Some of Aristotle's works

THE ATHENIAN CONSTITUTION

CATEGORIES

by Aristotle

translated by E. M. Edghill

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 every.

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 sub. stance 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 arts

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 '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.

-THE END-

350 BC

ON DREAMS

by Aristotle

translated by J. I. Beare

WE must, in the next place, investigate the subject of the dream,

and first inquire to which of the faculties of the soul it presents

itself, i.e. whether the affection is one which pertains to the

faculty of intelligence or to that of sense-perception; for these

are the only faculties within us by which we acquire knowledge.

If, then, the exercise of the faculty of sight is actual seeing,

that of the auditory faculty, hearing, and, in general that of the

faculty of sense-perception, perceiving; and if there are some

perceptions common to the senses, such as figure, magnitude, motion,

&c., while there are others, as colour, sound, taste, peculiar [each

to its own sense]; and further, if all creatures, when the eyes are

closed in sleep, are unable to see, and the analogous statement is

true of the other senses, so that manifestly we perceive nothing

when asleep; we may conclude that it is not by sense-perception we

perceive a dream.

But neither is it by opinion that we do so. For [in dreams] we not

only assert, e.g. that some object approaching is a man or a horse

[which would be an exercise of opinion], but that the object is

white or beautiful, points on which opinion without sense-perception

asserts nothing either truly or falsely. It is, however, a fact that

the soul makes such assertions in sleep. We seem to see equally well

that the approaching figure is a man, and that it is white. [In

dreams], too, we think something else, over and above the dream

presentation, just as we do in waking moments when we perceive

something; for we often also reason about that which we perceive.

So, too, in sleep we sometimes have thoughts other than the mere

phantasms immediately before our minds. This would be manifest to

any one who should attend and try, immediately on arising from

sleep, to remember [his dreaming experience]. There are cases of

persons who have seen such dreams, those, for example, who believe

themselves to be mentally arranging a given list of subjects according

to the mnemonic rule. They frequently find themselves engaged in

something else besides the dream, viz. in setting a phantasm which

they envisage into its mnemonic position. Hence it is plain that not

every 'phantasm' in sleep is a mere dream-image, and that the

further thinking which we perform then is due to an exercise of the

faculty of opinion.

So much at least is plain on all these points, viz. that the faculty

by which, in waking hours, we are subject to illusion when affected by

disease, is identical with that which produces illusory effects in

sleep. So, even when persons are in excellent health, and know the

facts of the case perfectly well, the sun, nevertheless, appears to

them to be only a foot wide. Now, whether the presentative faculty

of the soul be identical with, or different from, the faculty of

sense-perception, in either case the illusion does not occur without

our actually seeing or [otherwise] perceiving something. Even to see

wrongly or to hear wrongly can happen only to one who sees or hears

something real, though not exactly what he supposes. But we have

assumed that in sleep one neither sees, nor hears, nor exercises any

sense whatever. Perhaps we may regard it as true that the dreamer sees

nothing, yet as false that his faculty of sense-perception is

unaffected, the fact being that the sense of seeing and the other

senses may possibly be then in a certain way affected, while each of

these affections, as duly as when he is awake, gives its impulse in

a certain manner to his [primary] faculty of sense, though not in

precisely the same manner as when he is awake. Sometimes, too, opinion

says [to dreamers] just as to those who are awake, that the object

seen is an illusion; at other times it is inhibited, and becomes a

mere follower of the phantasm.

It is plain therefore that this affection, which we name 'dreaming',

is no mere exercise of opinion or intelligence, but yet is not an

affection of the faculty of perception in the simple sense. If it were

the latter it would be possible [when asleep] to hear and see in the

simple sense.

How then, and in what manner, it takes place, is what we have to

examine. Let us assume, what is indeed clear enough, that the

affection [of dreaming] pertains to sense-perception as surely as

sleep itself does. For sleep does not pertain to one organ in

animals and dreaming to another; both pertain to the same organ.

But since we have, in our work On the Soul, treated of presentation,

and the faculty of presentation is identical with that of

sense-perception, though the essential notion of a faculty of

presentation is different from that of a faculty of

sense-perception; and since presentation is the movement set up by a

sensory faculty when actually discharging its function, while a

dream appears to be a presentation (for a presentation which occurs in

sleep-whether simply or in some particular way-is what we call a

dream): it manifestly follows that dreaming is an activity of the

faculty of sense-perception, but belongs to this faculty qua

presentative.

We can best obtain a scientific view of the nature of the dream

and the manner in which it originates by regarding it in the light

of the circumstances attending sleep. The objects of

sense-perception corresponding to each sensory organ produce

sense-perception in us, and the affection due to their operation is

present in the organs of sense not only when the perceptions are

actualized, but even when they have departed.

What happens in these cases may be compared with what happens in the

case of projectiles moving in space. For in the case of these the

movement continues even when that which set up the movement is no

longer in contact [with the things that are moved]. For that which set

them in motion moves a certain portion of air, and this, in turn,

being moved excites motion in another portion; and so, accordingly, it

is in this way that [the bodies], whether in air or in liquids,

continue moving, until they come to a standstill.

This we must likewise assume to happen in the case of qualitative

change; for that part which [for example] has been heated by something

hot, heats [in turn] the part next to it, and this propagates the

affection continuously onwards until the process has come round to its

oint of origination. This must also happen in the organ wherein the

exercise of sense-perception takes place, since sense-perception, as

realized in actual perceiving, is a mode of qualitative change. This

explains why the affection continues in the sensory organs, both in

their deeper and in their more superficial parts, not merely while

they are actually engaged in perceiving, but even after they have

ceased to do so. That they do this, indeed, is obvious in cases

where we continue for some time engaged in a particular form of

perception, for then, when we shift the scene of our perceptive

activity, the previous affection remains; for instance, when we have

turned our gaze from sunlight into darkness. For the result of this is

that one sees nothing, owing to the excited by the light still

subsisting in our eyes. Also, when we have looked steadily for a

long while at one colour, e.g. at white or green, that to which we

next transfer our gaze appears to be of the same colour. Again if,

after having looked at the sun or some other brilliant object, we

close the eyes, then, if we watch carefully, it appears in a right

line with the direction of vision (whatever this may be), at first

in its own colour; then it changes to crimson, next to purple, until

it becomes black and disappears. And also when persons turn away

from looking at objects in motion, e.g. rivers, and especially those

which flow very rapidly, they find that the visual stimulations

still present themselves, for the things really at rest are then

seen moving: persons become very deaf after hearing loud noises, and

after smelling very strong odours their power of smelling is impaired;

and similarly in other cases. These phenomena manifestly take place in

the way above described.

