This off-the-cuff post on atheism generated some interesting discussion with Gaius about physicalism, reductionism, and humanism, among other things. I don’t know that I can express my views on the matter better than I tried to do in this post from a few years ago discussing Keith Ward’s Pascal’s Fire. In short, we often abstract from the phenomena of experience in order to provide a more precise mapping or modeling of certain aspects of reality for various purposes; the error of reductionism is to mistake those abstract models for the whole of reality itself. (Huston Smith once compared it to thinking that an increasingly detailed map of Illinois will–eventually–result in a map of the entire United States.)
Physicalism and reductionism are frequently seen as threats to religious belief. This can be for a variety of reasons, such as that they seem to undermine belief in an immaterial (and possibly immortal) soul, or that they deny the “specialness” of human beings. However, I do think it’s possible for a Christian to affirm a non-reductive version of physicalism. This would mean that human beings are physical beings with consciousness, feeling, and rationality. These are genuinely “emergent” features of the world–features that appeared over the course of evolutionary history and which we share with other animals, but they are not reducible to the physico-chemical aspect of reality. They are not simply the outworking of their underlying material substrate but exert a genuine causal influence on the world. Philosophers and theologians have characterized how this might work in a variety of ways, such as “whole-part” or “top-down” causation. But the point is that the mental introduces genuine novelty into the world and is capable of affecting the course of events. Moreover, if something like this is right, it seems possible that God could, at death, preserve whatever it is that constitutes each person’s unique selfhood (e.g., memories, character traits) and “translate” them into some other medium, whether embodied or not.