individual man by stating that he was man than

by stating that he was animal, for the former description is peculiar to the individual in a greater

degree, while the latter is too general. Again, the man who gives an account of the nature of an individual

tree will give a more instructive account by mentioning the species 'tree' than by mentioning the genus 'plant'.

Moreover, primary substances are most properly called substances in virtue of the fact

that they are the entities which underlie everything else, and that everything

else is either predicated of them or present in them. Now the

same relation which subsists between primary substance and everything else subsists also

between the species and the genus: for the species is to the genus as subject is

to predicate, since the genus is predicated of the species, whereas the

species cannot be predicated of the genus. Thus we have a second

ground for asserting that the species is more truly substance than the genus. Of species themselves, except in

the case of such as are genera, no one is more truly substance than another.

We should not give a more appropriate account of the individual man by stating the

species to which he belonged, than we should of an individual horse by adopting the same method

of definition. In the same way, of primary substances, no one is more

truly substance than another; an individual man is not more truly substance

than an individual ox.

It is, then, with good reason that of all that remains, when we exclude primary

substances, we concede to species and genera alone the name 'secondary substance', for these alone

of all the predicates convey a knowledge of primary substance. For it

is by stating the species or the genus that we appropriately define any individual

man; and we shall make our definition more exact by stating the former than

by stating the latter. All other things that we

state, such as that he is white, that he runs, and

so on, are irrelevant to the definition. Thus it is just that these

alone, apart from primary substances, should be called substances. Further, primary substances are most

properly so called, because they underlie and are the subjects of everything

else. Now the same relation that subsists between primary substance and everything else subsists also between the

species and the genus to which the primary substance belongs, on the one hand, and every attribute which is not

included within these, on the other. For these are the subjects of all

such. If we call an individual man 'skilled in grammar', the predicate is

applicable also to the species and to the genus to which he belongs. This law

holds good in all cases.

It is a common characteristic of all substance that it is never present in a

subject. For primary substance is neither present in a subject nor

predicated of a subject; while, with regard to secondary substances, it is

clear from the following arguments (apart from others) that they are not present in a subject. For 'man'

is predicated of the individual man, but is not present

in any subject: for manhood is not present in the individual

man. In the same way, 'animal' is also

predicated of the individual man, but is not present in

him. Again, when a thing is present in a subject, though

the name may quite well be applied to that in which it is present, the

definition cannot be applied. Yet of secondary substances, not only the name,

but also the definition, applies to the subject: we should use both

the definition of the species and that of the genus with reference

to the individual man. Thus substance cannot be present in

a subject. Yet this is not peculiar to substance, for it is

also the case that differentiae cannot be present in subjects. The characteristics

'terrestrial' and 'two-footed' are predicated of the species

'man', but not present in it. For they are

not in man. Moreover, the definition of the differentia may be predicated

of that of which the differentia itself is predicated. For instance, if the

characteristic 'terrestrial' is predicated of the species 'man', the definition also of that characteristic

may be used to form the predicate of the species 'man': for 'man' is terrestrial.

The fact that the parts of substances appear to be present in the whole,

as in a subject, should not make us apprehensive lest we should have to admit that

such parts are not substances: for in explaining the phrase 'being present in a subject',

we stated' that we meant 'otherwise than as parts in a whole'.

It is the mark of substances and of differentiae that, in all propositions of which they

form the predicate, they are predicated univocally. For all such propositions have

for their subject either the individual or the species.

It is true that, inasmuch as primary substance is not predicable

of anything, it can never form the predicate of any proposition. But of

secondary substances, the species is predicated of the individual,

the genus both of the species and of the individual.

Similarly the differentiae are predicated of the species and

of the individuals. Moreover, the definition of the species and

that of the genus are applicable to the primary substance, and that of the

genus to the species. For all that is predicated of the

predicate will be predicated also of the subject. Similarly, the definition

of the differentiae will be applicable to the species and to

the individuals. But it was stated above that the word 'univocal' was applied to those things which had

both name and definition in common. It is, therefore, established that in every proposition, of which either substance

or a differentia forms the predicate, these are predicated univocally.

All substance appears to signify that which is individual. In the

case of primary substance this is indisputably

true, for the thing is a unit.

In the case of secondary substances, when we speak, for instance, of 'man'

or 'animal', our form of speech gives the impression that we are here also indicating that

which is individual, but the impression is not strictly true; for a secondary substance is

not an individual, but a class with a certain qualification; for it is not one and single as

a primary substance is; the words 'man', 'animal', are predicable of more than one subject.

Yet species and genus do not merely indicate quality, like the term 'white';

'white' indicates quality and nothing further, but species and genus

determine the quality with reference to a substance: they signify

substance qualitatively differentiated. The determinate qualification covers a larger field in the case of

the genus that in that of the species: he who uses the word 'animal' is herein using a word of

wider extension than he who uses the word 'man'.

Another mark of substance is that it has no contrary.

What could be the contrary of any primary substance, such as the individual man or animal? It has

none. Nor can the species or the genus have

a contrary. Yet this characteristic is not peculiar to substance, but is

true of many other things, such as quantity. There is nothing that forms the contrary of

'two cubits long' or of 'three cubits long', or of 'ten', or of any such term. A

man may contend that 'much' is the contrary of 'little', or 'great' of 'small', but

of definite quantitative terms no contrary exists.

Substance, again, does not appear to admit of variation of degree.

I do not mean by this that one substance cannot be more or less

truly substance than another, for it has already been stated' that this is the

case; but that no single substance admits of varying degrees within itself.

For instance, one particular substance, 'man', cannot be more or less man either

than himself at some other time or than some other man.

One man cannot be more man than another, as that which is white may be more or

less white than some other white object, or as that which is beautiful may be more or

less beautiful than some other beautiful object. The same quality, moreover, is said to subsist in

a thing in varying degrees at different times. A body, being white, is said to be

whiter at one time than it was before, or, being warm, is said to be warmer

or less warm than at some other time. But substance is not said to be

more or less that which it is: a man is not more truly a man at one

time than he was before, nor is anything, if it is substance, more or less what it

is. Substance, then, does not admit of variation of degree.

The most distinctive mark of substance appears to be that, while remaining numerically one and

the same, it is capable of admitting contrary qualities. From among things

other than substance, we should find ourselves unable to

bring forward any which possessed this mark.

Thus, one and the same colour cannot be white and

black. Nor can the same one action be good

and bad: this law holds good with everything that

is not substance. But one and the selfsame substance,

while retaining its identity, is yet capable of admitting contrary qualities. The same individual

person is at one time white, at another black, at one

time warm, at another cold, at one time good, at another

bad. This capacity is found nowhere else, though it might

be maintained that a statement or opinion was an exception

to the rule. The same statement, it is agreed, can be

both true and false. For if the statement 'he is sitting' is true, yet,

when the person in question has risen, the same statement will be

false. The same applies to opinions. For if any one thinks

truly that a person is sitting, yet, when that person has risen, this same

opinion, if still held, will be false. Yet although this exception may be allowed, there is,

nevertheless, a difference in the manner in which the thing takes place. It is by themselves

changing that substances admit contrary qualities. It is thus that that which was hot becomes

cold, for it has entered into a different state. Similarly that which was white

becomes black, and that which was bad good, by a process of change;

and in the same way in all other cases it is by changing

that substances are capable of admitting contrary qualities. But statements and opinions themselves

remain unaltered in all respects: it is by the alteration in the facts

of the case that the contrary quality comes to be theirs. The statement

'he is sitting' remains unaltered, but it is at

one time true, at another false, according to circumstances.

