The Nature of Estimation and its Role in Errors of Mind in Mulla Sdra's View

On inner sense there are many problems in traditional psychology which are mainly ontological such as corporeality or incorporeality of inner senses, their number and the proof for the existence of each of them.In the present article one of the inner senses namely "estimation" is to be epistemologically studied. Necessity of such study is due to the crucial role of this faculty in the error of mind. Islamic philosophers including Ibn Sina, Suhrawardi and Mulla Sadra held it to be the source of faults of mind and gateway of Satan to deceive human for avoidance of which logic has been designed as a science that can prevent reason and mind from the interpositions of imagination and estimation. In spite of its importance and acknowledging its critical role in misguiding mind, the estimation faculty has not so far received sufficient attention. In view of the fact that epistemological problems are interconnected with ontological discussions this article is to examine first the nature of estimation from Sadra's viewpoint and then deals the way and reason why it leads mind to error.