Well, I'll Never Be Allowed To Teach At TAC Now!
"So what!" I hear someone yelling. Well the point is about the immortality of the soul. A pretty important concept in the Thomistic system. If I am not mistaken, Thomas premises the soul's immortality on the fact that all mental states (to use the modern term for the soul) are super physical. Yet he beautifully avoids Cartesian dualism.
Now, what if every mental state is found to correspond to a physical state? Which, of course, modern science has done. It is important to note, that what has not been shown is that universal mental states correspond to universal physical states, but that particular mental states thus correspond. What now? It seems Thomas' premise is wrong. Are we left with materialism?
Well no, because materialism doesn't work. Modern philosophy comes to the rescue in the form of identity theories. See especially Donald Davidson's Mental Events, and David Lewis' An Argument for the Identity Theory is helpful too. For Davidson, mental events are identical with physical events, but that does not mean that we can reduce mental events to physical. There is a logical distinction between the two events although ontologically they are identical (I could be wrong on this point, Davidson is quite hard to read.)
Of course, this has profound implications for Thomistic human nature. This means that the body and soul are only different in ratio and not in rei. Which means that we cannot prove the immortality of the soul. To which I respond "so what!" I think we could learn something from Kant here; we now have a space for faith. This last point, I think, goes too far, and there might be a way out. I'll keep looking.