The Sensus Communis. The First of the Internal Sense Faculties
The next block in building Aquinas’s theory of perception is an analytic account of the internal senses. Aquinas again adopts a rigorous faculty psychology. The internal senses have a greater and a more detailed contribution to make in human perception than is suggested in the writings of many classical and contemporary epistemologists from Locke and Berkeley to Russell, Moore, and Ayer. In opposition to much modern and contemporary accounts of inner sense by the internal senses, Aquinas does not refer exclusively to acts of introspective awareness. On the contrary, he posits a unique set of inner sense faculties, each of which has a specific role to play in a perceiver’s awareness of the world. The internal sense faculties exhibit more cognitive capabilities than the standard use of ‘itches’ and ‘tickles’ common in the writings of mid-century analytic philosophers. Yet an analysis of this section of his philosophy of mind is not always clear. Even a sympathetic critic like Kenny writes: ‘Aquinas’s treatment of the inner senses is not one of the more satisfactory parts of his philosophy of mind.’1 Stump too gives scant attention to the internal senses: ‘in what follows, I will consider only phantasia and imagination among the internal senses.’1  
-  Anthony Kenny, Aquinas on Mind (New York: Routledge, 1993), 39.
-  Eleonore Stump, Aquinas (London: Routledge, 2003), 248. Stump’s account of mental events inAquinas is, on the whole, extraordinarily good. The distinction she makes between phantasia and imagination needs to be discussed. It should be noted that Stump does not consider the vis cogitativa, which is animportant faculty of the internal sensorium. She appears to consider the vis aestimativa as coextensive withthe vis cogitativa in Aquinas; however, to equate both faculties is a textual and a structural categorymistake.