Doctoral Thesis / Dissertation from the year 2014 in the subject Philosophy - Philosophy of the Ancient World, University of Sao Paulo; Department of philosophy, language: Portugues, abstract: Our major aim here was to research the philosophical relations of logic as tool according to the ancient Aristotelians untill Alexander of Aphrodisias. After our critical assessments of recent interpretations, it is even clearer that Aristotle had not any idea of logic as tool. Since Aristotle could not have argued for such doctrine, our research focused on one of the most significative contexts in which it appears, namely, in a debate with the Stoics; contrary to the ones who said logic is no part, but an instrument of philosophy, the Stoics themselves sustained that logic is part of philosophy and we assessed their arguments for this. It is true that these two theses are not throughout contradictory between them, in so far as, in the period between Aristotle and Alexander, there are signals of a compatibilist thesis, i.e. that the logic had been regarded as part and tool. May as it be, the Aristotelians criticized the arguments for logic as part, which we analyzed, as well as some positive arguments of the Aristotelian school; accordingly, the meaning of some discipline as an instrument (in Greek organon) was clear. That means: a discipline-organon implied relations with the concept of architectonicity; for, according to texts of Aristotle, objects and even technicians of some disciplines could be used as tools by other more architectonic disciplines; that is why later Peripateticians named the subordinate disciplines themselves tools; the concept of instrumental discipline implies that it helps to the finality of its superior. That in mind, we could see the specific case of logic which, as at least Alexader of Aphrodisias clearly regarded, helps to the contemplation, the utmost finality of man.