What has been said of statements applies also to opinions. Thus, in respect of the manner in which

the thing takes place, it is the peculiar mark of substance that it should be capable of admitting

contrary qualities; for it is by itself changing that it does so. If, then, a man should make

this exception and contend that statements and opinions are capable of admitting contrary qualities, his contention

is unsound. For statements and opinions are said to have this

capacity, not because they themselves undergo modification, but because this modification occurs in

the case of something else. The truth or falsity of a

statement depends on facts, and not on any power on the

part of the statement itself of admitting contrary qualities. In short, there

is nothing which can alter the nature of statements and opinions. As, then, no change

takes place in themselves, these cannot be said to be capable of admitting contrary qualities.

But it is by reason of the modification which takes place within the substance itself that a substance

is said to be capable of admitting contrary qualities; for a substance admits within

itself either disease or health, whiteness or blackness. It is in this

sense that it is said to be capable of admitting contrary qualities.

To sum up, it is a distinctive mark of substance, that, while remaining numerically one and the same, it is capable of admitting contrary qualities, the modification

taking place through a change in the substance itself. Let these remarks suffice on the subject of

substance.

Quantity is either discrete or continuous.

Moreover, some quantities are such that each part of the whole has a relative position to the

other parts: others have within them no such relation of part to part. Instances of

discrete quantities are number and speech; of continuous, lines, surfaces,

solids, and, besides these, time and place.

In the case of the parts of a number, there is

no common boundary at which they join. For example: two

fives make ten, but the two fives have no common

boundary, but are separate; the parts three and seven

also do not join at any boundary. Nor, to generalize, would it

ever be possible in the case of number that there should be a common boundary among the parts;

they are always separate. Number, therefore, is a discrete quantity.

The same is true of speech. That speech

is a quantity is evident: for it is measured in long

and short syllables. I mean here that speech which

is vocal. Moreover, it is a discrete quantity for its parts have

no common boundary. There is no common boundary at which the syllables join,

but each is separate and distinct from the rest.

A line, on the other hand, is a continuous quantity, for it is possible to find

a common boundary at which its parts join. In the case of the

line, this common boundary is the point; in the case of the plane, it is the line: for the parts of

the plane have also a common boundary. Similarly you can find a common boundary

in the case of the parts of a solid, namely either

a line or a plane. Space and time also belong

to this class of quantities. Time, past, present, and future,

forms a continuous whole. Space, likewise, is a

continuous quantity; for the parts of a solid occupy a certain

space, and these have a common boundary; it follows that the

parts of space also, which are occupied by the parts of the

solid, have the same common boundary as the parts of the

solid. Thus, not only time, but space also, is a continuous quantity, for its

parts have a common boundary.

Quantities consist either of parts which bear a relative position

each to each, or of parts which do not.

The parts of a line bear a relative position to each other, for each

lies somewhere, and it would be possible to distinguish each, and to state the position

of each on the plane and to explain to what sort of

part among the rest each was contiguous. Similarly the parts of a

plane have position, for it could similarly be stated what was

the position of each and what sort of parts were contiguous. The

same is true with regard to the solid and to space. But it

would be impossible to show that the parts of a number had

a relative position each to each, or a particular position, or

to state what parts were contiguous. Nor could this be done in the case of time,

for none of the parts of time has an abiding existence, and that

which does not abide can hardly have position. It would be

better to say that such parts had a relative order, in virtue of one

being prior to another. Similarly with number: in counting, 'one'

is prior to 'two', and 'two' to 'three',

and thus the parts of number may be said to possess a relative order, though it would be impossible to discover any distinct position for each.

This holds good also in the case of speech. None of its parts has an

abiding existence: when once a syllable is pronounced, it is not possible to

retain it, so that, naturally, as the parts do not abide, they cannot have

position. Thus, some quantities consist of parts which have position, and

some of those which have not.

Strictly speaking, only the things which I have mentioned belong to the category of quantity: everything else

that is called quantitative is a quantity in a secondary sense. It is because we have

in mind some one of these quantities, properly so called, that we apply quantitative terms to other things.

We speak of what is white as large, because the surface over which the white extends is large; we

speak of an action or a process as lengthy, because the time covered is long; these things

cannot in their own right claim the quantitative epithet. For instance, should any one explain

how long an action was, his statement would be made in terms of the time taken,

to the effect that it lasted a year, or something of that sort. In the same way,

he would explain the size of a white object in terms of surface, for he would state

the area which it covered. Thus the things already mentioned, and these alone, are in

their intrinsic nature quantities; nothing else can claim the name in its own right, but, if

at all, only in a secondary sense.

Quantities have no contraries. In the case of definite quantities this is

obvious; thus, there is nothing that is the contrary of 'two cubits

long' or of 'three cubits long', or of a surface, or of

any such quantities. A man might, indeed, argue that 'much' was

the contrary of 'little', and 'great' of 'small'. But these

are not quantitative, but relative; things are not great or small

absolutely, they are so called rather as the result of an act

of comparison. For instance, a mountain is called small, a grain large, in

virtue of the fact that the latter is greater than others of its kind,

the former less. Thus there is a reference here to an external standard,

for if the terms 'great' and 'small' were used absolutely, a mountain

would never be called small or a grain large. Again, we say that there

are many people in a village, and few in Athens, although those in the city are many

times as numerous as those in the village: or we say that a house has many in

it, and a theatre few, though those in the theatre far outnumber those in the house. The

terms 'two cubits long, "three cubits long,' and so

on indicate quantity, the terms 'great' and 'small'

indicate relation, for they have reference to an external

standard. It is, therefore, plain that these are to be classed as relative. Again,

whether we define them as quantitative or not, they

have no contraries: for how can there be a contrary of an

attribute which is not to be apprehended in or by itself, but only by reference

to something external? Again, if 'great' and 'small' are contraries, it will come about

that the same subject can admit contrary qualities at one and the same time, and that

things will themselves be contrary to themselves. For it happens at times that

the same thing is both small and great. For the same thing may be small in

comparison with one thing, and great in comparison with another, so that the

same thing comes to be both small and great at

one and the same time, and is of such a nature as

to admit contrary qualities at one and the same moment. Yet it was agreed, when substance was being discussed, that

nothing admits contrary qualities at one and the same moment. For though substance is capable of admitting contrary qualities, yet no one

is at the same time both sick and healthy, nothing is at the same time both white and black. Nor

is there anything which is qualified in contrary ways at one and the same time. Moreover, if

these were contraries, they would themselves be contrary to themselves. For if 'great' is the

contrary of 'small', and the same thing is both great and small at the same time,

then 'small' or 'great' is the contrary of itself. But this

is impossible. The term 'great', therefore, is not

the contrary of the term 'small', nor 'much' of 'little'. And even though

a man should call these terms not relative but quantitative, they would not

have contraries. It is in the case of space that quantity most plausibly appears to

admit of a contrary. For men define the term 'above' as the contrary of 'below', when it

is the region at the centre they mean by 'below'; and this is so, because nothing is

farther from the extremities of the universe than the region at the centre. Indeed, it seems

that in defining contraries of every kind men have recourse to a spatial metaphor,

for they say that those things are contraries which, within the same class, are separated

by the greatest possible distance.

