The Cogent Conditional in Modern Logic

Al-Farabi and Avicenna have enumerated so many kinds of conditionals and produced a massive literature in their successors’ works. Two important kinds are the “cogent” and the “contingent,” which, in turn, are divided into more particular varieties. In this paper, I consider the “cogent conditional” and some kinds thereof. Four significant discussions here are:1. the cogent conditional’s relation to the contingent conditional and to the general condition,2. analysis of the kinds of the cogent conditional, 3. logical analysis of cogent conditional and of its kinds in Modern Logic and representing the relation between cogency and necessity, 4. the truth conditions of cogent conditional.In the recent decades, the logical analysis of the cogent conditionals and their truth-conditions has been widely discussed. But the discussions have generally been fulfilled in different ways, which are sometimes inconsistent with each other. It has even been proposed to use three-valued tableaux to analyze the cogent conditionals. In this paper, I will quote the key phrases from Ancient Logic to criticize the contemporaries’ analyses and thereby to introduce mine.