Kitap 1
8
If the form of the Ideas and of the things which participate in them is the same, they will have something in common (for why should Duality mean one and the same thing in the case of perishable twosi.e. pairs of sensible objects. and the twos which are many but eternal,i.e. mathematical 2s. and not in the case of the Idea of Duality and a particular two?); but if the form is not the same, they will simply be homonyms; just as though one were to call both Callias and a piece of wood man, without remarking any property common to them.The argument of 7-8 is: Ideas are substances. The common name which an idea shares with its particulars must mean the same of both; otherwise participation is merely homonymy. But as applied to Ideas it denotes substance; therefore particulars must be substances.
9
Above all we might examine the question what on earth the Forms contribute to sensible things, whether eternal or subject to generation and decay; for they are not the cause of any motion or change in them.