Quantity does not, it appears, admit of variation of degree. One

thing cannot be two cubits long in a greater degree than another.

Similarly with regard to number: what is 'three' is not more truly three than what is

'five' is five; nor is one set of three more truly three than another set. Again, one period

of time is not said to be more truly time than another. Nor is there any other

kind of quantity, of all that have been mentioned, with regard to which variation of degree can be predicated. The category

of quantity, therefore, does not admit of variation of degree.

The most distinctive mark of quantity is that equality and inequality are predicated of it.

Each of the aforesaid quantities is said to be equal

or unequal. For instance, one solid is said to be equal or

unequal to another; number, too, and time can have these

terms applied to them, indeed can all those kinds

of quantity that have been mentioned. That which

is not a quantity can by no means, it would seem, be

termed equal or unequal to anything else. One particular disposition or one particular quality,

such as whiteness, is by no means compared with another in terms of equality

and inequality but rather in terms of similarity. Thus it is the distinctive mark

of quantity that it can be called equal and unequal.

Those things are called relative, which, being either said to be of something else or

related to something else, are explained by reference to that other thing. For instance,

the word 'superior' is explained by reference to something else, for it is superiority over

something else that is meant. Similarly, the expression 'double' has this external reference, for it is

the double of something else that is meant. So it is with everything else of this

kind. There are, moreover, other relatives, e.g. habit, disposition,

perception, knowledge, and attitude. The significance of all these is

explained by a reference to something else and in no other way. Thus,

a habit is a habit of something, knowledge is knowledge of something, attitude is the attitude of

something. So it is with all other relatives that have been mentioned. Those terms, then,

are called relative, the nature of which is explained by reference to something else, the preposition 'of' or some other

preposition being used to indicate the relation. Thus, one mountain is called great in comparison with son with

another; for the mountain claims this attribute by comparison with something. Again, that which is called similar

must be similar to something else, and all other such attributes have this external reference.

It is to be noted that lying and standing and sitting are

particular attitudes, but attitude is itself a relative term. To lie, to stand,

to be seated, are not themselves attitudes, but take

their name from the aforesaid attitudes.

It is possible for relatives to have contraries. Thus virtue has

a contrary, vice, these both being relatives; knowledge, too, has a contrary,

ignorance. But this is not the mark of all relatives;

'double' and 'triple' have no contrary, nor indeed

has any such term. It also appears that

relatives can admit of variation of degree. For 'like' and

'unlike', 'equal' and 'unequal', have the modifications 'more' and 'less' applied to them, and

each of these is relative in character: for the terms 'like'

and 'unequal' bear a reference to something external. Yet, again, it is

not every relative term that admits of variation of degree. No term such

as 'double' admits of this

modification.

All relatives have correlatives: by the term 'slave' we mean the slave

of a master, by the term 'master', the master of a

slave; by 'double', the double of its hall; by 'half', the half

of its double; by 'greater', greater than that which is less; by 'less,'

less than that which is greater. So it is with every other relative

term; but the case we use to express the correlation differs in some instances.

Thus, by knowledge we mean knowledge the knowable; by the knowable, that which is

to be apprehended by knowledge; by perception, perception of the perceptible; by the perceptible,

that which is apprehended by perception. Sometimes, however, reciprocity of correlation does not appear to

exist. This comes about when a blunder is made, and that to which the relative

is related is not accurately stated. If a man states that a wing is necessarily relative

to a bird, the connexion between these two will not be reciprocal, for it will not be possible to

say that a bird is a bird by reason of its wings. The reason is that the original statement was

inaccurate, for the wing is not said to be relative to the bird qua bird,

since many creatures besides birds have wings, but qua winged creature. If, then, the statement

is made accurate, the connexion will be reciprocal, for we can speak of a wing, having reference necessarily to a winged

creature, and of a winged creature as being such because of its wings. Occasionally, perhaps, it is

necessary to coin words, if no word exists by which a correlation can

adequately be explained. If we define a rudder as necessarily having reference

to a boat, our definition will not be appropriate, for the rudder does not

have this reference to a boat qua boat, as there are boats which have

no rudders. Thus we cannot use the terms reciprocally, for the word 'boat' cannot be said to

find its explanation in the word 'rudder'. As there is no existing word, our

definition would perhaps be more accurate if we coined some word

like 'ruddered' as the correlative of 'rudder'. If we express

ourselves thus accurately, at any rate the terms are reciprocally connected, for the 'ruddered' thing is 'ruddered'

in virtue of its rudder. So it is in all other cases. A head

will be more accurately defined as the correlative of that which is 'headed', than as that

of an animal, for the animal does not have a head qua animal, since many

animals have no head. Thus we may perhaps most easily comprehend

that to which a thing is related, when a name does not exist, if, from that

which has a name, we derive a new name, and apply it to that with

which the first is reciprocally connected, as in the aforesaid instances, when we derived the

word 'winged' from 'wing' and from 'rudder'. All relatives, then, if

properly defined, have a correlative. I add

this condition because, if that to which they are related is stated as haphazard and not accurately,

the two are not found to be interdependent. Let me state what I mean more clearly.

Even in the case of acknowledged correlatives, and where names exist for each, there will

be no interdependence if one of the two is denoted, not by that name which expresses

the correlative notion, but by one of irrelevant significance. The term 'slave,' if

defined as related, not to a master, but to a man,

or a biped, or anything of that sort, is not reciprocally connected with that in relation to which

it is defined, for the statement is not exact. Further, if one thing is said to be correlative with another, and

the terminology used is correct, then, though all irrelevant attributes should be removed, and

only that one attribute left in virtue of which it was correctly stated to be

correlative with that other, the stated correlation will still exist. If the

correlative of 'the slave' is said to be 'the master', then, though

all irrelevant attributes of the said 'master', such as 'biped', 'receptive

of knowledge', 'human', should be removed, and the attribute 'master' alone

left, the stated correlation existing between him and the slave will

remain the same, for it is of a master that a slave is said to be

the slave. On the other hand, if, of two correlatives, one is not correctly termed, then,

when all other attributes are removed and that alone is left in virtue of which it

was stated to be correlative, the stated correlation will be found to have disappeared. For

suppose the correlative of 'the slave' should be said to be 'the man', or the correlative

of 'the wing' 'the bird'; if the attribute 'master' be withdrawn from' the man', the

correlation between 'the man' and 'the slave' will cease to exist, for if the man is not a

master, the slave is not a slave. Similarly, if the attribute 'winged' be

withdrawn from 'the bird', 'the wing' will no longer be

relative; for if the so-called correlative is not winged, it follows that 'the wing' has no correlative.

