Active power and causal flow in Aristotle's theory of vision.

Aristotle's theory of vision has been characterized as naive, incommensurate with his theory of audition, and of historical interest only. This view is based on an analysis which fails to acknowledge the role of the concepts acting upon and active power in the theory. The meaning of these terms and the role Aristotle assigned them in vision and in sensation generally is demonstrated. It is argued that with the inclusion of these concepts (1) the theory of vision is sufficiently sophisticated and modern to be more than comparable with more recent perceptual theorizing, and (2) theoverall integrity of Aristotle's sensory philosophy is preserved. It is further argued that given the cohesiveness and comprehensiveness of Aristotle's psychological works, more attention should be given them by modern psychologists.