That the sensory organs are acutely sensitive to even a slight

qualitative difference [in their objects] is shown by what happens

in the case of mirrors; a subject to which, even taking it

independently, one might devote close consideration and inquiry. At

the same time it becomes plain from them that as the eye [in seeing]

is affected [by the object seen], so also it produces a certain effect

upon it. If a woman chances during her menstrual period to look into a

highly polished mirror, the surface of it will grow cloudy with a

blood-coloured haze. It is very hard to remove this stain from a new

mirror, but easier to remove from an older mirror. As we have said

before, the cause of this lies in the fact that in the act of sight

there occurs not only a passion in the sense organ acted on by the

polished surface, but the organ, as an agent, also produces an action,

as is proper to a brilliant object. For sight is the property of an

organ possessing brilliance and colour. The eyes, therefore, have

their proper action as have other parts of the body. Because it is

natural to the eye to be filled with blood-vessels, a woman's eyes,

during the period of menstrual flux and inflammation, will undergo a

change, although her husband will not note this since his seed is of

the same nature as that of his wife. The surrounding atmosphere,

through which operates the action of sight, and which surrounds the

mirror also, will undergo a change of the same sort that occurred

shortly before in the woman's eyes, and hence the surface of the

mirror is likewise affected. And as in the case of a garment, the

cleaner it is the more quickly it is soiled, so the same holds true in

the case of the mirror. For anything that is clean will show quite

clearly a stain that it chances to receive, and the cleanest object

shows up even the slightest stain. A bronze mirror, because of its

shininess, is especially sensitive to any sort of contact (the

movement of the surrounding air acts upon it like a rubbing or

pressing or wiping); on that account, therefore, what is clean will

show up clearly the slightest touch on its surface. It is hard to

cleanse smudges off new mirrors because the stain penetrates deeply

and is suffused to all parts; it penetrates deeply because the

mirror is not a dense medium, and is suffused widely because of the

smoothness of the object. On the other hand, in the case of old

mirrors, stains do not remain because they do not penetrate deeply,

but only smudge the surface.

From this therefore it is plain that stimulatory motion is set up

even by slight differences, and that sense-perception is quick to

respond to it; and further that the organ which perceives colour is

not only affected by its object, but also reacts upon it. Further

evidence to the same point is afforded by what takes place in wines,

and in the manufacture of unguents. For both oil, when prepared, and

wine become rapidly infected by the odours of the things near them;

they not only acquire the odours of the things thrown into or mixed

with them, but also those of the things which are placed, or which

grow, near the vessels containing them.

In order to answer our original question, let us now, therefore,

assume one proposition, which is clear from what precedes, viz. that

even when the external object of perception has departed, the

impressions it has made persist, and are themselves objects of

perception: and [let us assume], besides, that we are easily

deceived respecting the operations of sense-perception when we are

excited by emotions, and different persons according to their

different emotions; for example, the coward when excited by fear,

the amorous person by amorous desire; so that, with but little

resemblance to go upon, the former thinks he sees his foes

approaching, the latter, that he sees the object of his desire; and

the more deeply one is under the influence of the emotion, the less

similarity is required to give rise to these illusory impressions.

Thus too, both in fits of anger, and also in all states of appetite,

all men become easily deceived, and more so the more their emotions

are excited. This is the reason too why persons in the delirium of

fever sometimes think they see animals on their chamber walls, an

illusion arising from the faint resemblance to animals of the markings

thereon when put together in patterns; and this sometimes

corresponds with the emotional states of the sufferers, in such a

way that, if the latter be not very ill, they know well enough that it

is an illusion; but if the illness is more severe they actually move

according to the appearances. The cause of these occurrences is that

the faculty in virtue of which the controlling sense judges is not

identical with that in virtue of which presentations come before the

mind. A proof of this is, that the sun presents itself as only a

foot in diameter, though often something else gainsays the

presentation. Again, when the fingers are crossed, the one object

[placed between them] is felt [by the touch] as two; but yet we deny

that it is two; for sight is more authoritative than touch. Yet, if

touch stood alone, we should actually have pronounced the one object

to be two. The ground of such false judgements is that any appearances

whatever present themselves, not only when its object stimulates a

sense, but also when the sense by itself alone is stimulated, provided

only it be stimulated in the same manner as it is by the object. For

example, to persons sailing past the land seems to move, when it is

really the eye that is being moved by something else [the moving ship.]

