Avicennian Logic, Innovations and Novelties

Aristotelian logic (predicative logic) through direct translation and by virtue of Aristotle’s works, and Stoic – Megarian logic (conditional logic) through indirect translation and by virtue of some Latin texts of Galen, Alexander of Aphrodisias and Boethius belonging to the early centuries of Christion era was introduced into Islamic world. After two centuries of attempt to translate, exposition, ulterance and understanding the Greek logical heritage, with Ibn Sina “the period of innovation and originality began. Ibn Sina’s logical innovations and logics of innovation, in particular the two theories of “conjunctive syllogism” and “temporal modalities” that by attempts in two hundred later until khaje Nasir al _ Din tusi came to such a perfection and solid foundation that this period of logical investigations can be called as “Avicennian logic” or “logic of Ibn Sina” and one shouldemphasize on its importance and independence in comparison to Aristotelian and Stoic-Megarian schools. In the present article the author besides giving a brief treatment of the two above – mentioned theories, presents his reasons for proving of the idea of “Avicennian logic”.