Abstract

1 Trans-substantial motion is one of the most important philosophical discussions in the history of the Islamic culture and philosophy, which has become known with the name of Sadr al- Muta'allihin Shirazi. One must admit that the greatness of this theory and its deep, and wide-spread influence on the philosophical meditation of Muslims is no less than that of the theory of General Relativity of Einstein in physics and the Process philosophy of head in the domain of philosophy.Before the rising of the theory of substantial motion, scholars generally agreed that movement and transformation in the substance of an object were illogical and impossible phenomena. The words of the Islamic gnostics and theologians who believed in continuing creation can rather be viewed as compatible with this theory. But the one who has explicitly proposed this problem, and has bravely insisted on proving it is the most prominent philosopher of the Islamic world, Sadra al-Muta'allihin Shirazi. He considers motion nothing but constant renovation and renewal of the world in each moment. He concludes, within his philosophical system, that not only accidents but also the very substance of the world is constantly in motion and renovation.This principle constitutes the basis of Mulla Sadra's worldview. It is under the auspices of this principle that he repressents a new philosophical explanation of the exact physical and metaphysical problems including the temporal contingency of the world, the relationship between constant and variable, the creation of the world, the continuing creation, the relationship between soul and body, the resurrection of the body, and many ather problems about resurrection. He also analyzes and explains the story of motion and transformation, and its spread and generality, together with its philosophical results and consequences in a deep and vast meaning, and from a very strong and effective viewpoint.This principle, as a comprehensive and unifying theory, which indicates the source and resurrection entirely, must be counted as one of the fundamental and distinguished properties of Sadr al-Muta'allihin's theorizing. In this work we intend to explain this principle, introduce its consequences, and characterize the role played by each of them in opening a new outlook in the domain of philosophy. We will, as well, clarify the history of evolution of the substantial motion; and analyze the new thought proposed by Sadr al- Muta'allihin which has caused a transformation in it.