From this it is manifest that the stimulatory movements based upon

sensory impressions, whether the latter are derived from external

objects or from causes within the body, present themselves not only

when persons are awake, but also then, when this affection which is

called sleep has come upon them, with even greater impressiveness. For

by day, while the senses and the intellect are working together,

they (i.e. such movements) are extruded from consciousness or

obscured, just as a smaller is beside a larger fire, or as small

beside great pains or pleasures, though, as soon as the latter have

ceased, even those which are trifling emerge into notice. But by night

[i.e. in sleep] owing to the inaction of the particular senses, and

their powerlessness to realize themselves, which arises from the

reflux of the hot from the exterior parts to the interior, they

[i.e. the above 'movements'] are borne in to the head quarters of

sense-perception, and there display themselves as the disturbance

(of waking life) subsides. We must suppose that, like the little

eddies which are being ever formed in rivers, so the sensory movements

are each a continuous process, often remaining like what they were

when first started, but often, too, broken into other forms by

collisions with obstacles. This [last mentioned point], moreover,

gives the reason why no dreams occur in sleep immediately after meals,

or to sleepers who are extremely young, e.g. to infants. The

internal movement in such cases is excessive, owing to the heat

generated from the food. Hence, just as in a liquid, if one vehemently

disturbs it, sometimes no reflected image appears, while at other

times one appears, indeed, but utterly distorted, so as to seem

quite unlike its original; while, when once the motion has ceased, the

reflected images are clear and plain; in the same manner during

sleep the phantasms, or residuary movements, which are based upon

the sensory impressions, become sometimes quite obliterated by the

above described motion when too violent; while at other times the

sights are indeed seen, but confused and weird, and the dreams

[which then appear] are unhealthy, like those of persons who are

atrabilious, or feverish, or intoxicated with wine. For all such

affections, being spirituous, cause much commotion and disturbance. In

sanguineous animals, in proportion as the blood becomes calm, and as

its purer are separated from its less pure elements, the fact that the

movement, based on impressions derived from each of the organs of

sense, is preserved in its integrity, renders the dreams healthy,

causes a [clear] image to present itself, and makes the dreamer think,

owing to the effects borne in from the organ of sight, that he

actually sees, and owing to those which come from the organ of

hearing, that he really hears; and so on with those also which proceed

from the other sensory organs. For it is owing to the fact that the

movement which reaches the primary organ of sense comes from them,

that one even when awake believes himself to see, or hear, or

otherwise perceive; just as it is from a belief that the organ of

sight is being stimulated, though in reality not so stimulated, that

we sometimes erroneously declare ourselves to see, or that, from the

fact that touch announces two movements, we think that the one

object is two. For, as a rule, the governing sense affirms the

report of each particular sense, unless another particular sense, more

authoritative, makes a contradictory report. In every case an

appearance presents itself, but what appears does not in every case

seem real, unless when the deciding faculty is inhibited, or does

not move with its proper motion. Moreover, as we said that different

men are subject to illusions, each according to the different

emotion present in him, so it is that the sleeper, owing to sleep, and

to the movements then going on in his sensory organs, as well as to

the other facts of the sensory process, [is liable to illusion], so

that the dream presentation, though but little like it, appears as

some actual given thing. For when one is asleep, in proportion as most

of the blood sinks inwards to its fountain [the heart], the internal

[sensory] movements, some potential, others actual accompany it

inwards. They are so related [in general] that, if anything move the

blood, some one sensory movement will emerge from it, while if this

perishes another will take its place; while to one another also they

are related in the same way as the artificial frogs in water which

severally rise [in fixed succesion] to the surface in the order in

which the salt [which keeps them down] becomes dissolved. The

residuary movements are like these: they are within the soul

potentially, but actualize themselves only when the impediment to

their doing so has been relaxed; and according as they are thus set

free, they begin to move in the blood which remains in the sensory

organs, and which is now but scanty, while they possess verisimilitude

after the manner of cloud-shapes, which in their rapid metamorphoses

one compares now to human beings and a moment afterwards to

centaurs. Each of them is however, as has been said, the remnant of

a sensory impression taken when sense was actualizing itself; and when

this, the true impression, has departed, its remnant is still

immanent, and it is correct to say of it, that though not actually

Koriskos, it is like Koriskos. For when the person was actually

perceiving, his controlling and judging sensory faculty did not call

it Koriskos, but, prompted by this [impression], called the genuine

person yonder Koriskos. Accordingly, this sensory impulse, which, when

actually perceiving, it [the controlling faculty] describes (unless

completely inhibited by the blood), it now [in dreams] when

quasi-perceiving, receives from the movements persisting in the

sense-organs, and mistakes it-an impulse that is merely like the

true [objective] impression-for the true impression itself, while

the effect of sleep is so great that it causes this mistake to pass

unnoticed. Accordingly, just as if a finger be inserted beneath the

eyeball without being observed, one object will not only present two

visual images, but will create an opinion of its being two objects;

while if it [the finger] be observed, the presentation will be the

same, but the same opinion will not be formed of it; exactly so it

is in states of sleep: if the sleeper perceives that he is asleep, and

is conscious of the sleeping state during which the perception comes

before his mind, it presents itself still, but something within him

speaks to this effect: 'the image of Koriskos presents itself, but the

real Koriskos is not present'; for often, when one is asleep, there is

something in consciousness which declares that what then presents

itself is but a dream. If, however, he is not aware of being asleep,

there is nothing which will contradict the testimony of the bare

presentation.

That what we here urge is true, i.e. that there are such

presentative movements in the sensory organs, any one may convince

himself, if he attends to and tries to remember the affections we

experience when sinking into slumber or when being awakened. He will

sometimes, in the moment of awakening, surprise the images which

present themselves to him in sleep, and find that they are really

but movements lurking in the organs of sense. And indeed some very

young persons, if it is dark, though looking with wide open eyes,

see multitudes of phantom figures moving before them, so that they

often cover up their heads in terror.

From all this, then, the conclusion to be drawn is, that the dream

is a sort of presentation, and, more particularly, one which occurs in

sleep; since the phantoms just mentioned are not dreams, nor is any

other a dream which presents itself when the sense-perceptions are

in a state of freedom. Nor is every presentation which occurs in sleep

necessarily a dream. For in the first place, some persons [when

asleep] actually, in a certain way, perceive sounds, light, savour,

and contact; feebly, however, and, as it were, remotely. For there

have been cases in which persons while asleep, but with the eyes

partly open, saw faintly in their sleep (as they supposed) the light

of a lamp, and afterwards, on being awakened, straightway recognized

it as the actual light of a real lamp; while, in other cases,

persons who faintly heard the crowing of cocks or the barking of

dogs identified these clearly with the real sounds as soon as they

awoke. Some persons, too, return answers to questions put to them in

sleep. For it is quite possible that, of waking or sleeping, while the

one is present in the ordinary sense, the other also should be present

in a certain way. But none of these occurrences should be called a

dream. Nor should the true thoughts, as distinct from the mere

presentations, which occur in sleep [be called dreams]. The dream

proper is a presentation based on the movement of sense impressions,

when such presentation occurs during sleep, taking sleep in the strict

sense of the term.

There are cases of persons who in their whole lives have never had a

dream, while others dream when considerably advanced in years,

having never dreamed before. The cause of their not having dreams

appears somewhat like that which operates in the case of infants, and

[that which operates] immediately after meals. It is intelligible

enough that no dream-presentation should occur to persons whose

natural constitution is such that in them copious evaporation is borne

upwards, which, when borne back downwards, causes a large quantity of

motion. But it is not surprising that, as age advances, a dream should

at length appear to them. Indeed, it is inevitable that, as a change

is wrought in them in proportion to age or emotional experience, this

reversal [from non-dreaming to dreaming] should occur also.

