The online debate about free will is heating up, thanks to high profile author Sam Harris's new book on the subject. The Chronicle of Higher Education had a nice forum on free will yesterday, starting with an essay by Jerry Coyne. Hilary Bok and Al Mele write in defense of compatibilism, but not in response to Coyne. His argument is very simple. Restating a bit, the idea is that any mental event, M, must be identical to some brain event N. Brain events lawfully necessitate further events in the brain and body. So whatever thought or behavior actually happens after M, nothing else could have happened. So at least in one important sense, the owner of M isn't free.
If we can't rebut this argument (wouldn't it be nice?), maybe we can get more comfortable with it than it first appears. If I know my daughter is thinking if p then q, and p, then I can predict fairly confidently that she will think q. Why? Because the mental has a certain sort of lawfulness, independent of the underlying physical stuff that makes it up. Like you can know things about a sphere, regardless of what it's made out of, you can know things about thoughts, without knowing anything about their physical composition. If you want to feel free from something, you can feel free from your brain, like a ball could feel free from being made of plastic or mud or ice (if balls could think). It's going to have the same geometry, regardless.
Hey, it's something ...
How is it that the laws of neuroscience, and ultimately physics, govern what happens in our brains, but the laws of thought do as well? Why do these two sets of laws mesh with each other? When you say mental states are brain states, it's not time to retire, because everything's now nice and clear. You actually wind up with a lot of new and difficult things to think about.