MIND AND SOUL property: sensibile in actu) The importance of the truism is precisely to rule out the naive representationalism that is tempting in this area In addition to the Wve outer senses, Aquinas believed that there were inner senses, and took over a list of them from Avicenna: the general sense, the memory, the imagination, and a fourth faculty, which in animals is called the vis aestimativa and in humans the vis cogitativa The vis aestimativa seems to correspond to our notion of ‘instinct’: animals’ inborn appreciation of what is useful or dangerous, expressed in such activities as nestbuilding or Xeeing from predators Aquinas does not succeed in making clear what he regards as the equivalent human capacity (ST 1a 78 4) Many philosophers besides Aquinas have classiWed memory and imagination as inner senses They have regarded these faculties as senses because they saw their function as the production of imagery; they regarded them as inner because their activity, unlike that of the outer senses, was not controlled by external stimuli Aquinas, indeed, thought that the inner senses, like the outer ones, had organs—organs that were located in diVerent parts of the brain It seems to be a mistake to regard the imagination as an inner sense It has no organ in the sense in which sight has an organ: there is no part of the body which can be voluntarily moved so that we can imagine better, in the way that the eyes can be voluntarily moved so that we can see better Moreover, it is not possible to be mistaken about what one imagines in the way that one can be mistaken about what one sees: others cannot check up on what I say I imagine as they can check up on what I claim to see These are crucial diVerences between imagination and genuine senses Fortunately much of what Aquinas has to say about the role of the imagination and its relation to the intellect is unaVected by this excessive assimilation to the Wve senses Calling it a sense—and therefore, for Aquinas, a faculty wholly within the realm of the material—has the great advantage of distinguishing it from the intellect Many philosophers have conceived the mind as an immaterial and private world, the locus of our secret thoughts, the auditorium of our interior monologues This is a profound mistake Of course it is undeniable that human beings can keep their thoughts secret and talk to themselves without making any noise and call images before their mind’s eye But this ability, for Aquinas, is not the mind: it is not the intellect but the imagination 235