THE END

350 BC

ON THE GENERATION OF ANIMALS

by Aristotle

translated by Arthur Platt

Book I

WE have now discussed the other parts of animals, both generally and

with reference to the peculiarities of each kind, explaining how

each part exists on account of such a cause, and I mean by this the

final cause.

There are four causes underlying everything: first, the final cause,

that for the sake of which a thing exists; secondly, the formal cause,

the definition of its essence (and these two we may regard pretty

much as one and the same); thirdly, the material; and fourthly, the

moving principle or efficient cause.

We have then already discussed the other three causes, for the

definition and the final cause are the same, and the material of

animals is their parts of the whole animal the non-homogeneous

parts, of these again the homogeneous, and of these last the so-called

elements of all matter. It remains to speak of those parts which

contribute to the generation of animals and of which nothing

definite has yet been said, and to explain what is the moving or

efficient cause. To inquire into this last and to inquire into the

generation of each animal is in a way the same thing; and,

therefore, my plan has united them together, arranging the

discussion of these parts last, and the beginning of the question of

generation next to them.

Now some animals come into being from the union of male and

female, i.e. all those kinds of animal which possess the two sexes.

This is not the case with all of them; though in the sanguinea with

few exceptions the creature, when its growth is complete, is either

male or female, and though some bloodless animals have sexes so that

they generate offspring of the same kind, yet other bloodless

animals generate indeed, but not offspring of the same kind; such

are all that come into being not from a union of the sexes, but from

decaying earth and excrements. To speak generally, if we take all

animals which change their locality, some by swimming, others by

flying, others by walking, we find in these the two sexes, not only in

the sanguinea but also in some of the bloodless animals; and this

applies in the case of the latter sometimes to the whole class, as the

cephalopoda and crustacea, but in the class of insects only to the

majority. Of these, all which are produced by union of animals of

the same kind generate also after their kind, but all which are not

produced by animals, but from decaying matter, generate indeed, but

produce another kind, and the offspring is neither male nor female;

such are some of the insects. This is what might have been expected,

for if those animals which are not produced by parents had

themselves united and produced others, then their offspring must

have been either like or unlike to themselves. If like, then their

parents ought to have come into being in the same way; this is only

a reasonable postulate to make, for it is plainly the case with

other animals. If unlike, and yet able to copulate, then there would

have come into being again from them another kind of creature and

again another from these, and this would have gone on to infinity. But

Nature flies from the infinite, for the infinite is unending or

imperfect, and Nature ever seeks an end.

But all those creatures which do not move, as the testacea and

animals that live by clinging to something else, inasmuch as their

nature resembles that of plants, have no sex any more than plants

have, but as applied to them the word is only used in virtue of a

similarity and analogy. For there is a slight distinction of this

sort, since even in plants we find in the same kind some trees which

bear fruit and others which, while bearing none themselves, yet

contribute to the ripening of the fruits of those which do, as in

the case of the fig-tree and caprifig.

The same holds good also in plants, some coming into being from seed

and others, as it were, by the spontaneous action of Nature, arising

either from decomposition of the earth or of some parts in other

plants, for some are not formed by themselves separately but are

produced upon other trees, as the mistletoe. Plants, however, must

be investigated separately.

Of the generation of animals we must speak as various questions

arise in order in the case of each, and we must connect our account

with what has been said. For, as we said above, the male and female

principles may be put down first and foremost as origins of

generation, the former as containing the efficient cause of

generation, the latter the material of it. The most conclusive proof

of this is drawn from considering how and whence comes the semen;

for there is no doubt that it is out of this that those creatures

are formed which are produced in the ordinary course of Nature; but we

must observe carefully the way in which this semen actually comes into

being from the male and female. For it is just because the semen is

secreted from the two sexes, the secretion taking place in them and

from them, that they are first principles of generation. For by a male

animal we mean that which generates in another, and by a female that

which generates in itself; wherefore men apply these terms to the

macrocosm also, naming Earth mother as being female, but addressing

Heaven and the Sun and other like entities as fathers, as causing

generation.

Male and female differ in their essence by each having a separate

ability or faculty, and anatomically by certain parts; essentially the

male is that which is able to generate in another, as said above;

the female is that which is able to generate in itself and out of

which comes into being the offspring previously existing in the

parent. And since they are differentiated by an ability or faculty and

by their function, and since instruments or organs are needed for

all functioning, and since the bodily parts are the instruments or

organs to serve the faculties, it follows that certain parts must

exist for union of parents and production of offspring. And these must

differ from each other, so that consequently the male will differ from

the female. (For even though we speak of the animal as a whole as

male or female, yet really it is not male or female in virtue of the

whole of itself, but only in virtue of a certain faculty and a certain

part- just as with the part used for sight or locomotion- which part

is also plain to sense-perception.)

Now as a matter of fact such parts are in the female the so-called

uterus, in the male the testes and the penis, in all the sanguinea;

for some of them have testes and others the corresponding passages.

There are corresponding differences of male and female in all the

bloodless animals also which have this division into opposite sexes.

But if in the sanguinea it is the parts concerned in copulation that

differ primarily in their forms, we must observe that a small change

in a first principle is often attended by changes in other things

depending on it. This is plain in the case of castrated animals,

for, though only the generative part is disabled, yet pretty well

the whole form of the animal changes in consequence so much that it

seems to be female or not far short of it, and thus it is clear than

an animal is not male or female in virtue of an isolated part or an

isolated faculty. Clearly, then, the distinction of sex is a first

principle; at any rate, when that which distinguishes male and

female suffers change, many other changes accompany it, as would be

the case if a first principle is changed.

The sanguinea are not all alike as regards testes and uterus. Taking

the former first, we find that some of them have not testes at all, as

the classes of fish and of serpents, but only two spermatic ducts.

