When I’m flipping a coin to pass the time, and I call “Tails,” what’s going on inside my head? It certainly feels like it was my random choice, and I just as easily could have decided to call “Heads.” Yet there are two other ways to explain my decision.
One is that my decision was directed by some Supreme Being. That hardly seems likely, however. This was an inconsequential decision, and why would God care? More generally, why would a Supreme Being create humans without free will — as if they were the dolls at a little girl’s tea party — and then give them the illusion of free will? That kind of trick would seem to serve no purpose except as an exercise in very un-God-like cruelty.
A second explanation for my coin-flip decision comes from the laws of nature. We are surrounded by events governed by the predictable laws of nature, at least at the human scale of space and time. We can assume that planes will carry passengers across the country, TV sets will show what is happening on the other side of the world, and the microwave will pop your popcorn. Sometimes something will go wrong, but it's not because the laws of nature have been suspended. Despite what we see in the physical world, we have a hard time believing that our decisions are all pre-determined and mechanical. Is it likely that a supercomputer, given all the relevant physical date, could predict yesterday how we'll call the seventh coin toss tomorrow? And what about those times when we break an established routine, or make an adventurous choice, or even go against expectations? Were all those details baked into the universe at the moment of the Big Bang?
Of course, if we don't have free will, we needn't fret over what to believe, since it is pre-ordained. But if we do have free will but believe we don't, well, then we are living out a fantasy. Until science proves that free will doesn't exist (a possibility, but an unlikely one, I think), most people will continue to live as if we do make our own choices.
That doesn't mean that free will is unlimited, of course. We recognize that our choices are influenced and even constrained by our genes and upbringing, as well as by the time and place in which we find ourselves. And we also know that our decisions are realistic only if they can be carried out through physical laws. But, between physical input and physical output, something happens that is in harmony with physical law, but is not dictated by physical law. Free will is the everyday evidence of a non-physical part of our reality.
