Abstract

In De Anima 3. 5 Aristotle discusses an active cause of human cognition. Although this cause, referred to as poietikos nous , seems not to have raised any difficult questions for the philosopher, it has been an endless source of controversy for his commentators, among whom one finds no clear consensus about the status of active mind--whether it is part of the soul of the individual knower, or a separate, external cause. ;This study, which approaches the problem of active mind in the light both of the De Anima's treatment of sensation and thinking and of the relevant texts on actuality in the Metaphysics, concludes that active mind is a separate, external cause of human knowing. Furthermore, the perfect agreement of attributes and activities between active mind and the unmoved mover of Metaphysics Lambda strongly suggests that the principle on which the argument for active mind rests is the Metaphysics' argument for a pure actuality. Accordingly, active mind, like the unmoved mover, would be a final cause, but not an efficient cause; whereas for Aristotle an efficient cause is a moved mover, active mind as "essentially an actuality" is necessarily unmoved. Most commentators, however, think that active mind is an efficient cause, first because they assume that the sensible form must be made actually intelligible by active mind before thinking can take place; second, because the text as generally interpreted requires that active mind exercise efficient causality. There is in the text of the De Anima, however, no evidence that for Aristotle thinking requires any kind of abstraction. Second, De Anima 3. 5 does not require that active mind be an efficient cause. Light, to which Aristotle compares active mind, "makes potential colors, colors in actuality" without exercising efficient causality. Furthermore, the text can be given a coherent interpretation only if one accepts this and other evidence that poiein is used there in an extended sense