A History of Conversion and Contraposition in Islamic Logic

“Aks” is a name applicable both on Conversion and Contraposition. The purpose of this article is to draw the historical perspective of the two logical rules, aiming to achieve a small part of big puzzle of the ‘History of Islamic Logic’. Limiting itself to the history and geography of Islamic World, the article traces the line of development, immediately after Aristotle, in Farabi and Ibn Sina; then follows it in Baghdadi, Suhrawardi, Fakhr al-Din Razi, Kashi, Bamiyani, Khunaji, Urmawi, Abhari, Tusi, Katibi, Hilli, and finally, Qutb al-Din Razi. After Qutb, Islamic logic catches stagnation and even declines. Therefore, we cannot expect any innovation from the later logicians, not only in conversion and contraposition, but also in other logical topics.