II. To the Principal Argument

41. And from what has been said the answer to the principal argument [n.2] is plain, that the Philosopher is rejecting the invention that he imputes to Plato, namely because ‘this man’ existing per se - which is posited to be the Idea - cannot be per se universal to every man, because ‘every substance existing per se is proper to that in which it is’, that is: either it is of itself proper or it is made proper by something contracting it and, once this something contracting it is posited, it cannot be in anything else, even though being in something else is not repugnant to it of itself - and this gloss is certainly true when speaking of substance as it is taken for nature; and then it follows that the Idea will not be the substance of Socrates because it is not even the nature of Socrates - for the Idea is neither proper of itself nor made so proper to Socrates that it exists only in him, but it exists also, according to Plato, in someone else. But if substance is taken for first substance, then it is true that any substance is of itself proper to that to which it belongs, and then it much more follows that the Idea - which is posited as a ‘substance existing per se’ - cannot be in that way the substance of Socrates or of Plato; but the first member [sc. substance as taken for nature] suffices for the conclusion.