It is beyond doubt that during the last three and half centuries, all intellectual schools of thought in Iran have been influenced by Mullā Sadrā’s philosophy. He is considered to be among the Prime Theoretician of Islamic intellectual sciences. One of Sadrā’s innovations in philosophy is the doctrine of the trans – substantial motion. The concept of motion lies at the heart of Sadrā’s philosophy. The Aristotelian natural motion is substituted by the ontological and trans – substantial motion. In fact, He turns the classical concept of substance into a structure of events, and a process of change. This motion is emanating from the perpetual source of Divine Grace.
Based on the trans – substantial motion, Sadrā proves the existence of God and the resurrection. Moreover, he solves the problem of origination and eternity, the relation of the changing to the permanent, and the problem of the soul and its union with the body. Finally, Mullā Sadrā, by considers the issue of the union of the intellect and the intelligible, attempts to solve the most difficult philosophical problems.
At first, this article presents a summarized background of philosophy in Iran, and explains the theory of the trans – substantial motion. Then, we assert Sadrā’s innovations based on this theory.