Others have testes indeed, but internally by the loin in the region of

the kidneys, and from each of these a duct, as in the case of those

animals which have no testes at all, these ducts unite also as with

those animals; this applies (among animals breathing air and having a

lung) to all birds and oviparous quadrupeds. For all these have their

testes internal near the loin, and two ducts from these in the same

way as serpents; I mean the lizards and tortoises and all the scaly

reptiles. But all the vivipara have their testes in front; some of

them inside at the end of the abdomen, as the dolphin, not with

ducts but with a penis projecting externally from them; others

outside, either pendent as in man or towards the fundament as in

swine. They have been discriminated more accurately in the Enquiries

about Animals.

The uterus is always double, just as the testes are always two in

the male. It is situated either near the pudendum (as in women, and

all those animals which bring forth alive not only externally but also

internally, and all fish that lay eggs externally) or up towards

the hypozoma (as in all birds and in viviparous fishes). The

uterus is also double in the crustacea and the cephalopoda, for the

membranes which include their so-called eggs are of the nature of a

uterus. It is particularly hard to distinguish in the case of the

poulps, so that it seems to be single, but the reason of this is

that the bulk of the body is everywhere similar.

It is double also in the larger insects; in the smaller the question

is uncertain owing to the small size of the body.

Such is the description of the aforesaid parts of animals.

With regard to the difference of the spermatic organs in males, if

we are to investigate the causes of their existence, we must first

grasp the final cause of the testes. Now if Nature makes everything

either because it is necessary or because it is better so, this part

also must be for one of these two reasons. But that it is not

necessary for generation is plain; else had it been possessed by all

creatures that generate, but as it is neither serpents have testes nor

have fish; for they have been seen uniting and with their ducts full

of milt. It remains then that it must be because it is somehow

better so. Now it is true that the business of most animals is, you

may say, nothing else than to produce young, as the business of a

plant is to produce seed and fruit. But still as, in the case of

nutriment, animals with straight intestines are more violent in

their desire for food, so those which have not testes but only

ducts, or which have them indeed but internally, are all quicker in

accomplishing copulation. But those which are to be more temperate

in the one case have not straight intestines, and in the other have

their ducts twisted to prevent their desire being too violent and

hasty. It is for this that the testes are contrived; for they make the

movement of the spermatic secretion steadier, preserving the folding

back of the passages in the vivipara, as horses and the like, and in

man. (For details see the Enquiries about Animals.) For the testes

are no part of the ducts but are only attached to them, as women

fasten stones to the loom when weaving; if they are removed the

ducts are drawn up internally, so that castrated animals are unable to

generate; if they were not drawn up they would be able, and before now

a bull mounting immediately after castration has caused conception

in the cow because the ducts had not yet been drawn up. In birds and

oviparous quadrupeds the testes receive the spermatic secretion, so

that its expulsion is slower than in fishes. This is clear in the case

of birds, for their testes are much enlarged at the time of

copulation, and all those which pair at one season of the year have

them so small when this is past that they are almost indiscernible,

but during the season they are very large. When the testes are

internal the act of copulation is quicker than when they are external,

for even in the latter case the semen is not emitted before the testes

are drawn up.

Besides, quadrupeds have the organ of copulation, since it is

possible for them to have it, but for birds and the footless animals

it is not possible, because the former have their legs under the

middle of the abdomen and the latter have no legs at all; now the

penis depends from that region and is situated there. (Wherefore also

the legs are strained in intercourse, both the penis and the legs

being sinewy.) So that, since it is not possible for them to have

this organ, they must necessarily either have no testes also, or at

any rate not have them there, as those animals that have both penis

and testes have them in the same situation.

Further, with those animals at any rate that have external testes,

the semen is collected together before emission, and emission is due

to the penis being heated by its movement; it is not ready for

emission at immediate contact as in fishes.

All the vivipira have their testes in front, internally or

externally, except the hedgehog; he alone has them near the loin. This

is for the same reason as with birds, because their union must be

quick, for the hedgehog does not, like the other quadrupeds, mount

upon the back of the female, but they conjugate standing upright

because of their spines.

So much for the reasons why those animals have testes which have

them, and why they are sometimes external and sometimes internal.

All those animals which have no testes are deficient in this part,

as has been said, not because it is better to be so but simply because

of necessity, and secondly because it is necessary that their

copulation should be speedy. Such is the nature of fish and

serpents. Fish copulate throwing themselves alongside of the females

and separating again quickly. For as men and all such creatures must

hold their breath before emitting the semen, so fish at such times

must cease taking in the sea-water, and then they perish easily.

Therefore they must not mature the semen during copulation, as

viviparous land-animals do, but they have it all matured together

before the time, so as not to be maturing it while in contact but to

emit it ready matured. So they have no testes, and the ducts are

straight and simple. There is a small part similar to this connected

with the testes in the system of quadrupeds, for part of the reflected

duct is sanguineous and part is not; the fluid is already semen when

it is received by and passes through this latter part, so that once it

has arrived there it is soon emitted in these quadrupeds also. Now

in fishes the whole passage resembles the last section of the

reflected part of the duct in man and similar animals.

Serpents copulate twining round one another, and, as said above,

have neither testes nor penis, the latter because they have no legs,

the former because of their length, but they have ducts like for on

account of their extreme length the seminal fluid would take too

long in its passage and be cooled if it were further delayed by

testes. (This happens also if the penis is large; such men are less

fertile than when it is smaller because the semen, if cold, is not

generative, and that which is carried too far is cooled.) So much for

the reason why some animals have testes and others not. Serpents

intertwine because of their inaptitude to cast themselves alongside of

one another. For they are too long to unite closely with so small a

part and have no organs of attachment, so they make use of the

suppleness of their bodies, intertwining. Wherefore also they seem

to be slower in copulation than fish, not only on account of the

length of the ducts but also of this elaborate arrangement in uniting.

It is not easy to state the facts about the uterus in female

animals, for there are many points of difference. The vivipara are not

alike in this part; women and all the vivipara with feet have the

uterus low down by the pudendum, but the cartilaginous viviparous fish

have it higher up near the hypozoma. In the ovipara, again, it is

low in fish (as in women and the viviparous quadrupeds), high in

birds and all oviparous quadrupeds. Yet even these differences are

on a principle. To begin with the ovipara, they differ in the manner

of laying their eggs, for some produce them imperfect, as fishes whose

eggs increase and are finally developed outside of them. The reason is

that they produce many young, and this is their function as it is with

plants. If then they perfected the egg in themselves they must needs

be few in number, but as it is, they have so many that each uterus

seems to be an egg, at any rate in the small fishes. For these are the

most productive, just as with the other animals and plants whose

nature is analogous to theirs, for the increase of size turns with

them to seed.

