The Genesis of Multiple from the Unit from the Perspective of Aquinas and Mulla Sadra

The genesis of pluralities from the unit has always been at the center of attention of philosophers since the formation of philosophy. Thomas Aquinas and Mulla Sadra have also expressed their views on it based on their philosophical and ontological foundations. How many beings originated from a simple unit preoccupied the minds of both, and they, like other philosophers, had to find a way out of this problem. The present article intends to survey the works of Thomas Aquinas and Mulla Sadra and their commentators and researchers in an analytical way to probe their views on the genesis of pluralities from the unit and as a result determine how each of them justified the genesis of pluralities from the unit. Do they pay attention to the rule of the One in this way? How did multiple being came into being? What was the first thing that came from God? The findings suggest that Thomas Acquinas, based on his ontology, denies the rule of the One and criticizes those who believe in it. But Mulla Sadra, by accepting the rule of the One, has restored it and based on his philosophical principles, has presented a new plan for it and introduced the extending existence as the first thing issued by the Supreme Being.