Michael Wolff über Beweise für vollkommene Syllogismen bei Aristoteles

Abstract

This paper is a reply to Michael Wolff’s refusal of my critique of his „Vollkommene Syllogismen und reine Vernunftschlusse bei Aristoteles und Kant“, as far as Aristotle concerned. Wolff claims (1) that a perfect Aristotelian syllogism is not characterized by its evidence and (2) that, therefore, it is in need of a proof. Against Wolff’s first claim I point out that to talk of „making the necessity apparent/evident“ in Aristotle’s definition of the perfect syllogism at An. Pr. I 1, 24b22f. speaks in favour of the view that a perfect syllogism is a syllogism in which the validity of the inference is evident. I further argue that in order to make the validity evident, Aristotle uses the wording of a term „to be contained in another as in a whole“ atAn.Pr. I 4, 25b32–35with the effect that there is a logically valid passage from the predicate term of theminor to the subject term of themajor premise. As toWolff’s second claim I argue, first, that nowhere in the An. Pr. does Aristotle give a proof for a perfect syllogism, and, second, that Wolff’s attempts to make his claim plausible rely either on a misreading of the Aristotelian texts or else are question-begging. In particular, I argue that the dictum de omni/de nullo, respectively, are not meant to function as proofrules but rather as translation-rules: they have a role in licensing the switch from the ‚terminological‘ formulations Aristotle mostly uses for his syllogisms (e.g.‚ A belongs to every B’) to the ‚being contained as in a whole‘-wording.