Has Neuroscience Proven There Is No Free Will?


These days you may indeed be told that experiments conducted by neuroscientists and psychologists have proven that free will is an illusion. I always snicker when someone tells me this because it means that they did not come to that conclusion freely, but were determined by their brain chemistry. But, leaving that aside, how should we answer these challenges to free will?

Philosopher Edward Feser, in a book review written for City Journal, denies neuroscience has done any such thing. Feser is reviewing Free: Why Science Hasn’t Disproved Free Will, by Alfred Mele, and he claims that “Mele demonstrates that scientific evidence comes nowhere close to undermining free will, and that the reasoning leading some scientists to claim otherwise is amazingly sloppy.”

Feser first tackles the work of neurobiologist Benjamin Libet. If you’re not familiar with Libet’s work, here is a summary:

In Libet’s experiments, subjects were asked to flex a wrist whenever they felt like doing so, and then to report on when they had become consciously aware of the urge to flex it. Their brains were wired so that the activity in the motor cortex responsible for causing their wrists to flex could be detected. While an average of 200 milliseconds passed between the conscious sense of willing and the flexing of the wrist, the activity in the motor cortex would begin an average of over 500 milliseconds before the flexing. Hence the conscious urge to flex seems to follow the neural activity which initiates the flexing, rather than causing that neural activity. If free will requires that consciously willing to do something is the cause of doing it, then it follows (so the argument goes) that we don’t really act freely.

The argument is that we don’t detect the conscious urge to flex our wrist until after we have sent instructions to flex our wrist, so we can’t be freely deciding to flex our wrist. Is this argument valid? Hardly.

As Mele shows, the significance of Libet’s results has been vastly oversold. One problem is that Libet did not demonstrate that the specific kind of neural activity he measured is invariably followed by a flexing of the wrist. Given his experimental setup, only cases where the neural activity was actually followed by flexing were detected. Also, Libet did not check for cases where the neural activity occurred but was not followed by flexing. Hence we have no evidence that specific kind of neural activity really is sufficient for the flexing. For all Libet has shown, it may be that the neural activity leads to flexing (or doesn’t) depending on whether it is conjoined with a conscious free choice to flex.

But there are other problems with the experiment “proving” free will doesn’t exist.

There’s a second problem. The sorts of actions Libet studied are highly idiosyncratic. The experimental setup required subjects to wait passively until they were struck by an urge to flex their wrists. But many of our actions don’t work like that—especially those we attribute to free choice. Instead, they involve active deliberation, the weighing of considerations for and against different possible courses of action. It’s hardly surprising that conscious deliberation has little influence on what we do in an experimental situation in which deliberation has been explicitly excluded. And it’s wrong to extend conclusions derived from these artificial situations to all human action, including cases which do involve active deliberation.

Even more fundamentally, why should we tie the conscious feeling in our brain that we made a decision with the fact that the decision was freely made?

Even if the neural activity Libet identifies (contrary to what he actually shows) invariably preceded a flexing of the wrist, it still wouldn’t follow that the flexing wasn’t the product of free choice. Why should we assume that a choice is not free if it registers in consciousness a few hundred milliseconds after it is made? Think of making a cup of coffee. You don’t explicitly think, “Now I will pick up the kettle; now I will pour hot water through the coffee grounds; now I will put the kettle down; now I will pick up a spoon.” You simply do it. You may, after the fact, bring to consciousness the various steps you just carried out; or you may not. We take the action to be free either way. The notion that a free action essentially involves a series of conscious acts of willing, each followed by a discrete bodily movement, is a straw man, and doesn’t correspond to what common sense (or, for that matter, philosophers like Wittgenstein or Aquinas) have in mind when they talk about free action.

Mele tackles other science that purports to disprove free will in his book. Given Feser’s review, this book may be well worth reading.

  • barry

    “These days you may indeed be told that experiments conducted by
    neuroscientists and psychologists have proven that free will is an
    illusion. I always snicker when someone tells me this because it means
    that they did not come to that conclusion freely, but were determined by their brain chemistry.”
    ————I don’t see why you snicker. Do bugs have freewill? No. Can they still draw correct conclusions about the world? Yes.

  • Rachel Waller

    What makes you think they don’t have free will? Why wouldn’t they?

  • barry

    Well most Christians tie freewill into “spirit” (i.e., since the “image of God” man has in Genesis 1:26 likely isn’t physical image, most Christians understand this to mean that man’s capacity to make informed choices is his “freewill”), and thus an attribute that is the image of God, and thus a uniquely human attribute. Therefore, under the Christian understanding, bugs do not have freewill.

    My point was that if bugs don’t need freewill to correctly interpret the world around them, then humans don’t need freewill to correctly interpret the world around them either, which means even if our conclusions are determined solely by brain chemistry, there is no reason why this should imply that we can never have reasonable certainty about the world outside of ourselves.