Throughout most of his famous treatise De Anima Aristotle seems content to speak of the intellect (νο( ilde{v} )ς) as though it were a single, unified faculty. However, in chapter 5 of book III, and in this place alone, he introduces a distinction between that intellect which "makes all things" and that which "becomes all things."¹ The former intellect, while not expressly so termed by Aristotle, has appropriately enough come to be known as the "agent intellect" (νο( ilde{v} )ς ποιητικός)²; the latter intellect is denominated by Aristotle as "potential" (δυνáμει). Aristotle speaks also, in the closing line of this same chapter, of a "passive intellect" (νο( ilde{v} )ς παθητικός), a designation which he never repeats. The very brevity of Aristotle's discussion (this chapter is one of the shortest in the entire De Anima) and the fact that the distinction he here draws seems nowhere to be developed in his other works, has left his commentators with a serious problem of interpretation.