Nicholas E. Lombardo, O.P. does a great job of showing how, for Thomas, human psychology is rooted in metaphysics. To see this one need only to note that in ST I 5 the Angelic Doctor establishes that being is convertible with the good (everything that exists is good, and vice-versa), and that the good is that which is desirable, or “appetible.”
Hence all existing things, and not just animals (rational or otherwise) are characterized by desire or appetite: they all strive toward their perfection / fulfilment / telos.
As Lombardo rightly concludes: “Consequently, for Thomas, all being is ecstatic.” (Lombardo, _Logic of Desire_, 26).
Prior to reading this book, had someone asked me, “Why, for Thomas, is all being ecstatic?” I probably would not have known what to say. In fact, last semester I read deeply in John Wippel’s The Metaphysical Thought of Thomas Aquinas, and while I do recall his emphasis that being is “pure act,” I don’t recall him connecting being’s activity or ecstasis specifically to desire or appetite.
From the perspective of theological anthropology, what should one make of contemporary “brain science?” That is, when you are at a conference and the scientific expert is locating various human activities (fear, abstract thinking, anger, etc.) in various specific parts of the brain, is this coherent from a theological point of view?
It is tempting for me (as a traditionalist Christian) to say, “No, because abstract thinking, for example, is not spatially located.” (You see, I am not a material reductionist; I believe in an immaterial soul, at least in human beings.)
But wait. This is where Thomas comes in. Thomas would distinguish between, say, fear on the one hand, and “universal reason” on the other. For Thomas, the former _is_ spatially localizable, since nonrational animals fear (fear is a passion, which results when the animal’s sense appetite is moved by the perception of an intention), and the (nonrational) animal psyche (and all psychic powers of the nonrational animal) is corporeal without remainder (Lombardo, _Logic of Desire_ 24).
However, for Thomas “abstract thinking,” or what he would call “universal reason” occurs only in rational animals, and is an activity which takes place in and through the immaterial intellect, which is thus not spatially localizable.
However, does it necessarily follow from this claim that “universal reason” is unrelated to local parts of the brain? I don’t think so. It may well be the case that a specific part of the brain is necessary for universal reason to take place. (After all, the same thing can be said for the external senses, which are spatially localizable.)
