Substantial Departure of Human Soul and Stability of Knowledge

Undoubtedly the theory substantial departure as a great innovation has been originally established by Molla Sadra and fundamentally affected Islamic philosophy. Another important theory explained by Sadra after Avicenna's opposition is the unity of the knowing and the known. Though the theories are deeply interrelated, they have caused various problems that solving them would prepare the ground to solve many other philosophical problems. As is claimed in the second theory, the known by essence is the same as the knowing with regard to existence. However, on the basis of the first theory human soul, as the knowing, while in gradual departure by arriving at new knowledge at every instance, would cause the known to change. Here the question arises that how we can argue for unchangeable knowledge? This paper has studied the question.