Book 7
9
Surely not. The essence is an individual type; but when a subject has something distinct from it predicated of it, it is not an individual type. E.g., white man is not an individual type; that is, assuming that individuality belongs only to substances. Hence essence belongs to all things the account of which is a definition.
10
We have a definition, not if the name and the account signify the same (for then all accounts would be definitions; because any account can have a name, so that even the Iliad will be a definition), but if the account is of something primary. Such are all statements which do not involve the predication of one thing of another.
11
Hence essence will belong to nothing except species of a genus, but to these only; for in these the predicate is not considered to be related to the subject by participation or affection, nor as an accident. But of everything else as well, if it has a name, there will be a formula of what it means—that X belongs to Y; or instead of a simple formula one more exact—but no definition, nor essence.
12
Or perhaps definition, like the what, has more than one sense. For the what in one sense means the substance and the individual, and in another each one of the categories: quantity, quality, etc.
13
Just as is applies to everything, although not in the same way, but primarily to one thing and secondarily to others; so what it is applies in an unqualified sense to substance, and to other things in a qualified sense. For we might ask also what quality is, so that quality also is a what it is; not however without qualification, but just as in the case of not-being some say by a verbal quibble that not-being is—not in an unqualified sense, but is not-being—so too with quality.