Thus it is essential that the correlated terms should be exactly designated; if

there is a name existing, the statement will be easy; if not, it

is doubtless our duty to construct names. When the terminology

is thus correct, it is evident that all correlatives are

interdependent.

Correlatives are thought to come into existence simultaneously. This is for the most part

true, as in the case of the double and the half. The existence of the half necessitates the existence of that

of which it is a half. Similarly the existence of a master necessitates the existence of a slave, and

that of a slave implies that of a master; these are merely instances of a general

rule. Moreover, they cancel one another; for if there

is no double it follows that there is no

half, and vice versa; this rule also applies to all such

correlatives. Yet it does not appear to be true in all cases that

correlatives come into existence simultaneously. The object of knowledge would appear to

exist before knowledge itself, for it is usually the case

that we acquire knowledge of objects already existing; it would

be difficult, if not impossible, to find a branch of knowledge the beginning of the existence of which was

contemporaneous with that of its object. Again, while the object of knowledge, if it ceases to

exist, cancels at the same time the knowledge which was its correlative, the converse of this is

not true. It is true that if the object of knowledge does not exist there can be no knowledge: for

there will no longer be anything to know. Yet it is equally true that, if knowledge of a certain object does not

exist, the object may nevertheless quite well exist. Thus, in the case of the squaring of the circle,

if indeed that process is an object of knowledge, though it itself exists as an object of knowledge,

yet the knowledge of it has not yet come into existence. Again, if all animals ceased to

exist, there would be no knowledge, but there might yet be many objects of

knowledge. This is likewise the case with regard to perception:

for the object of perception is, it appears, prior to the act of perception. If

the perceptible is annihilated, perception also will cease to exist; but the annihilation of perception

does not cancel the existence of the perceptible. For perception implies a body perceived and

a body in which perception takes place. Now if that which is perceptible is annihilated, it

follows that the body is annihilated, for the body is a perceptible thing; and

if the body does not exist, it follows that perception also ceases to exist. Thus

the annihilation of the perceptible involves that of perception. But the annihilation of perception does not involve

that of the perceptible. For if the animal is annihilated, it follows

that perception also is annihilated, but perceptibles such as body,

heat, sweetness, bitterness, and so on, will remain. Again, perception is

generated at the same time as the perceiving subject, for it

comes into existence at the same time as the animal. But the perceptible

surely exists before perception; for fire and water and such elements, out

of which the animal is itself composed, exist before the animal is an

animal at all, and before perception. Thus it would seem that the perceptible exists

before perception.

It may be questioned whether it is true that no substance is relative, as

seems to be the case, or whether exception is to be made in the

case of certain secondary substances. With regard to primary substances, it is quite true that there is

no such possibility, for neither wholes nor parts of primary substances are relative.

The individual man or ox is not defined with reference

to something external. Similarly with the parts:

a particular hand or head is not defined as a particular hand or head

of a particular person, but as the hand or head of a

particular person. It is true also, for the most part at least, in

the case of secondary substances; the species 'man' and the species 'ox' are not defined with reference

to anything outside themselves. Wood, again, is only relative in so far as it is some one's property, not

in so far as it is wood. It is plain, then, that in the

cases mentioned substance is not relative. But with regard to some secondary substances there

is a difference of opinion; thus, such terms as 'head' and 'hand' are

defined with reference to that of which the things indicated are a part, and

so it comes about that these appear to have a relative character. Indeed,

if our definition of that which is relative was complete, it

is very difficult, if not impossible, to prove that no

substance is relative. If, however, our definition was not complete, if those things only are properly called

relative in the case of which relation to an external object is a necessary condition of existence, perhaps some explanation

of the dilemma may be found. The former definition does indeed apply to

all relatives, but the fact that a thing is explained with reference

to something else does not make it essentially relative. From this

it is plain that, if a man definitely apprehends a relative thing, he will

also definitely apprehend that to which it is relative. Indeed

this is self-evident: for if a man knows that some particular thing

is relative, assuming that we call that a relative in the case of which relation to something

is a necessary condition of existence, he knows that also to which it is related.

For if he does not know at all that to which it is related, he will not

know whether or not it is relative. This is clear, moreover, in

particular instances. If a man knows definitely that such and such a thing is

'double', he will also forthwith know definitely that of which it is the double. For

if there is nothing definite of which he knows it to be the double,

he does not know at all that it is double. Again, if he knows

that a thing is more beautiful, it follows necessarily that he will forthwith definitely

know that also than which it is more beautiful. He will not merely know

indefinitely that it is more beautiful than something which is less beautiful, for this

would be supposition, not knowledge. For if he does not

know definitely that than which it is more beautiful, he can no longer claim to know definitely that it is more beautiful

than something else which is less beautiful: for it might be that nothing was less beautiful. It is, therefore, evident that if a man

apprehends some relative thing definitely, he necessarily knows that also definitely

to which it is related. Now the head, the hand, and such

things are substances, and it is possible to know their essential character definitely,

but it does not necessarily follow that we should know that to which they are

related. It is not possible to know forthwith whose head

or hand is meant. Thus these are not relatives,

and, this being the case, it would be true to say that

no substance is relative in character. It is perhaps a difficult

matter, in such cases, to make a positive statement without more

exhaustive examination, but to have raised questions with regard to details is not

without advantage.

By 'quality' I mean that in virtue of which people are said to be such and such. Quality is

a term that is used in many senses. One sort

of quality let us call 'habit' or 'disposition'. Habit differs from

disposition in being more lasting and more firmly established.

The various kinds of knowledge and of virtue are habits, for knowledge, even

when acquired only in a moderate degree, is, it is agreed, abiding

in its character and difficult to displace, unless some great mental

upheaval takes place, through disease or any such cause. The virtues,

also, such as justice, self-restraint, and so on, are

not easily dislodged or dismissed, so as to give place to

vice. By a disposition, on the other hand, we mean a condition that

is easily changed and quickly gives place to its opposite. Thus, heat, cold,

disease, health, and so on are dispositions. For a man is

disposed in one way or another with reference to these, but

quickly changes, becoming cold instead of warm, ill instead of well.

So it is with all other dispositions also, unless through lapse

of time a disposition has itself become inveterate and almost impossible to

dislodge: in which case we should perhaps go so far as to call

it a habit. It is evident that men incline to call those conditions habits

which are of a more or less permanent type and difficult to displace; for those

who are not retentive of knowledge, but volatile, are not said to have such

and such a 'habit' as regards knowledge, yet they are disposed, we may say,

either better or worse, towards knowledge. Thus habit differs from disposition in this,

that while the latter in ephemeral, the former is permanent and difficult

to alter. Habits are at the same time dispositions, but

dispositions are not necessarily habits. For those who have some specific habit may be said

also, in virtue of that habit, to be thus or thus disposed; but those who are disposed in some specific

way have not in all cases the corresponding habit.