But the eggs of birds and the quadrupedal ovipara are perfect when

produced. In order that these may be preserved they must have a hard

covering (for their envelope is soft so long as they are increasing

in size), and the shell is made by heat squeezing out the moisture

for the earthy material; consequently the place must be hot in which

this is to happen. But the part about the hypozoma is hot, as is shown

by that being the part which concocts the food. If then the eggs

must be within the uterus, then the uterus must be near the hypozoma

in those creatures which produce their eggs in a perfect form.

Similarly it must be low down in those which produce them imperfect,

for it is profitable that it should be so. And it is more natural

for the uterus to be low down than high up, when Nature has no other

business in hand to hinder it; for its end is low down, and where is

the end, there is the function, and the uterus itself is naturally

where the function is.

We find differences in the vivipara also as compared with one

another. Some produce their young alive, not only externally, but also

internally, as men, horses, dogs, and all those which have hair, and

among aquatic animals, dolphins, whales, and such cetacea.

But the cartilaginous fish and the vipers produce their young

alive externally, but first produce eggs internally. The egg is

perfect, for so only can an animal be generated from an egg, and

nothing comes from an imperfect one. It is because they are of a

cold nature, not hot as some assert, that they do not lay their eggs

externally.

At least they certainly produce their eggs in a soft envelope, the

reason being that they have but little heat and so their nature does

not complete the process of drying the egg-shell. Because, then,

they are cold they produce soft-shelled eggs, and because the eggs are

soft they do not produce them externally; for that would have caused

their destruction.

The process is for the most part the same as in birds, for the egg

descends and the young is hatched from it near the vagina, where the

young is produced in those animals which are viviparous from the

beginning. Therefore in such animals the uterus is dissimilar to

that of both the vivipara and ovipara, because they participate in

both classes; for it is at once near the hypozoma and also

stretching along downwards in all the cartilaginous fishes. But the

facts about this and the other kinds of uterus must be gathered from

inspection of the drawings of dissections and from the Enquiries.

Thus, because they are oviparous, laying perfect eggs, they have the

uterus placed high, but, as being viviparous, low, participating in

both classes.

Animals that are viviparous from the beginning all have it low,

Nature here having no other business to interfere with her, and

their production having no double character. Besides this, it is

impossible for animals to be produced alive near the hypozoma, for the

foetus must needs be heavy and move, and that region in the mother

is vital and would not be able to bear the weight and the movement.

Thirdly, parturition would be difficult because of the length of the

passage to be traversed; even as it is there is difficulty with

women if they draw up the uterus in parturition by yawning or anything

of the kind, and even when empty it causes a feeling of suffocation if

moved upwards. For if a uterus is to hold a living animal it must be

stronger than in ovipara, and therefore in all the vivipara it is

fleshy, whereas when the uterus is near the hypozoma it is membranous.

And this is clear also in the case of the animals which produce

young by the mixed method, for their eggs are high up and sideways,

but the living young are produced in the lower part of the uterus.

So much for the reason why differences are found in the uterus of

various animals, and generally why it is low in some and high in

others near the hypozoma.

Why is the uterus always internal, but the testes sometimes

internal, sometimes external? The reason for the uterus always being

internal is that in this is contained the egg or foetus, which needs

guarding, shelter, and maturation by concoction, while the outer

surface of the body is easily injured and cold. The testes vary in

position because they also need shelter and a covering to preserve

them and to mature the semen; for it would be impossible for them,

if chilled and stiffened, to be drawn up and discharge it.

Therefore, whenever the testes are visible, they have a cuticular

covering known as the scrotum. If the nature of the skin is opposed to

this, being too hard to be adapted for enclosing them or for being

soft like a true 'skin', as with the scaly integument of fish and

reptiles, then the testes must needs be internal. Therefore they are

so in dolphins and all the cetacea which have them, and in the

oviparous quadrupeds among the scaly animals. The skin of birds also

is hard so that it will not conform to the size of anything and

enclose it neatly. (This is another reason with all these animals for

their testes being internal besides those previously mentioned as

arising necessarily from the details of copulation.) For the same

reason they are internal in the elephant and hedgehog, for the skin of

these, too, is not well suited to keep the protective part separate.

[The position of the uterus differs in animals viviparous within

themselves and those externally oviparous, and in the latter class

again it differs in those which have the uterus low and those which

have it near the hypozoma, as in fishes compared with birds and

oviparous quadrupeds. And it is different again in those which produce

young in both ways, being oviparous internally and viviparous

externally. For those which are viviparous both internally and

externally have the uterus placed on the abdomen, as men, cattle,

dogs, and the like, since it is expedient for the safety and growth of

the foetus that no weight should be upon the uterus.]

The passages also are different through which the solid and liquid

excreta pass out in all the vivipara. Wherefore both males and females

in this class all have a part whereby the urine is voided, and this

serves also for the issue of the semen in males, of the offspring in

females. This passage is situated above and in front of the passage of

the solid excreta. The passage is the same as that of the solid

nutriment in all those animals that have no penis, in all the ovipara,

even those of them that have a bladder, as the tortoises. For it is

for the sake of generation, not for the evacuation of the urine,

that the passages are double; but because the semen is naturally

liquid, the liquid excretion also shares the same passage. This is

clear from the fact that all animals produce semen, but all do not

void liquid excrement. Now the spermatic passages of the male must

be fixed and must not wander, and the same applies to the uterus of

the female, and this fixing must take place at either the front or the

back of the body. To take the uterus first, it is in the front of

the body in vivipara because of the foetus, but at the loin and the

back in ovipara. All animals which are internally oviparous and

externally viviparous are in an intermediate condition because they

participate in both classes, being at once oviparous and viviparous.

For the upper part of the uterus, where the eggs are produced, is

under the hypozoma by the loin and the back, but as it advances is low

at the abdomen; for it is in that part that the animal is

viviparous. In these also the passage for solid excrement and for

copulation is the same, for none of these, as has been said already,

has a separate pudendum.

