This paper (1) criticizes Patzig's explanation of Aristotle's reason for calling his first figure syllogisms perfect syllogisms, i.e. the transitivity relation: it can only be used for Barbara, not for the other three moods. The paper offers (2) an alternative interpretation: It is only in the case of the (perfect) first figure moods that we can move from the subject term of the minor premiss, taken to be a predicate of an individual, to the predicate term of the major premiss. (...) This contention is supported (i) by Aristotle's wording of the dictum de omni et nullo and (ii) by Aristotle's use of a formula which puts the minor term in the first position when he first states Barbara and Celarent. (shrink)