Another sort of quality is that in virtue of which, for example, we call

men good boxers or runners, or healthy or sickly: in fact it includes

all those terms which refer to inborn capacity or incapacity. Such things are

not predicated of a person in virtue of his disposition, but in virtue of

his inborn capacity or incapacity to do something with ease or to avoid

defeat of any kind. Persons are called good boxers or good runners, not

in virtue of such and such a disposition, but in virtue of

an inborn capacity to accomplish something with ease. Men are called healthy in

virtue of the inborn capacity of easy resistance to those unhealthy influences that

may ordinarily arise; unhealthy, in virtue of the lack of this

capacity. Similarly with regard to softness and hardness.

Hardness is predicated of a thing because it has that capacity of resistance

which enables it to withstand disintegration; softness, again, is predicated of a thing by reason

of the lack of that capacity.

A third class within this category is that of affective qualities and affections.

Sweetness, bitterness, sourness, are examples of this sort of quality,

together with all that is akin to these; heat, moreover, and cold,

whiteness, and blackness are affective qualities. It is evident

that these are qualities, for those things that possess them are themselves said to

be such and such by reason of their presence. Honey is called sweet because it

contains sweetness; the body is called white because it contains whiteness;

and so in all other cases. The term 'affective

quality' is not used as indicating that those things which admit these qualities are

affected in any way. Honey is not called sweet because it is affected in

a specific way, nor is this what is meant in any other instance. Similarly

heat and cold are called affective qualities, not because

those things which admit them are affected. What

is meant is that these said qualities are

capable of producing an 'affection' in the way of

perception. For sweetness has the power of affecting the sense of taste;

heat, that of touch; and so it is with the rest of these

qualities. Whiteness and blackness, however, and the other colours, are

not said to be affective qualities in this sense, but -because

they themselves are the results of an affection. It is

plain that many changes of colour take place because of affections.

When a man is ashamed, he blushes; when he is afraid,

he becomes pale, and so on. So true is this, that when a man is

by nature liable to such affections, arising from some concomitance of elements in his constitution, it is a probable

inference that he has the corresponding complexion of skin. For the same disposition of bodily elements, which

in the former instance was momentarily present in the case of an access of

shame, might be a result of a man's natural temperament, so as to produce the

corresponding colouring also as a natural characteristic. All conditions, therefore, of

this kind, if caused by certain permanent and

lasting affections, are called affective qualities. For

pallor and duskiness of complexion are called qualities, inasmuch as we

are said to be such and such in virtue of them,

not only if they originate in natural constitution, but also if they

come about through long disease or sunburn, and are difficult to

remove, or indeed remain throughout life. For in the same way we

are said to be such and such because of these.

Those conditions, however, which arise from causes which may easily be rendered ineffective or speedily removed, are

called, not qualities, but affections: for we are not said to be such virtue

of them. The man who blushes through shame is not said to be a

constitutional blusher, nor is the man who becomes pale through fear said to be constitutionally

pale. He is said rather to have been affected. Thus such conditions

are called affections, not qualities. In like manner there

are affective qualities and affections of the soul.

That temper with which a man is born and which has

its origin in certain deep-seated affections is called a quality. I mean

such conditions as insanity, irascibility, and so on: for people are said to

be mad or irascible in virtue of these. Similarly those abnormal psychic

states which are not inborn, but arise from the concomitance of

certain other elements, and are difficult to remove, or altogether permanent,

are called qualities, for in virtue of them men are said to be such and such.

Those, however, which arise from causes easily rendered ineffective are called affections, not qualities.

Suppose that a man is irritable when vexed: he is not even spoken

of as a bad-tempered man, when in such circumstances he loses his temper somewhat, but rather

is said to be affected. Such conditions are therefore termed, not qualities,

but affections.

The fourth sort of quality is figure and the shape

that belongs to a thing; and besides this, straightness and

curvedness and any other qualities of this type; each of these

defines a thing as being such and such. Because it is triangular or quadrangular

a thing is said to have a specific character, or again because it is straight or curved;

in fact a thing's shape in every case gives rise to a qualification of it. Rarity

and density, roughness and smoothness, seem to be terms indicating

quality: yet these, it would appear, really belong to a

class different from that of quality. For it is rather a certain relative position of the

parts composing the thing thus qualified which, it appears, is indicated by each of these terms. A thing is dense, owing to

the fact that its parts are closely combined with one another; rare, because there are interstices

between the parts; smooth, because its parts lie, so to speak,

evenly; rough, because some parts project beyond others.

There may be other sorts of quality, but those that are most properly

so called have, we may safely say, been enumerated.

These, then, are qualities, and the things that take their name from them as derivatives, or are

in some other way dependent on them, are said to be qualified in some specific way.

In most, indeed in almost all cases, the name of

that which is qualified is derived from that of the

quality. Thus the terms 'whiteness', 'grammar', 'justice', give us the adjectives

'white', 'grammatical', 'just', and so on. There are some cases, however, in

which, as the quality under consideration has no name, it is impossible that those possessed of it

should have a name that is derivative. For instance, the name given to the runner

or boxer, who is so called in virtue of an inborn capacity, is not derived from

that of any quality; for lob those capacities have no name assigned to them. In

this, the inborn capacity is distinct from the science, with reference to which men are called, e.g.

boxers or wrestlers. Such a science is classed as a disposition; it has a name, and

is called 'boxing' or 'wrestling' as the case may be, and the name given to those

disposed in this way is derived from that of the science. Sometimes, even though a

name exists for the quality, that which takes its character from

the quality has a name that is not a derivative. For instance, the

upright man takes his character from the possession of the quality of integrity, but the name given him is not derived

from the word 'integrity'. Yet this does not occur often. We may therefore state

that those things are said to be possessed of some specific quality which have a name derived from that of the aforesaid quality,

or which are in some other way dependent on it.

One quality may be the contrary of another; thus justice is the contrary of injustice, whiteness

of blackness, and so on. The things, also, which are said to be such and such in virtue of

these qualities, may be contrary the one to the other; for that which is unjust is contrary to

that which is just, that which is white to that which is black. This, however, is

not always the case. Red, yellow, and such colours,

though qualities, have no contraries. If one

of two contraries is a quality, the other will also be a quality. This

will be evident from particular instances, if we apply the names used to denote the other categories;

for instance, granted that justice is the contrary of injustice and justice is a quality, injustice

will also be a quality: neither quantity, nor relation, nor

place, nor indeed any other category but that

of quality, will be applicable properly to injustice.

So it is with all other contraries falling under the category of

quality.

Qualities admit of variation of degree.