The same applies to the passages in the male, whether they have

testes or no, as to the uterus of the ovipara. For in all of them, not

only in the ovipara, the ducts adhere to the back and the region of

the spine. For they must not wander but be settled, and that is the

character of the region of the back, which gives continuity and

stability. Now in those which have internal testes, the ducts are

fixed from the first, and they are fixed in like manner if the

testes are external; then they meet together towards the region of the

penis.

The like applies to the ducts in the dolphins, but they have their

testes hidden under the abdominal cavity.

We have now discussed the situation of the parts contributing to

generation, and the causes thereof.

The bloodless animals do not agree either with the sanguinea or with

each other in the fashion of the parts contributing to generation.

There are four classes still left to deal with, first the crustacea,

secondly the cephalopoda, thirdly the insects, and fourthly the

testacea. We cannot be certain about all of them, but that most of

them copulate is plain; in what manner they unite must be stated

later.

The crustacea copulate like the retromingent quadrupeds, fitting

their tails to one another, the one supine and the other prone. For

the flaps attached to the sides of the tail being long prevent them

from uniting with the belly against the back. The males have fine

spermatic ducts, the females a membranous uterus alongside the

intestine, cloven on each side, in which the egg is produced.

The cephalopoda entwine together at the mouth, pushing against one

another and enfolding their arms. This attitude is necessary,

because Nature has bent backwards the end of the intestine and brought

it round near the mouth, as has been said before in the treatise on

the parts of animals. The female has a part corresponding to the

uterus, plainly to be seen in each of these animals, for it contains

an egg which is at first indivisible to the eye but afterwards

splits up into many; each of these eggs is imperfect when deposited,

as with the oviparous fishes. In the cephalopoda (as also in the

crustacea) the same passage serves to void the excrement and leads to

the part like a uterus, for the male discharges the seminal fluid

through this passage. And it is on the lower surface of the body,

where the mantle is open and the sea-water enters the cavity. Hence

the union of the male with the female takes place at this point, for

it is necessary, if the male discharges either semen or a part of

himself or any other force, that he should unite with her at the

uterine passage. But the insertion, in the case of the poulps, of

the arm of the male into the funnel of the female, by which arm the

fishermen say the male copulates with her, is only for the sake of

attachment, and it is not an organ useful for generation, for it is

outside the passage in the male and indeed outside the body of the

male altogether.

Sometimes also cephalopoda unite by the male mounting on the back of

the female, but whether for generation or some other cause has not yet

been observed.

Some insects copulate and the offspring are produced from animals of

the same name, just as with the sanguinea; such are the locusts,

cicadae, spiders, wasps, and ants. Others unite indeed and generate;

but the result is not a creature of the same kind, but only a

scolex, and these insects do not come into being from animals but from

putrefying matter, liquid or solid; such are fleas, flies, and

cantharides. Others again are neither produced from animals nor

unite with each other; such are gnats, 'conopes', and many similar

kinds. In most of those which unite the female is larger than the

male. The males do not appear to have spermatic passages. In most

cases the male does not insert any part into the female, but the

female from below upwards into the male; this has been observed in

many cases (as also that the male mounts the female), the opposite

in few cases; but observations are not yet comprehensive enough to

enable us to make a distinction of classes. And generally it is the

rule with most of the oviparous fish and oviparous quadrupeds that the

female is larger than the because this is expedient in view of the

increase of bulk in conception by reason of the eggs. In the female

the part analogous to the uterus is cleft and extends along the

intestine, as with the other animals; in this are produced the results

of conception. This is clear in locusts and all other large insects

whose nature it is to unite; most insects are too small to be observed

in this respect.

Such is the character of the generative organs in animals which were

not spoken of before. It remains now to speak of the homogeneous parts

concerned, the seminal fluid and milk. We will take the former

first, and treat of milk afterwards.

Some animals manifestly emit semen, as all the sanguinea, but

whether the insects and cephalopoda do so is uncertain. Therefore this

is a question to be considered, whether all males do so, or not all;

and if not all, why some do and some not; and whether the female

also contributes any semen or not; and, if not semen, whether she does

not contribute anything else either, or whether she contributes

something else which is not semen. We must also inquire what those

animals which emit semen contribute by means of it to generation,

and generally what is the nature of semen, and of the so-called

catamenia in all animals which discharge this liquid.

Now it is thought that all animals are generated out of semen, and

that the semen comes from the parents. Wherefore it is part of the

same inquiry to ask whether both male and female produce it or only

one of them, and to ask whether it comes from the whole of the body or

not from the whole; for if the latter is true it is reasonable to

suppose that it does not come from both parents either. Accordingly,

since some say that it comes from the whole of the body, we must

investigate this question first.

The proofs from which it can be argued that the semen comes from

each and every part of the body may be reduced to four. First, the

intensity of the pleasure of coition; for the same state of feeling is

more pleasant if multiplied, and that which affects all the parts is

multiplied as compared with that which affects only one or a few.

Secondly, the alleged fact that mutilations are inherited, for they

argue that since the parent is deficient in this part the semen does

not come from thence, and the result is that the corresponding part is

not formed in the offspring. Thirdly, the resemblances to the parents,

for the young are born like them part for part as well as in the whole

body; if then the coming of the semen from the whole body is cause

of the resemblance of the whole, so the parts would be like because it

comes from each of the parts. Fourthly, it would seem to be reasonable

to say that as there is some first thing from which the whole

arises, so it is also with each of the parts, and therefore if semen

or seed is cause of the whole so each of the parts would have a seed

peculiar to itself. And these opinions are plausibly supported by such

evidence as that children are born with a likeness to their parents,

not in congenital but also in acquired characteristics; for before

now, when the parents have had scars, the children have been born with

a mark in the form of the scar in the same place, and there was a case

at Chalcedon where the father had a brand on his arm and the letter

was marked on the child, only confused and not clearly articulated.

That is pretty much the evidence on which some believe that the

semen comes from all the body.

On examining the question, however, the opposite appears more

likely, for it is not hard to refute the above arguments and the

view involves impossibilities. First, then, the resemblance of

children to parents is no proof that the semen comes from the whole

body, because the resemblance is found also in voice, nails, hair, and

way of moving, from which nothing comes. And men generate before

they yet have certain characters, such as a beard or grey hair.

