This problem is monumental to me. If there is anything that might convince me of the supernatural other than a direct miracle, it is this: if we are nothing more than the sum of our parts, and we are just purposeless bags of atoms, then each and every thought we have and each and every action we take is predetermined. This is not simply a claim that we are deterministic chemical reactions- this is much more sinister. This is a claim that the totality of history, human and otherwise, is the way it is because it could not possibly have been any other way. Our fate was sealed the moment time itself began, by pure consequence of the position and velocity of every particle in the universe.
At its heart, this is nothing more than an argument from causality. If every event must have a cause, and each cause is itself an event, then we're stuck in this infinite backwards loop of causes piling on top of each other until we run into the origin of the universe. As far as I can see, the only way to claim anything other than strict determinism is to make a claim that the human soul (call it the mind, if you're more comfortable) is itself an uncaused cause (or at least has the ability to spawn uncaused causes). It must be something beyond the laws of physics, beyond even the laws of rationality (for the irrationality of an uncaused cause is not limited to the physical world). Choice itself seems to derive from the theory that humans are by their very nature extra-physical.
I should note that quatum mechanics has introduced the possibility of true randomness into the universe- and therefore *might* negate this argument of determinism. I don't think I'm enough of an expert to comment meaningfully on whatever definition of "random" the physicists are using, but I will say that I don't think this solves our problem. Our complaint about determinism is in the lack of choice, not in the method of determination. It is a complaint that "I" the moral agent have no say in any of it. And picking randomness instead of the original state of the universe as our action selector does not solve this problem.
Here's the thing: I think I might believe in free will more than I believe in my conception of rationality. One of the ways you reject epistemology is when it necessarily yields a conclusion that you cannot or do not accept- sort of like a proof by contradiction in math. Over the course of the last few weeks, I've become convinced that Physicalism necessarily leads to both Nihilism and Determinism (many people do not agree with me, but that is my conclusion nonetheless). This leaves me, then, with Dualism. And I see no reasonable formulation of dualism that does not include the supernatural (I may not be using the most precise definition here, but my idea of the supernatural isn't really noticeably different then the technical definition of dualism). Or perhaps more accurately, whether or not we call it "supernatural" is not my chief concern- rather, the fact (or my belief) that something beyond the physical and measurable exists at all opens up a whole universe of possibilities.
I can see the horrified reaction of the Atheist now. It is the same reaction I would have had just a month ago. My decision appears not to be based on reason, but on something else. Some conviction of a real truth that I have no evidence for. This is partially true. There are some interesting arguments for dualism made, if you review that link to the Wikipedia page, which I do find reasonably compelling. But in the end, I do think you can construct a coherent view of reality from Physicalism- it's just a reality I don't particularly want to live in. So in a way, I'm rejecting the idea because I just can't stomach it as much as I am because it strikes me as wrong. I'm certainly not rejecting it because I find any holes in the reasoning I used to get there. I'm not quite sure if this qualifies as rational or irrational. But I do wonder how Christians would feel about me believing- that is, professing and acting- out of a rejection of the opposition rather than an acceptance of their doctrine?
Does this mean I'm an Agnostic now? Maybe. I've mentioned before that I don't think you should make big life decisions while in an emotional state. I'm going to sit on this for awhile and see if I don't reach any new conclusions over the next few weeks. But right now it's looking like I'm going to have to change this blog's tagline.