ABSTRACT
Aristotle was the creator of logic in the West – so the people are constantly re minded. This trivial historical truth makes it all the more difficult to accommodate a couple of facts about the way he deals with logic. With striking consistency throughout the corpus, Aristotle says that all sciences fall under three types only, being either theoretical, practical, or productive. The internal order that the people find today in the Organon seems to have been fixed by the Alexandrian authors, where they find it for the first time explicitly assumed. To conclude, a few words on the authenticity and title of the treatises that compose this Organon, as well as on their relative and absolute chronology. The substitution of something accidental for one of the relata is, on Ferreira’s view, the common mistake at the origin of all examples of the fallacy of accident.
