Book 7

Section 6

We must inquire whether the essence is the same as the particular thing, or different. This is useful for our inquiry about substance; because a particular thing is considered to be nothing other than its own substance, and the essence is called the substance of the thing.

In accidental predications, indeed, the thing itself would seem to be different from its essence; e.g., white man is different from essence of white man. If it were the same, essence of man and essence of white man would be the same. For man and white man are the same, they say, and therefore essence of white man is the same as essence of man.

But perhaps it is not necessarily true that the essence of accidental combinations is the same as that of the simple terms; because the extremes of the syllogism are not identical with the middle term in the same way. Perhaps it might be thought to follow that the accidental extremes are identical; e.g. essence of white and essence of cultured; but this is not admitted.

But in per se expressions, is the thing necessarily the same as its essence, e.g., if there are substances which have no other substances or entities prior to them, such as some hold the Ideas to be?

For if the Ideal Good is to be different from the essence of good, and the Ideal Animal and Being from the essence of animal and being, there will be other substances and entities and Ideas besides the ones which they describe; and prior to them, if essence is substance. And if they are separate from each other, there will be no knowledge of the Ideas, and the essences will not exist

(by being separate I mean if neither the essence of good is present in the Ideal Good, nor being good in the essence of good); for it is when we know the essence of it that we have knowledge of a thing. And it is the same with other essences as with the essence of good; so that if the essence of good is not good, neither will the essence of being be, nor the essence of one be one.

Either all essences exist alike, or none of them; and so if not even the essence of being is, neither will any other essence exist. Again that to which essentially good does not apply cannot be good. Hence the good must be one with the essence of good, the beautiful with the essence of beauty, and so with all terms which are not dependent upon something else, but self-subsistent and primary.

For it is enough if this is so, even if they are not Forms; or perhaps rather even if they are. (At the same time it is clear also that if the Ideas are such as some hold, the substrate will not be substance; for the Ideas must be substances, but not involving a substrate, because if they did involve one they would exist in virtue of its participation in them.)

That each individual thing is one and the same with its essence, and not merely accidentally so, is apparent, not only from the foregoing considerations, but because to have knowledge of the individual is to have knowledge of its essence; so that by setting out examples it is evident that both must be identical.

But as for the accidental term, e.g. cultured or white, since it has two meanings, it is not true to say that the term itself is the same as its essence; for both the accidental term and that of which it is an accident are white, so that in one sense the essence and the term itself are the same, and in another they are not, because the essence is not the same as the man or the white man, but it is the same as the affection.

The absurdity 〈of separating a thing from its essence〉 will be apparent also if one supplies a name for each essence; for then there will be another essence besides the original one, e.g. the essence of horse will have a further essence. Yet why should not some things be identified with their essence from the outset, if essence is substance? Indeed not only are the thing and its essence one, but their formula is the same, as is clear from what we have just stated; for it is not by accident that the essence of one, and the one, are one.

Moreover, if they are different, there will be an infinite series; for the essence of one and the one will both exist; so that in that case too the same principle will apply. Clearly, then, in the case of primary and self-subsistent terms, the individual thing and its essence are one and the same.

It is obvious that the sophistical objections to this thesis are met in the same way as the question whether Socrates is the same as the essence of Socrates; for there is no difference either in the grounds for asking the question or in the means of meeting it successfully. We have now explained in what sense the essence is, and in what sense it is not, the same as the individual thing.