I am going to be getting back to The Christian Delusion next week, but you see this week I am teaching a 1 week intensive course in systematic theology so I’m trying to find time merely for something short and delightful for y’all. (1 week intensive courses are, for the professor, the closest equivalent of an Ironman race which, when you think about it, really should be an Ironperson race.)
Let’s look at Robert Gressis’s comment: “three days a week I’m a materialist w/r/t our minds and the other four I’m not, but all seven days I find the notion that all our thoughts and actions are fully determined to be almost impossible to believe.”
I agree with Robert on that last point. The notion that all my actions are physically determined is, for me, a claim that is refuted as easily as appealing to one of G.E. Moore’s appeals to good sense. I say: “Arm rise!” and lo and behold my arm rises. Amazing that, and all the more amazing because it strikes us as so mundane. I am an actor, intervening freely in the chain of physical causes, moving atoms about by the sheer force of will every moment as I type this on my keyboard.
One of the innumerable challenges for naturalists is to provide some account of this datum — libertarian free will — that is congruent with naturalistic assumptions. You see, the problem is that you need a non-physical substance to be the actor because the physical substance — the brain — will never provide you with free will.
Think about it like this. My index finger pushes the “h” key on the keyboard (to make this point). What is the explanation of the event? The brain-based explanation traces back to a pattern of neurons firing in that 3 pound lump of soggy grey matter between my ears. But that explanation — the neurons shooting off — completely misses the uniquely interesting part of the explanation — the mental intention to make a point by pushing the h key. Only if you have a mental substance that is the ground of explanation can you have libertarian free will. The bad news for our naturalists is that, as Billy Joel sang some years ago, it’s all about soul. In fact that’s a real embarassment. Because just as a spinning earth does not belong in a geocentric universe so a soul does not belong in a naturalist’s world.
So we must make a choice. Shall we retain a blind, dogmatic commitment to one or another form of naturalism? Or admit the obvious that we have free will and accept with it a mental substance as the ground of free action? I know where I’ll put my money.

