Does free will exist?
The question of whether free will exists has been of interest to philosophers for more than two millenia. Over the last few years, the free will question has also grabbed the attention of psychologists and neuroscientists. There’s been a spate of articles claiming that science has demonstrated that free will is nothing but an illusion, or, conversely, that neurobiology lends support to the claim that we are free, morally responsible agents.
Either of these views might turn out to be correct. But in philosophy (as well as in science) it is important to be right for the right reasons, and this is precisely where many of these treatments of the free will problem fall down. To anyone versed in the relevant philosophical literature, these scientific discussions of the free will problem are often achingly naïve.
This is unnecessary. Scientists don’t have to be philosophically unsophisticated. Indeed, the better a scientist’s grasp of philosophical theories and methods, the more likely she is to do good science, because she will be sensitive to the subtle conceptual issues and uninterrogated assumptions that play a role in her empirical work.
In this and in my next few blog postings, I’m going to set out the so-called free-will problem and consider the main options for addressing it. Think of it as Free Will 101—a very basic introductory course for anyone interested in the controversy about freedom of the will and who wants to make an informed assessment of scientists’ claims and counter—claims about it.
The free will problem is usually set out as a question about whether freedom is possible in a deterministic universe (later on we’ll see that this is something of an oversimplification).
Here’s the idea. Leaving aside the special case of quantum events (we’ll consider these later on), it looks like everything that happens has a cause. Things don’t just happen for no reason—something always makes them happen. We all rely on this assumption in our practical dealings with the world. For instance, when you slip your key into the ignition of your car and turn it, you have every reason to be confident that this action will cause your car to start, and if you car doesn’t start, you have every reason to assume that its failure to start has a cause as well (for instance, that the battery went dead, and that this was caused by your having left your headlights on all night).
The thesis that everything that happens is caused by previous events is known as determinism. Let’s consider some of its implications….
- If determinism is true, then every event is part a vast causal web. Think of events as falling dominos in a long line of dominos stretching far back into the past and disappearing over the horizon of the future.
- If every event is caused by prior events, this must include the events that go on in people’s minds. The choices that we make are events, so they, too, must be caused by prior events, which were themselves caused by prior events, and so on, right back to the Big Bang.
- Cause—effect relations conform to the laws of physics. So, an infinitely powerful intelligence (an intelligence with a complete knowledge of the laws of physics and a complete knowledge of the physical properties of every object in the universe) could predict the entire future of the universe, including every choice that every person will ever make, with 100% accuracy.
- Notice that I said “an infinitely powerful intelligence.” Determinism doesn't imply that everything that will happen is, in practice, predictable. It's a thesis about how things are rather than what we can know about them.
- If determinism is true, then if God were to rewind time to some arbitrarily chosen moment and then push the “play” button, events would unfold in exactly the same way that they did the first time around, right down to the tiniest detail. One way to express this idea is to say that if determinism is true, then there is only one physically possible future.
That’s roughly the deterministic picture of the universe. Would freedom be possible in such a universe? And if freedom exists, does this mean that our choices somehow escape the deterministic web? We’ll begin to explore these questions in my next blog posting.