We have said that example is a kind of
induction and with what kind of material it deals by way of induction. It is
neither the relation of part to whole, nor of whole to part, nor of one whole to
another whole, but of part to part, of like to like, when both come under the
same genus, but one of them is better known than the other. For example, to
prove that Dionysius is aiming at a tyranny, because he asks for a bodyguard,
one might say that Pisistratus before him and Theagenes of Megara
did the same, and when they obtained
what they asked for made themselves tyrants. All the other tyrants known may
serve as an example of Dionysius, whose reason, however, for asking for a
bodyguard we do not yet know. All these examples are contained under the same
universal proposition, that one who is aiming at a tyranny asks for a bodyguard.
We have now stated the materials of proofs which are thought to be demonstrative.