Abstract

In this paper, by a short review of the meaning of the trans-substantial motion in Mulla Sadra's ontological philosophy, and by paying attention to the elements that are used in explaining the trans-substantial motion, particularly the world soul, the writer concludes that this motion is not merely meaningful in the arc of ascent and based on the Aristotelian definition of motion, that is, the specific Aristotelian concepts of "potency and act". Rather, it has such a vast meaning that one can refer to the trans-substantial motion, i.e. ontological motion, in the arc of descent, too. Basically, in a philosophy which also deals with the arc of descent, one cannot justify motion only in the arc of ascent, particularly when considering that motion originates in life and is an essential feature of existence. In the rest of the paper, the writer briefly reviews Mulla Sadra's philosophical psychology in the two arcs of being by focusing on the relationship between the human existence and motion in these two arcs. Of course, this focus is only to remind us of Mulla Sadra's belief in the parallelism of the levels and worlds of being in the arcs of ascent and descent and leads us in the course of discussion to the intended purpose.