I have a genetic condition. People like me are prone to violent fantasy and jealous rage; we are over 10 times more likely to commit murder and over 40 times more likely to commit sexual assault. Most prisoners suffer from my condition, and almost everyone on death row has it. Relative to other people, we have an abundance of testosterone, which is associated with dominance and aggression, and a deficit in oxytocin, associated with compassion. My sons share my condition, and so does my father.
So, yes, I am male. The neuroscientist David Eagleman uses this example to illustrate how our genetic blueprint partially determines our actions, including our moral behavior. The rest is determined by our environments; by the forces that act upon us throughout our journeys from zygotes to corpses. And this is it—we are physical beings, and so our natures and our nurtures determine all that we are and all that we do.
This conclusion does not feel right. Common sense tells us that we exist outside of the material world—we are connected to our bodies and our brains, but we are not ourselves material beings, and so we can act in ways that are exempt from physical law. For every decision we make—from leaning over for a first kiss, to saying “no” when asked if we want fries with that—our actions are not determined and not random, but something else, something we describe as chosen.
This is what many call free will, and most scientists and philosophers agree that it is an illusion. Our actions are in fact literally predestined, determined by the laws of physics, the state of the universe, long before we were born, and, perhaps, by random events at the quantum level. We chose none of this, and so free will does not exist.
I agree with the consensus, but it’s not the big news that many of my colleagues seem to think it is. For one thing, it isn’t news at all. Determinism has been part of Philosophy 101 for quite a while now, and arguments against free will were around centuries before we knew anything about genes or neurons. It’s long been a concern in theology; Moses Maimonides, in the 1100s, phrased the problem in terms of divine omniscience: If God already knows what you will do, how could you be free to choose?
More important, it’s not clear what difference it makes. Many scholars do draw profound implications from the rejection of free will. Some neuroscientists claim that it entails giving up on the notion of moral responsibility. There is no actual distinction, they argue, between someone who is violent because of a large tumor in his brain and a neurologically normal premeditated killer—both are influenced by forces beyond their control, after all—and we should revise the criminal system accordingly. Other researchers connect the denial of free will with the view that conscious deliberation is impotent. We are mindless robots, influenced by unconscious motivations from within and subtle environmental cues from without; these entirely determine what we think and do. To claim that people consciously mull over decisions and think about arguments is to be in the grips of a prescientific conception of human nature.
I think those claims are mistaken. In any case, none of them follow from determinism. Most of all, the deterministic nature of the universe is fully compatible with the existence of conscious deliberation and rational thought. These (physical and determined) processes can influence our actions and our thoughts, in the same way that the (physical and determined) workings of a computer can influence its output. It is wrong, then, to think that one can escape from the world of physical causation—but it is not wrong to think that one can think, that we can mull over arguments, weigh the options, and sometimes come to a conclusion. After all, what are you doing now?
Paul Bloom is a professor of psychology and cognitive science at Yale University. His next book, Just Babies: The Origins of Good and Evil, will be published next year by Crown. You can follow him at @paulbloomatyale.
