Suhrawardi's Logical Innovations and the Solution to the Problems of Modern Logic in Analyzing Quantified Propositions

According to the analysis of quantified propositions in modern logic, many of the rules pertaining to propositions in classic logic will be considered as invalid. Many of these rules are related to deducing a particular proposition from a universal proposition or universal propositions. They include direct argumentations such as subaltern, simple conversion, conversion by contradiction (contraposition), square of oppositions and [indirect argumentations] such as some modes of the third and fourth forms of conjunctive syllogism. The present article tries to study one of Suhrawardi’s logical innovations, that is, the reduction of a particular proposition to a universal one through supposition, which serves as a solution to the aforementioned problem. It seems that his innovative solution solves all the mentioned problems except the problem of contrast. The question of the invalidity of contradiction, however, emerges as a new problem.