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The Stone is featuring occasional posts by Gary Gutting, a professor of philosophy at the University of Notre Dame, that apply critical thinking to information and events that have appeared in the news.

Could science prove that we don’t have free will? An article in Nature reports on recent experiments suggesting that our choices are not free. “We feel that we choose,” says the neuroscientist John-Dylan Haynes, “but we don’t.”

The experiments show that, prior to the moment of conscious choice, there are correlated brain events that allow scientists to predict, with 60 to 80 percent probability, what the choice will be. Of course this might mean that the choices are partially determined by the brain events but still ultimately free. But suppose later experiments predict our choices with 100 percent probability? How could a choice be free if a scientist could predict it with certainty?

But my wife might be 100 percent certain that, given a choice between chicken livers and strip steak for dinner, I will choose steak. Does that mean that my choice isn’t free? Couldn’t she be sure that I will freely choose steak?



Perhaps, though, what’s important about the experiments is not that choices are predictable but that they are caused. How could a choice that is caused be free? Wouldn’t that mean that something made it happen? On the other hand, how could a choice that was not caused be free? If a choice has no cause at all, it is simply a random event, something that just occurred out of the blue. Why say that a choice is mine if it doesn’t arise from something occurring in my mind (or brain)? And if a choice isn’t mine, how can we say I made it?

Following out this line of thought, David Hume, for example, argued that a free choice must be caused and that, therefore, freedom and causality must be compatible. (This view of freedom is called “compatibilism.”) Of course, some ways of causing a choice do exclude freedom. If I choose to remain indoors because I’m in the grip of a panic attack at the thought of going outside, then my choice isn’t free. Here we might say that I’m not just caused to choose as I do, I’m compelled. But perhaps I stay inside just because I want to continue reading an interesting book. Here my desire to continue reading causes me to stay inside, but it seems wrong to say that it compels me. So perhaps a choice is free when it’s caused by my desire rather than compelled (that is, caused against my desire). A choice is not free when it’s uncaused but when it’s caused in the right sort of way.

Philosophers favoring compatibilism have worked out elaborate accounts of what’s involved in a choice’s being caused “in the right sort of way” and therefore free. Other philosophers have argued that compatibilism is a blind alley, that unless our choices are ultimately uncaused they cannot be free. These efforts have led to many important insights and distinctions, but there is still lively debate about just what is required for a choice to be free.

Related More From The Stone Read previous contributions to this series.

Figuring out what makes a choice free is essential for interpreting scientific experiments about freedom, but it does not itself involve making scientific observations. This is because “What makes a choice free?” is not a question about facts but about meanings. The fact that I raised my arm can be established by scientific observation—even by the impersonal mechanism of a camera. But whether I meant to wave in greeting or to threaten an attack is a matter of interpretation that goes beyond what we can scientifically observe. Similarly, scientific observations can show that a brain event caused a choice. But whether the choice was free requires knowing the meaning of freedom. If we know that a free choice must be unpredictable, or uncaused, or caused but not compelled, then an experiment can tell us whether a given choice is free. But an experiment cannot of itself tell us that a choice is free, anymore than a photograph by itself can record a threat.

This is not necessarily because freedom is some mysterious immaterial quality that is beyond the ken of science. That may be so, but the essential point is that, at present, we do not have a sufficiently firm idea of just what we mean by freedom to know how to design a test for it. More precisely, we don’t know enough about the relation of free choice to the brain-events that typically precede it. (By contrast, we do, for example, know enough to judge that a brain tumor that triggers psychotic behavior destroys free choice.)

The progress of brain science can give us specific information about how brain events affect our choices. This allows our philosophical discussion of the conceptual relation between causality and freedom to focus on the real neurological situation, not just abstract possibilities. It may well be that philosophers will never arrive at a full understanding of what, in all possible circumstances, it means for a choice to be free. But, working with brain scientists, they may learn enough to decide whether the choices we make in ordinary circumstances are free. In this way, science and philosophy together may reach a solution to the problem of free choice that neither alone would be able to achieve.