Further, children are like their more remote ancestors from whom

nothing has come, for the resemblances recur at an interval of many

generations, as in the case of the woman in Elis who had intercourse

with the Aethiop; her daughter was not an Aethiop but the son of

that daughter was. The same thing applies also to plants, for it is

clear that if this theory were true the seed would come from all parts

of plants also; but often a plant does not possess one part, and

another part may be removed, and a third grows afterwards. Besides,

the seed does not come from the pericarp, and yet this also comes into

being with the same form as in the parent plant.

We may also ask whether the semen comes from each of the homogeneous

parts only, such as flesh and bone and sinew, or also from the

heterogeneous, such as face and hands. For if from the former only, we

object that resemblance exists rather in the heterogeneous parts, such

as face and hands and feet; if then it is not because of the semen

coming from all parts that children resemble their parents in these,

what is there to stop the homogeneous parts also from being like for

some other reason than this? If the semen comes from the heterogeneous

alone, then it does not come from all parts; but it is more fitting

that it should come from the homogeneous parts, for they are prior

to the heterogeneous which are composed of them; and as children are

born like their parents in face and hands, so they are, necessarily,

in flesh and nails. If the semen comes from both, what would be the

manner of generation? For the heteroeneous parts are composed of the

homogneous, so that to come from the former would be to come from

the latter and from their composition. To make this clearer by an

illustration, take a written name; if anything came from the whole

of it, it would be from each of the syllables, and if from these, from

the letters and their composition. So that if really flesh and bones

are composed of fire and the like elements, the semen would come

rather from the elements than anything else, for how can it come

from their composition? Yet without this composition there would be no

resemblance. If again something creates this composition later, it

would be this that would be the cause of the resemblance, not the

coming of the semen from every part of the body.

Further, if the parts of the future animal are separated in the

semen, how do they live? and if they are connected, they would form

a small animal.

And what about the generative parts? For that which comes from the

male is not similar to what comes from the female.

Again, if the semen comes from all parts of both parents alike,

the result is two animals, for the offspring will have all the parts

of both. Wherefore Empedocles seems to say what agrees pretty well

with this view (if we are to adopt it), to a certain extent at any

rate, but to be wrong if we think otherwise. What he says agrees

with it when he declares that there is a sort of tally in the male and

female, and that the whole offspring does not come from either, 'but

sundered is the fashion of limbs, some in man's...' For why does not

the female generate from herself if the semen comes from all parts

alike and she has a receptacle ready in the uterus? But, it seems,

either it does not come from all the parts, or if it does it is in the

way Empedocles says, not the same parts coming from each parent, which

is why they need intercourse with each other.

Yet this also is impossible, just as much as it is impossible for

the parts when full grown to survive and have life in them when torn

apart, as Empedocles accounts for the creation of animals; in the time

of his 'Reign of Love', says he, 'many heads sprang up without necks,'

and later on these isolated parts combined into animals. Now that this

is impossible is plain, for neither would the separate parts be able

to survive without having any soul or life in them, nor if they were

living things, so to say, could several of them combine so as to

become one animal again. Yet those who say that semen comes from the

whole of the body really have to talk in that way, and as it

happened then in the earth during the 'Reign of Love', so it happens

according to them in the body. Now it is impossible that the parts

should be united together when they come into being and should come

from different parts of the parent, meeting together in one place.

Then how can the upper and lower, right and left, front and back parts

have been 'sundered'? All these points are unintelligible. Further,

some parts are distinguished by possessing a faculty, others by

being in certain states or conditions; the heterogeneous, as tongue

and hand, by the faculty of doing something, the homogeneous by

hardness and softness and the other similar states. Blood, then,

will not be blood, nor flesh flesh, in any and every state. It is

clear, then, that that which comes from any part, as blood from

blood or flesh from flesh, will not be identical with that part. But

if it is something different from which the blood of the offspring

comes, the coming of the semen from all the parts will not be the

cause of the resemblance, as is held by the supporters of this theory.

For if blood is formed from something which is not blood, it is enough

that the semen come from one part only, for why should not all the

other parts of the offspring as well as blood be formed from one

part of the parent? Indeed, this theory seems to be the same as that

of Anaxagoras, that none of the homogeneous parts come into being,

except that these theorists assume, in the case of the generation of

animals, what he assumed of the universe.

Then, again, how will these parts that came from all the body of the

parent be increased or grow? It is true that Anaxagoras plausibly says

that particles of flesh out of the food are added to the flesh. But if

we do not say this (while saying that semen comes from all parts of

the body), how will the foetus become greater by the addition of

something else if that which is added remain unchanged? But if that

which is added can change, then why not say that the semen from the

very first is of such a kind that blood and flesh can be made out of

it, instead of saying that it itself is blood and flesh? Nor is

there any other alternative, for surely we cannot say that it is

increased later by a process of mixing, as wine when water is poured

into it. For in that case each element of the mixture would be

itself at first while still unmixed, but the fact rather is that flesh

and bone and each of the other parts is such later. And to say that

some part of the semen is sinew and bone is quite above us, as the

saying is.

Besides all this there is a difficulty if the sex is determined in

conception (as Empedocles says: 'it is shed in clean vessels; some

wax female, if they fall in with cold'). Anyhow, it is plain that

both men and women change not only from infertile to fertile, but also

from bearing female to bearing male offspring, which looks as if the

cause does not lie in the semen coming from all the parent or not, but

in the mutual proportion or disproportion of that comes from the woman

and the man, or in something of this kind. It is clear, then, if we

are to put this down as being so, that the female sex is not

determined by the semen coming from any particular part, and

consequently neither is the special sexual part so determined (if

really the same semen can become either male or female child, which

shows that the sexual part does not exist in the semen). Why, then,

should we assert this of this part any more than of others? For if

semen does not come from this part, the uterus, the same account may

be given of the others.

Again, some creatures come into being neither from parents of the

same kind nor from parents of a different kind, as flies and the

various kinds of what are called fleas; from these are produced

animals indeed, but not in this case of similar nature but a kind of

scolex. It is plain in this case that the young of a different kind

are not produced by semen coming from all parts of the parent, for

they would then resemble them, i