Abstract

This article firstly provides a definition for faculty and the soul and then explains the different types of faculties and the place of the faculty of internal perception. Secondly, the measure of the multiplicity of faculties that holds a very important position among philosophical issues is discussed. It is argued that the differences in acts do not indicate the existence of multiplicity in faculties, even in cases where there are two completely opposite acts. In this part, reference has been made to the different types of the faculties of internal perception which include the common sense, the imaginal faculty, the faculty of imagination, the faculty of estimation, and the faculty of memory.With regard to the common sense and the imaginal faculty,it is concluded that there is no reason for approving of the distinction between these two faculties; quite the contrary, both of them represent the same faculty which receives the perceptive forms from external senses and preserves them in itself.Concerning the faculty of estimation, after referring to Ibn Sina's reasoning for demonstrating this faculty, it becomes evident that Mulla Sadra's objection to this reasoning is not justified; however, the basis for the reasoning is false and; therefore, there is no ground for discussing the faculty of memory since it is introduced as one which preserves the perceptions of the faculty of estimation.On the basis of all contemplations in this article, it is concluded that we can only prove the existence of one faculty for internal perception for the rational soul which is the perceiver of universals. Such a faculty receives the perceptions of external senses and preserves them in itself.