Aquinas on Sensible Forms and Semimaterialism

Abstract

IN THE FIRST CHAPTER OF HIS BOOK Theories of Cognition in Later Middle Ages,(1) Robert Pasnau takes position in longstanding debate concerning metaphysical status and epistemological role of sensible forms in Aquinas's theory of cognition. His main claim is that Aquinas was materialist about sensation and developed a theory of sort that modern materialist could love.(2) Pasnau's claims are interesting both from historical and from theoretical perspective. From historical point of view, they touch upon central issues of Aquinas's metaphysics, about which much work is still needed in order to understand Thomistic use of terms like material, immaterial, spiritual, and natural. From theoretical perspective, Pasnau gives reading of Aquinas's epistemology which makes it appealing for contemporary, materialistically oriented mind. This is particularly interesting, since Aquinas's epistemology has recently been reintroduced as possible contender in contemporary debates.(3) In section 1, I will outline debate about Aquinas's theory of sensation within which Pasnau takes up his position. This will not be mere reconstruction, but it will be useful in order to expound Aquinas's view as it is reconstructed in latest interpretations and also in order to highlight terms around which Pasnau's discussion is focused. In section 2, I will analyze Pasnau's arguments for semimaterialism and his objections to nonmaterialist reading of Aquinas's view. In section 3, I will try to argue that Pasnau's arguments for his semimaterialist interpretation of Aquinas are inconclusive, due to an ambiguity of term material. I will also suggest that, if my interpretation is correct, Aquinas's views cannot be acceptable to contemporary materialist. I According to Aquinas, epistemological realism is warranted by fact that, in perception, mind (or, in his words, the soul) receives form of world, that is, it is acted upon and changed by world (even if in this process it may not be completely passive) since it receives sensible forms from it. However, there are uncountable cases of reception of sensible forms, which it would be hard to consider as cases of perception: marble of statue receiving shape of model and stone receiving heat of fire are just two examples. Receiving sensible form, therefore, is not sufficient criterion for an event case of perception. Aquinas was well aware of this problem, and that is reason why he distinguished two kinds of reception of sensible forms.(4) First, thing may receive sensible form according to natural being (secundum esse naturale) or, in other terms, materially (materialiter), and then it acquires that form as one of its characteristics; for example stone which receives heat from fire becomes hot; or statue which receives shape of model, will look like model. Second, however, thing may receive form according to spiritual being (secundum esse spirituale) or immaterially (immaterialiter), and then that form will not be one of characteristics of that thing. When somebody sees green tree, she somehow receives color of tree, but her eye does not become green, nor does her brain.(5) Those things which may receive forms only materially (or naturally) have no cognitive powers (for example, stones or plants); whereas those things which can receive forms also immaterially (or spiritually), have cognitive powers (for example, animals).(6) At least two questions present themselves. Question 1: can notion of an immaterial reception of sensible forms fulfill task failed by less refined notion of reception of sensible forms, namely that of providing criterion for an event case of perception? Question 2: is an immaterial reception of sensible forms an event occurring in body (as reference to sensible forms seems to suggest) or in soul (as reference to immateriality and spirituality might seem to indicate)? …