I just finished reading Free Will by Sam Harris. (quickest. read. ever.) In it, Harris makes the argument that free will is an illusion. Despite my best efforts, I can’t help but agree with him. Free will must be an illusion.
Thinking about whether we have free will is a bit like thinking about time travel. Soon enough, the mental gymnastics and potential paradoxes are enough to make your brain explode. Having thought about the topic a bit before reading the book, I was not surprised by any of Harris’s statements of conclusions, but he certainly stated them with greater precision and eloquence than I could think them.
The essence of the argument goes something like this (to use a mundane example):
I chose chocolate ice cream over vanilla. I did so of my own free will, because I could have chosen vanilla.
But in reality, my decision was based upon my having weighted chocolate as preferable to vanilla in my brain. I have taste preferences and memories of eating chocolate versus vanilla, all of which are encoded in my brain. For whatever reason, at the moment that I made my decision, the factors weighing in favor of chocolate were stronger than those weighing in favor of vanilla, and my decision was a product of those factors. But I do not, and cannot, know why those factors weighed as they did at that time. But if the tape of time were rewound, my brain would have always made exactly the same decision. I really had no choice in the matter. Tomorrow, I might pick vanilla over chocolate, but that too will be the necessary product of my prior thoughts. I might look back at my decision to pick chocolate today as a good (or bad) decision, but that reflection does not suggest that I was actually free to make it.
The scientific view of the brain is that it is a (very complex) biochemistry machine. And if we are reducible to the molecules that make us up, there is simply no escaping the fact that every decision we make is an obligate outcome of the conditions that preceded it. In fact, it is clear from imaging studies that our brains make decisions before we are consciously aware of it. Thus, our decisions can in principle be predicted before we are even aware of them, which seems to directly negate the idea that any decision is a conscious one.
Even putting aside the purely materialist view of the mind, the notion of a non-material “soul” does not solve the problem. I know I chose chocolate because the factors weighing in its favor were greater than those weighing against at the time I made my decision, and I cannot controls those factors, so whether or not there is such a thing as a soul is irrelevant to my choice (or any other). Further, even if one argues that God helps to program our souls to choose the best path, then one is simply substituting inputs from God for inputs from our environment, and the problem is not solved. No matter what decision we make on what topic, one can always iteratively ask “And where did that decision come from?” This will always take us back to starting conditions that are wholly out of our control, soul or no soul.
The rejection of free will has a number of necessary consequences. One is that the notion of “sin”, and of God meting out eternal reward or punishment for our actions, is fundamentally unjust. In general, the idea of “retributive justice,” which is based on punishment for our actions, is an oxymoron–it is not just at all. This is not to say we should let murderers and rapists walk free. We might lock them up to protect society from their future actions, or to change their own mental states to make them less likely to commit that or another crime in the future (rehabilitation), or to change the mental states of others to make them less likely to commit such crimes (deterrence). But the idea of punishment for an action simply falls on its face. Play the tape backwards, and the murderer still murders. His actions do not reflect a choice on his part; rather, they reflect who he fundamentally is, since his actions are the product of his genes, his history, his environment, and probably a bit of random chance as well.
So we might act as if we have free will, and we might think we have free will, but in reality, it is probably just an illusion; if there is a compelling argument to be made that we do have free will, I have not heard it.