Whiteness is predicated of one thing in a greater or less degree than of another. This

is also the case with reference to justice. Moreover, one and the same thing may exhibit a

quality in a greater degree than it did before: if a thing is white, it may become whiter. Though

this is generally the case, there are exceptions. For if we should say that justice admitted

of variation of degree, difficulties might ensue, and this is true with regard to

all those qualities which are dispositions. There are some, indeed, who dispute the possibility

of variation here. They maintain that justice and health cannot very

well admit of variation of degree themselves, but that people vary in

the degree in which they possess these qualities, and that this is

the case with grammatical learning and all those qualities which are classed

as dispositions. However that may be, it is an incontrovertible fact that the things which in virtue of these

qualities are said to be what they are vary in the degree in which they possess them; for one

man is said to be better versed in grammar, or more healthy

or just, than another, and so on. The qualities expressed by the

terms 'triangular' and 'quadrangular' do not appear to admit of variation of degree, nor indeed do any that

have to do with figure. For those things to which the definition of the

triangle or circle is applicable are all equally triangular or circular. Those, on the other

hand, to which the same definition is not applicable, cannot be said to differ from

one another in degree; the square is no more a circle

than the rectangle, for to neither is the definition of the circle appropriate.

In short, if the definition of the term proposed

is not applicable to both objects, they cannot be compared.

Thus it is not all qualities which admit of variation of degree.

Whereas none of the characteristics I have mentioned are peculiar to quality, the fact that likeness and unlikeness can

be predicated with reference to quality only, gives to that category its distinctive feature. One thing

is like another only with reference to that in virtue of which it is such and

such; thus this forms the peculiar mark of

quality.

We must not be disturbed because it may be argued that, though

proposing to discuss the category of quality, we have included in it

many relative terms. We did say that habits and dispositions were

relative. In practically all such cases the genus

is relative, the individual not. Thus knowledge, as

a genus, is explained by reference to something else, for we mean a

knowledge of something. But particular branches of knowledge are not thus

explained. The knowledge of grammar is not relative to anything external, nor

is the knowledge of music, but these, if relative at all, are

relative only in virtue of their genera; thus grammar is

said be the knowledge of something, not the grammar of something; similarly music

is the knowledge of something, not the music of something. Thus

individual branches of knowledge are not relative. And it is because we possess these individual branches of

knowledge that we are said to be such and such. It is these that we actually possess: we are

called experts because we possess knowledge in some particular branch. Those particular

branches, therefore, of knowledge, in virtue of which we are sometimes said

to be such and such, are themselves qualities, and are not relative.

Further, if anything should happen to fall within both the category of quality and that of relation,

there would be nothing extraordinary in classing it under both these heads.

Action and affection both admit of contraries and also

of variation of degree. Heating is the

contrary of cooling, being heated of being cooled, being glad

of being vexed. Thus they admit of contraries. They

also admit of variation of degree: for it is possible to heat

in a greater or less degree; also to be heated in a greater

or less degree. Thus action and affection also admit of

variation of degree.

So much, then, is stated with regard to these categories. We spoke, moreover, of the category of position when we were dealing

with that of relation, and stated that such terms derived their names from those of the corresponding attitudes. As for the rest,

time, place, state, since they are easily intelligible, I say no more about them than

was said at the beginning, that in the category of state are included such states

as 'shod', 'armed', in that of place 'in the Lyceum' and so on, as

was explained before. The proposed categories have, then, been adequately dealt with.

We must next explain the various senses in which the term 'opposite' is used.

Things are said to be opposed in four senses: (i) as correlatives

to one another, (ii) as contraries to one another, (iii) as privatives to

positives, (iv) as affirmatives to negatives. Let me sketch my meaning in outline.

An instance of the use of the word 'opposite' with reference to correlatives is afforded

by the expressions 'double' and 'half'; with reference to contraries by 'bad' and 'good'. Opposites

in the sense of 'privatives' and 'positives' are' blindness' and 'sight'; in the

sense of affirmatives and negatives, the propositions 'he sits', 'he does not sit'.

(i) Pairs of opposites which fall under the category of relation are explained by a reference of the

one to the other, the reference being indicated by the preposition 'of' or by some other preposition.

Thus, double is a relative term, for that which is double is explained as the double of

something. Knowledge, again, is the opposite of

the thing known, in the same sense;

and the thing known also is explained by

its relation to its opposite, knowledge. For the thing known is explained as that

which is known by something, that is, by knowledge.

Such things, then, as are opposite the one to the other in the sense of being correlatives

are explained by a reference of the one to the other. (ii) Pairs

of opposites which are contraries are not in any way interdependent, but

are contrary the one to the other. The good is not spoken

of as the good of the had, but as the contrary of the bad, nor is white spoken of as the

white of the black, but as the contrary of the black. These two types of opposition

are therefore distinct. Those contraries which are such that the subjects in

which they are naturally present, or of which they are predicated, must necessarily

contain either the one or the other of them, have no intermediate, but those

in the case of which no such necessity obtains, always have an

intermediate. Thus disease and health are naturally present in the body of an

animal, and it is necessary that either the one or the other should be present

in the body of an animal. Odd and even, again, are predicated of

number, and it is necessary that the one or the other

should be present in numbers. Now there is no intermediate

between the terms of either of these two pairs. On

the other hand, in those contraries with regard to which no such necessity obtains, we find an

intermediate. Blackness and whiteness are naturally present in the body, but it is not necessary that

either the one or the other should be present in the body, inasmuch as it is not

true to say that everybody must be white or black. Badness and goodness, again, are

predicated of man, and of many other things, but it is not necessary

that either the one quality or the other should be present in that

of which they are predicated: it is not true to say that everything that may be good or bad must

be either good or bad. These pairs of contraries have intermediates: the intermediates between white and

black are grey, sallow, and all the other colours that come between; the

intermediate between good and bad is that which is neither the one nor the

other. Some intermediate qualities have names, such as grey and sallow and all

the other colours that come between white and black; in other cases,

however, it is not easy to name the intermediate, but we must define

it as that which is not either extreme, as in the

case of that which is neither good nor bad, neither just nor

unjust.

(iii) 'privatives' and 'Positives' have reference to the same subject. Thus, sight

and blindness have reference to the eye. It is a universal rule that each

of a pair of opposites of this type has reference to that to which the particular 'positive' is

natural. We say that that is capable of some particular faculty or possession has suffered privation when the

faculty or possession in question is in no way present in that in which, and at the time at

which, it should naturally be present. We do not call that toothless which has not teeth,

or that blind which has not sight, but rather that which has not teeth or sight at the

time when by nature it should. For there are some creatures which from birth are

without sight, or without teeth, but these are not called toothless or blind.

To be without some faculty or to possess it is not the same as the corresponding 'privative' or

'positive'. 'Sight' is a 'positive', 'blindness' a 'privative', but 'to possess sight'

is not equivalent to 'sight', 'to be blind' is not equivalent to

'blindness'. Blindness is a 'privative', to be blind is to be in a

state of privation, but is not a 'privative'. Moreover, if 'blindness' were equivalent

to 'being blind', both would be predicated of the same

subject; but though a man is said to be blind, he is by

no means said to be blindness. To be in a state of 'possession' is,

it appears, the opposite of being in a state of 'privation', just as 'positives' and 'privatives' themselves are

opposite. There is the same type of antithesis in both cases; for just

as blindness is opposed to sight, so is being blind opposed

to having sight. That which is affirmed or denied is

not itself affirmation or denial. By 'affirmation' we mean

an affirmative proposition, by 'denial' a negative. Now, those facts which

form the matter of the affirmation or denial are not propositions;

yet these two are said to be opposed in the same sense as the affirmation and denial, for in this case

also the type of antithesis is the same. For as the affirmation is opposed to the denial, as in the two

propositions 'he sits', 'he does not sit', so also the fact which constitutes the

matter of the proposition in one case is opposed to that in

the other, his sitting, that is to say, to his not

sitting. It is evident that 'positives' and 'privatives' are not opposed each to each in

the same sense as relatives. The one is not explained by reference to the

other; sight is not sight of blindness, nor is any other preposition

used to indicate the relation. Similarly blindness is not

said to be blindness of sight,

but rather, privation of sight. Relatives, moreover,

reciprocate; if blindness, therefore, were a relative, there would be a

reciprocity of relation between it and that with which it was

correlative. But this is not the case. Sight is not called the

sight of blindness.

