Folia Theologica 12. (2001)
Tibor Rászlai: Aquinas ont the Infallibilty of the Intellect
THE INFALLIBILITY OF THE INTELLECT 133 I'm taking the 'certain sort of' as a reference to the as yet not fully known essence. The reference would seem to be in virtue of the instances of the properties that are taken as part of the essence; the phrase in question refers to their underlying cause. As he says in an analogus case, when speaking of using accidentia propria in place of unknown essential properties, the accidentia propria are used in the definition as "effects of the substantial forms, and as making these forms known /manifest eas/".32 33 That is, they are used to identify demonstrably the underlying essence that is to be discovered. As the reader will recognize, I am attributing to Aquinas an externalism for concepts, the view, current in philosophical literature, that the individuation of at least some of our concepts depends not only on what is "in our mind" (as we have access to this through introspection), but also depends on the environment.34 Returning now to the objection raised above, we can see that our initial grasp of quiddities may fall far short of full understanding - one may only apprehend part of the essence and remain ignorant of many or most essential properties. When this occurs, one's understanding may be expressed in a sort of nominal definition in which proper accidents stand in place of essential differences, as signifying the essence that is their cause. When we have such an imperfect grasp, we must employ fallible reasoning to come to a full grasp pf the essence. In spite of such imperfect apprehensions, however, Thomas may still claim that our ideas, our rationes, do, in fact, correspond to the essences causally responsible for the phantasmata considered by the intellect, and, so, do correspond to the essences of things in the world. This amounts to the claim that the natural, essential kind classifications that the intellect spontaneously forms do, in fact, correspond to the real essences of what one perceives, and thus we need not expect a reworking of our conceptual structure in the light of further inquiry. Our intellects in their first operation do "cut the world at its joints", even though we may have much to learn about the essences so classified. 32 Ibid. 33 ST I., q. 29., a. 1. ad 3. 34 A good example of a recent exposition of this sort of externalism be found in Colin McGinn? “The Structure of Content.“ In: Thought and Object. New York, 1982.
