In the view of Molla Sadra, the problem of incarnation is selfcontradicted.He has known human soul as an end for the natural movement of the body. Therefore, it is not reasonable for human soul to leave its own body and, instead, take another one. As Sadra says, human soul is originally material and, being in a full harmony with the body, in the process of substantial change leaves potentiality, gradually changes form and becomes immaterial. It, therefore, having attained degrees of perfection, leaves its body and enters purgatory.Such being the case, the soul can never return to potentiality and take a non-actualized body. In this way, it should be stated that incarnation cannot be agreed with while considering Sadra's view on the actualization of the soul in the process of substantial change.