al-Taftazani on Predication and the Unity of Proposition

Abstract

Affirmative propositions in classical logic-typically expressed as this is that-seem, at first glance, to run afoul of the principle of identity, since they appear to state that something is other than itself. The standard way of addressing this difficulty was to posit a union (ittihad) between subject and predicate, often explained in terms of their external existence. Yet this account proves inadequate for propositions concerning non-existent or impossible entities, such as The Partner of God is impossible or The triangle is a shape. This paper examines Taftazani's reformulation of the union point through his thesis of misdaq, according to which subject and predicate must coincide in referent. By analyzing his discussions in Sharh al-Maqasid and Sharh al-Shamsiyya, the study shows how this thesis draws together earlier solutions, relates to the principle of existential import (tafri), and makes possible affirmative predication even of impossible objects.