That those terms which fall under the heads of 'positives' and 'privatives' are not opposed each

to each as contraries, either, is plain from the following facts: Of a pair of

contraries such that they have no intermediate, one or the other must needs be present

in the subject in which they naturally subsist, or of which they are predicated;

for it is those, as we proved,' in the case of which this necessity

obtains, that have no intermediate. Moreover, we cited health and disease, odd and even,

as instances. But those contraries which have an intermediate are not subject to

any such necessity. It is not necessary that every substance, receptive of such

qualities, should be either black or white, cold or hot, for something intermediate between these

contraries may very well be present in the subject. We proved, moreover, that those

contraries have an intermediate in the case of which the said necessity does not obtain. Yet when

one of the two contraries is a constitutive property of the subject, as it is a

constitutive property of fire to be hot, of snow to be white, it is

necessary determinately that one of the two contraries, not one or the other, should be present

in the subject; for fire cannot be cold, or

snow black. Thus, it is not the case here that one of the

two must needs be present in every subject receptive of these qualities, but only in that subject of which the one

forms a constitutive property. Moreover, in such cases it is one member of the pair determinately, and not either the one or

the other, which must be present. In the case of 'positives' and 'privatives', on the other hand,

neither of the aforesaid statements holds good. For it is not necessary that a subject receptive

of the qualities should always have either the one or the other; that which has not yet

advanced to the state when sight is natural is not said either to be blind or to see. Thus 'positives'

and 'privatives' do not belong to that class of contraries which consists of those which have no intermediate.

On the other hand, they do not belong either to that class which consists of contraries which have an intermediate. For under certain conditions it is necessary that either the

one or the other should form part of the constitution of every appropriate subject. For when a thing has reached

the stage when it is by nature capable of sight, it will be said either to see or to be blind,

and that in an indeterminate sense, signifying that the capacity may be either present or absent; for it is not necessary either

that it should see or that it should be blind, but that it should be either in the one state

or in the other. Yet in the case of those contraries which have an intermediate we found that it was never necessary

that either the one or the other should be present in every appropriate subject, but only that in certain subjects one of

the pair should be present, and that in a determinate sense. It is, therefore, plain that 'positives' and

'privatives' are not opposed each to each in either of the senses in which

contraries are opposed. Again, in the case of contraries, it is possible that there should

be changes from either into the other, while the subject retains its identity, unless indeed one

of the contraries is a constitutive property of that subject, as heat is of fire. For it

is possible that that that which is healthy should become diseased, that

which is white, black, that which is cold, hot, that which is good,

bad, that which is bad, good. The bad man, if he

is being brought into a better way of life and thought, may

make some advance, however slight, and if he should once improve, even ever

so little, it is plain that he might change completely, or at any rate make

very great progress; for a man becomes more and more easily moved to virtue, however small the

improvement was at first. It is, therefore, natural to suppose that he will make yet greater progress

than he has made in the past; and as this process goes on, it will

change him completely and establish him in the contrary state, provided he is not hindered by lack

of time. In the case of 'positives' and 'privatives', however, change

in both directions is impossible. There may be a

change from possession to privation, but not from

privation to possession. The man who has become blind does not regain

his sight; the man who has become bald does not regain his hair; the man who has lost his teeth

does not grow his grow a new set.

(iv) Statements opposed as affirmation and negation belong

manifestly to a class which is distinct,

for in this case, and in this case only, it is necessary for the one opposite to be

true and the other false. Neither in the case of contraries, nor in the

case of correlatives, nor in the case of 'positives' and 'privatives', is it necessary

for one to be true and the other false. Health and

disease are contraries: neither of them is true or false.

'Double' and 'half' are opposed to each other

as correlatives: neither of them is true or false.

The case is the same, of course, with regard to 'positives' and 'privatives' such as 'sight'

and 'blindness'. In short, where there is no sort of combination of

words, truth and falsity have no place, and all the opposites we

have mentioned so far consist of simple words. At the same time, when the

words which enter into opposed statements are contraries, these, more than any other set of opposites,

would seem to claim this characteristic. 'Socrates is ill' is the contrary of 'Socrates is

well', but not even of such composite expressions is it true to say that one

of the pair must always be true and the other false. For if Socrates exists,

one will be true and the other false, but if he does not exist, both

will be false; for neither 'Socrates is ill' nor 'Socrates is

well' is true, if Socrates does not exist at all.

In the case of 'positives' and 'privatives', if the subject does not exist at all, neither proposition is true, but

even if the subject exists, it is not always the fact that one is true and the other false.

For 'Socrates has sight' is the opposite of 'Socrates is blind' in

the sense of the word 'opposite' which applies to possession and privation.

Now if Socrates exists, it is not necessary that one should

be true and the other false, for when he is not yet

able to acquire the power of vision, both are false, as also

if Socrates is altogether non-existent. But in the case of

affirmation and negation, whether the subject exists or not, one is

always false and the other true. For manifestly, if Socrates

exists, one of the two propositions 'Socrates is ill', 'Socrates

is not ill', is true, and the other false.

This is likewise the case if he does not exist; for if he does not exist, to say that he is ill is false, to say that he is not ill

is true. Thus it is in the case of those opposites only, which are opposite in the sense in which the term

is used with reference to affirmation and negation, that the rule holds good, that one of the pair must be

true and the other false.

That the contrary of a good is an evil is

shown by induction: the contrary of health is disease, of courage,

cowardice, and so on. But the contrary of an evil

is sometimes a good, sometimes an evil. For defect, which is an

evil, has excess for its contrary, this also being an evil, and the mean, which is a

good, is equally the contrary of the one and of the other. It is only in a

few cases, however, that we see instances of this: in most, the contrary of

an evil is a good. In the case of contraries, it is not always necessary that

if one exists the other should also exist: for if all become healthy there will be

health and no disease, and again, if everything turns white,

there will be white, but no black. Again, since the fact that

Socrates is ill is the contrary of the fact that Socrates is well, and two

contrary conditions cannot both obtain in one and the same individual at the same time,

both these contraries could not exist at once: for if that Socrates was well was

a fact, then that Socrates was ill could not possibly be one.

