The Categories by Aristotle (good ebook reader TXT) 📖

Part 5

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