It is the opening statement of the Post Analytics.

Aristotle in his logical analysis of Induction, Prior. Analytics II. 25, defines it to be “the proving the inherence of the major term in the middle (i.e. proving the truth of the major premiss in fig. 1) through the minor term.” He presupposes a Syllogism in the first Figure with an universal affirmative conclusion, which reasons, of course, from an universal, which universal is to be taken as proved by Induction. His doctrine turns upon a canon which he there quotes. “If of one and the same term two others be predicated, one of which is coextensive with that one and the same, the other may be predicated of that which is thus coextensive.” The fact of this coextensiveness must be ascertained by [Greek: nous], in other words, by the Inductive Faculty. We will take Aldrich’s instance. All Magnets attract iron A B C are Magnets A B C attract iron. Presupposed Syllogism reasoning from an universal. A B C attract iron (Matter of observation and experiment) All Magnets are A B C (Assumed by [Greek: nous], i.e. the Inductive faculty) All Magnets attract iron (Major premiss of the last Syllogism proved by taking the minor term of that for the middle term of this.) Or, according to the canon quoted above: A B C are Magnets. A B C attract iron.