It is plain that contrary attributes must needs be present in subjects which belong to

the same species or genus. Disease and health require as their subject the body of an animal;

white and black require a body, without further qualification; justice and injustice require as their subject

the human soul. Moreover, it is necessary that pairs of contraries should in all cases either

belong to the same genus or belong to contrary genera or be themselves genera. White

and black belong to the same genus, colour;

justice and injustice, to contrary genera, virtue and vice;

while good and evil do not belong to

genera, but are themselves actual genera, with terms under

them.

There are four senses in which one thing can be said to be 'prior' to another. Primarily and most

properly the term has reference to time: in this sense the word

is used to indicate that one thing is older or more ancient than another, for the

expressions 'older' and 'more ancient' imply greater length of time. Secondly, one

thing is said to be 'prior' to another when the sequence of their

being cannot be reversed. In this sense 'one' is 'prior' to 'two'. For

if 'two' exists, it follows directly that 'one' must exist, but if 'one' exists, it does

not follow necessarily that 'two' exists: thus the sequence subsisting cannot be reversed. It is agreed, then,

that when the sequence of two things cannot be reversed, then that one on which the

other depends is called 'prior' to that other. In the third place, the term 'prior' is

used with reference to any order, as in the case of science and of oratory.

For in sciences which use demonstration there is that which is prior

and that which is posterior in order; in geometry, the elements are

prior to the propositions; in reading and writing, the letters of the

alphabet are prior to the syllables. Similarly, in the case of speeches,

the exordium is prior in order to the narrative. Besides these

senses of the word, there is a fourth. That which is better and more honourable is

said to have a natural priority. In common parlance men speak of

those whom they honour and love as 'coming

first' with them. This sense of the word is perhaps

the most far-fetched.

Such, then, are the different senses in which the term 'prior' is used.

Yet it would seem that besides those mentioned there

is yet another. For in those things, the being of each of which implies

that of the other, that which is in any way the cause may reasonably be said

to be by nature 'prior' to the effect. It is plain that there are instances of

this. The fact of the being of a man carries with it the truth

of the proposition that he is, and the implication is reciprocal: for if

a man is, the proposition wherein we allege that he is true,

and conversely, if the proposition wherein we allege that

he is true, then he is. The true proposition, however, is

in no way the cause of the being of the man, but the fact of the man's

being does seem somehow to be the cause of the truth of the proposition,

for the truth or falsity of the proposition depends on the fact of the man's being

or not being. Thus the word 'prior' may be used in five

senses.

The term 'simultaneous' is primarily and most appropriately applied to those things the genesis of the one of

which is simultaneous with that of the other; for in such cases neither is prior or posterior

to the other. Such things are said to be simultaneous in point of time.

Those things, again, are 'simultaneous' in point of nature, the being of

each of which involves that of the other, while at the same

time neither is the cause of the other's being. This is the case with regard

to the double and the half, for these are reciprocally dependent, since, if there is a double, there is also a half,

and if there is a half, there is also a double, while at the same time neither is the cause of the

being of the other. Again, those species which are distinguished one from another and opposed one to another within the

same genus are said to be 'simultaneous' in nature. I mean those species which are distinguished each

from each by one and the same method of division. Thus the 'winged' species is simultaneous with the

'terrestrial' and the 'water' species. These are distinguished within the same genus, and are

opposed each to each, for the genus 'animal' has the 'winged', the 'terrestrial',

and the 'water' species, and no one of these is prior or

posterior to another; on the contrary, all such things appear to be

'simultaneous' in nature. Each of these also, the terrestrial, the

winged, and the water species, can be divided again into

subspecies. Those species, then, also will be 'simultaneous' point of nature, which, belonging to the same genus, are

distinguished each from each by one and the same method of differentiation. But genera are prior

to species, for the sequence of their being cannot be

reversed. If there is the species 'water-animal', there will be the genus 'animal', but granted the being of the genus 'animal', it

does not follow necessarily that there will be the species 'water-animal'. Those things, therefore, are said to be 'simultaneous' in

nature, the being of each of which involves that of the other, while at the same time

neither is in any way the cause of the other's being; those species, also, which are distinguished each

from each and opposed within the same genus. Those things, moreover, are 'simultaneous' in the unqualified sense of the word which come

into being at the same time.

There are six sorts of movement: generation, destruction, increase, diminution,

alteration, and change of place. It is evident in all but

one case that all these sorts of movement are distinct each from each. Generation is distinct

from destruction, increase and change of place from

diminution, and so on. But in the case of alteration

it may be argued that the process necessarily implies one or other of the

other five sorts of motion. This is not true, for we

may say that all affections, or nearly all, produce in us an

alteration which is distinct from all other sorts of motion, for

that which is affected need not suffer either increase or

diminution or any of the other sorts of motion. Thus alteration

is a distinct sort of motion; for, if it were

not, the thing altered would not only be altered, but would forthwith necessarily suffer increase or diminution or

some one of the other sorts of motion in addition; which as a matter of fact is not the case.

Similarly that which was undergoing the process of increase or was subject to some other sort of motion would, if alteration were not a

distinct form of motion, necessarily be subject to alteration also. But there are some things which undergo increase but yet

not alteration. The square, for instance, if a gnomon is applied

to it, undergoes increase but not alteration, and so it is

with all other figures of this sort. Alteration and increase, therefore, are

distinct.

Speaking generally, rest is the contrary of motion. But the different

forms of motion have their own contraries in other forms; thus destruction is the contrary of generation, diminution of increase,

rest in a place, of change of place. As for this last,

change in the reverse direction would seem to be most truly its contrary;

thus motion upwards is the contrary of motion downwards and vice versa.

In the case of that sort of motion which yet

remains, of those that have been enumerated, it is not easy to state

what is its contrary. It appears to have no contrary, unless one should

define the contrary here also either as 'rest in its quality' or as

'change in the direction of the contrary quality', just as we

defined the contrary of change of place either as rest in a place

or as change in the reverse direction. For a thing is

altered when change of quality takes place; therefore either rest in its quality or change in the

direction of the contrary may be called the contrary of this qualitative form of motion. In this way

becoming white is the contrary of becoming black; there is alteration in the contrary direction, since

a change of a qualitative nature takes place.

The term 'to have' is used in various senses. In the

first place it is used with reference to habit or disposition or any other quality, for

we are said to 'have' a piece of knowledge or a virtue. Then, again, it has

reference to quantity, as, for instance, in the case of a man's height; for he is said to

'have' a height of three or four cubits. It is used, moreover, with regard to apparel, a man

being said to 'have' a coat or tunic; or in respect of something which we have on a part of ourselves, as a

ring on the hand: or in respect of something which is a part of us, as hand or foot. The term refers also

to content, as in the case of a vessel and wheat, or of a jar

and wine; a jar is said to 'have' wine, and a corn-measure wheat.

The expression in such cases has reference to content. Or it refers to that which has been acquired;

we are said to 'have' a house or a field. A man is also said

to 'have' a wife, and a wife a husband, and this appears to be the most

remote meaning of the term, for by the use of it we mean

simply that the husband lives with the wife. Other senses of the word

might perhaps be found, but the most ordinary ones have

all been enumerated.