This essay explores some of the central aspects of Aquinas's account of mental representation, focusing in particular on his views about the intentionality of concepts (or intelligible species). It begins by demonstrating the need for a new interpretation of his account, showing in particular that the standard interpretations all face insurmountable textual difficulties. It then develops the needed alternative and explains how it avoids the sorts of problems plaguing the standard interpretations. Finally, it draws out the implications of this interpretation (...) with the aim of correcting some persistent misunderstandings of the connection between Aquinas's views and those developed by contemporary philosophers of mind. (shrink)