Aristotle's theory of perception: physiology and psychology

Abstract

The topic of my dissertation is Aristotle's doctrine that the faculty of perception receives the forms of sensible things without the matter. Whether his doctrine is an account of a physiological process or an account of the soul's activity in perception has been a matter of dispute among contemporary scholars. These two interpretations I call the physiological and the cognitive. In an attempt to settle the dispute, I present Aristotle's physiology of perception as it can be gleaned from the de Anima and the Parva Naturalia and his theory of the cognitive faculties of the soul. I advance an interpretation according to which receiving sensible forms without the matter is an activity of the soul that takes place when the appropriate physical changes occur in the heart, which is the primary sense organ and the body part most closely associated with the soul. Part of Aristotle's physiology of perception includes alterations in the outer sense organs in which some receptive material becomes like the sensible object with respect to a sensible quality. On the physiological interpretation, this becoming like is identical with receiving sensible form without the matter. I claim that it is only the first stage, which in itself is neither the reception of sensible form nor the actualization of the perceptual faculty. These occur when the primary sense organ is stimulated. This stimulation is what Aristotle compares to the imprinting of a signet ring on sealing wax. That the sign signifies the sender is analogous to the perceiver having cognition of a sensible object. Just as the showing of the sign depends on the wax being altered on its surface, so too the cognition depends on some alteration in the primary sense organ. In this study, I expand and explain Aristotle's dictum that an act of perception is a change in the soul through the body.