Per Se, Inseparability, Containment and Implication. Bridging the Gap between Avicenna’s Theory of Demonstration and Logic of the Predicables

Abstract

The notion of per se (kath’hauto) is a signature component of Aristotle’s theory of science. This paper has two aims: (i) to examine for the first time Avicenna’s (d. 1037) account of per se (ḏātī) in the context of his theory of demonstration, especially in the Kitāb al-Burhān, and more generally in what I shall call the Posterior Analytics complex, i.e., a larger set of relevant texts from Avicenna’s logical works that deal with An. Post., and (ii) to connect it with his theory of predicables as formulated in the Kitāb al-Madḫal, and more generally in what I shall call, by analogy, the Isagoge complex.In the Posterior Analytics complex, Avicenna reasserts the role of per se predication and articulates an innovative and systematic interpretation (showing a debt towards Fārābī and the Greek commentary tradition) of the notions of per se 1 and per se 2 originally developed by Aristotle in An. Post. A4 around the idea of a term being taken in the definition of another term. In the Isagoge complex, Avicenna understands per se 1 and 2 in terms of two types of entailment of different strength—containment (taḍammun) and implication (iltizām)—, which are in turn associated with the technical notions of inseparability in conception (taṣawwur) and in imagination (tawahhum). As a result, the distinction between per se 1 and 2 in Avicenna turns out to be philosophically grounded in a larger theoretical framework than it is in Aristotle.In addition to its intrinsic interest, Avicenna’s solution also counts as an interpretive effort that aims to solve some traditional exegetical problems in Aristotle, e.g., the question whether the class of per se 2 predicates from An. Post. A4 and that of per se accidents coincide, an issue that has vexed commentators since antiquity.