Historical Evolution of the Quiddity of the Conventional Propositions among Muslim Logicians

This study aims to examine the historical development of conventional propositions among Muslim logicians. The findings shows that Farabi and Ibn Sina believe that the concept of “genus” of conventional propositions has the idea of surmise and they refer to the ultimate function of conventional propositions in practical field. The next logicians have chosen the proposition as the concept of genus of conventional propositions that may show the change of their position about the concept of proposition and its scope. Logicians before the seventh century have proposed definitions similar to the definition of “Nejat” and “Esharat” of Ibn Sina. Logicians of the seventh century have used from the word of “yahkom” that such an approach is the result of the issues of necessity of judgment, criteria and factors of conventional propositions in the scope of innateness. In the meantime, the views of Tusi and Hilli due to the new situation in the types of conventional propositions and understand its heteronym have a unique feature. The most important approaches can be seen in the definitions of the commentators of “Shamsiyya”. They have used the most important issues in the definition of conventional propositions from their perspective. Qutb Razi refers to the first reaction of people to these views. Taftazani pay attentions to the the different value of certainties and conventional propositions and Sialkoti expresses his idea in a new style by studying the commentators of “Shamsiyya”.