I examine Aristotle’s definition of scientific knowledge in Posterior Analytics 71b 9-12 and try to understand how it relates to the sophistical way of knowing and to "kata sumbebekos knowledge". I claim that scientific knowledge of p requires knowing p by its appropriate cause, and that this appropriate cause is a universal (katholou) in the restricted sense Aristotle proposes in 73b 26-27 ff., i.e., an attribute coextensive with the subject (an extensional feature) and predicated of the subject in itself (...) (an intensional feature). Kata sumbebekos knowledge, on the other hand, can occur even when the predicate of a conclusion is coextensive with its subject and is proved by a convertible meson which is not the most appropriate from an explanatory standpoint. (shrink)

I discuss an important feature of the notion of cause in Post. An. 1. 13, 78b13–28, which has been either neglected or misunderstood. Some have treated it as if Aristotle were introducing a false principle about explanation; others have understood the point in terms of coextensiveness of cause and effect. However, none offers a full exegesis of Aristotle's tangled argument or accounts for all of the text's peculiarities. My aim is to disentangle Aristotle's steps to show that he is arguing (...) in favour of a logical requirement for a middle term's being the appropriate cause of its explanandum. Coextensiveness between the middle term and the attribute it explains is advanced as a sine qua non condition of a middle term's being an appropriate or primary cause. This condition is not restricted either to negative causes or to middle terms in second‐figure syllogisms, but ranges over all primary causes qua primary. (shrink)