Study Notes. How are we to reconcile the claim that no universal is substance and the claim that an essence is a substance? For surely essences are universals?
(a) If forms are to be understood in the usual way, i.e. as universals, then in order to maintain their claim to be substances we must apparently say that Z13 does not really mean to argue that no universal is a substance. But this interpretation conflicts with what our text actually says, such as “nothing predicated universally is a substance…”
(b) An Alternative version of this line of interpretation holds that Aristotle is attaching an unexpected sense to the word “universal”. The idea is that he still conceives of essences as in our sense universal, but they are no longer to be counted as universal in his sense, for in his sense, “universal” now means “more universal than is the indivisible species-form”. One objection can be noted: This interpretation certainly posits a change in Aristotle’s use of the word “universal”. Yet Aristotle does not appear to intend any such change.
2. Bostock’s conjecture: there was an earlier version of Z13 in which the species-form was counted as a substance, and a later version in which it was not. The crucial part of the conjecture is that (2) part of the earlier version and was not intended to be part of the later version at all, whereas the later version contained (1), (3), (4), (5).
(a) Earlier version: so long as the universal species-form is still allowed as a substance, the claim that anything more universal than this is not a substance fits well enough with Aristotle’s doctrine elsewhere.
(b) Whether this version is taken as implying that only particular men, horses, trees, and so on, could be substances, or whether it is taken as implying that only their particular forms could be substances, in either case it is clearly not consistent with the main thrust of Z4-11. It is also contradicted by the opening o fZ15, which implies that both universal forms and concrete particulars are substances.
But why should Aristotle have wished to destroy his earlier discussion in this way? Had he come to believe in particular forms? Could it…?
