[This is an edited extract from Freedom Regained: The Possibility of Free Will, University of Chicago Press. Not to be reproduced without permission of the publisher.]
We’ve heard a lot in recent years about how scientists — neuroscientists in particular — have “discovered” that actions in the body and thoughts in the mind can be traced back to events in the brain. In many ways it is puzzling why so many are worried by this. Given what we believe about the brain’s role in consciousness, wouldn’t it be more surprising if nothing was going on in your brain before you made a decision? As the scientist Colin Blakemore asks, “What else could it be that’s making our muscles move if it’s not our brains?” And what else could be making thoughts possible other than neurons firing? No one should pretend that we understand exactly how it is that physical brains give rise to conscious thoughts and perceptions, but nor should anyone doubt that in some sense they do.
However, because we don’t yet understand the relationship between mind and brain, we don’t yet know how to talk about it. The words and phrases we reach for when talking about the mind are often inadequate and misleading. For instance, I and others sometimes talk about brains “causing” or “giving rise to” thoughts and perceptions. That suggests that brains are doing all the real work and that thoughts and perceptions are in some sense mere effects of neural causes, a view known as epiphenomenalism.
Do the scientific facts about brains require us to think of thoughts and actions in this way? I don’t think they do. The undeniable fact is that brains provide the material means by which conscious life is sustained. Without brains there can be no human consciousness. But it does not follow from this that we can explain all human behavior in neurological terms alone and that conscious thoughts contribute nothing to our actions. That is a much stronger claim, which goes against the evidence of experience.
Take a simple example. I shout to you “duck!” and you duck. Home in on the brain and it may well be possible to trace a line of cause and effect which only describes sound waves entering your ear, translated into brain signals, in turn triggering further neural firings that lead to your muscles moving in such a way that you duck. We will not find embedded in any of this the meaning of “duck.” However, it seems deeply implausible to suggest that we can make sense of what happened here unless we accept that the meaning of “duck” had a vital role to play in the causal chain. If I had shouted “suck!”, “cheese!” or “jump!,” you would have reacted differently. We cannot then understand your behavior unless we ascribe some critical importance to the meaning of “duck.”
That can only mean one of two things: either the meaning of “duck” had no role at all to play in your action, or a purely physical description of what went on would not provide a complete account of why you did what you did, adequate to explain what happened. Given how implausible the first option is, we should be very careful before rejecting the second.
The thesis we are questioning here can be summed up as the claim that thoughts have no causal efficacy: they do not affect what we do. “Thoughts” should be understood very broadly here to include not just beliefs, but also desires, intentions and simply the way in which we understand what we see and hear, like injunctions to duck.
When people deny the causal efficacy of thoughts, they often do so on the basis of experiments that at most show that thoughts do not affect actions in certain very specific cases. To jump to the general conclusion that thoughts never affect actions looks like a remarkable example of rash generalization. The Libet experiments, for example, appear to show that conscious choice doesn’t determine when we choose to move a finger in a laboratory situation. Even if this is true, it seems too much to leap from this to the claim that, for instance, the belief that immigrants are taking over the country is not a reason why a person voted for a nationalist political party. An experiment which shows that “thoughts have no causal efficacy here” cannot show that “thoughts have no causal efficacy anywhere.” That would be like claiming that because a person’s religious belief does not affect their choice of soap powder, it doesn’t affect their choice of spouse or place of worship.
The analogy is perhaps less exaggerated than you might think because, as a matter of fact, many experiments that appear to debunk the role of conscious thought in action focus on very specific kinds of action that are not particularly reason- or thought-based. The philosopher Shaun Nichols offered me as an example a famous study by John Bargh, in which subjects who were made to read passages that included words associated with old age subsequently walked more slowly than subjects who weren’t. None of these people were aware that they were altering their behavior, or had any suspicion that what they had read was changing how they moved.
“Some people are shocked that people’s behavior can be affected so much by things they are unconscious of,” Nichols told me. But thoughts do not generally play a significant role in how we walk, unless we are deliberately acting or adjusting for some particular reason. So typically, if you ask someone why they walked more slowly than usual to an elevator, they don’t know. “But what if you asked them, why did you walk to the elevator?” asks Nichols. “It’s not going to be like, ‘Jeez, I don’t know, maybe it was to get out of the building?’ They know why they walked to the elevator. If somebody is at an airline gate, and you say, ‘Why are you here?’ they don’t say, ‘Gee I have no idea why I’m here.’” No experiment has ever shown that people’s beliefs have nothing to do with actions of this kind. So “if you’re going to draw big inferences about the nature of human decision making from studies about the foibles, it’s really important to keep in mind all of the things we do astonishingly well, so well that you could never publish an experiment because the editor would just say, ‘Well of course people know that they’re at the gate because they need to get a plane!’”
Work by the psychologists Kathleen Vohs and Jonathan Schooler also seems to show that thoughts do affect actions. Specifically, the belief that you have free will makes you act more morally, and the belief that you lack it makes you act worse. In two experiments, they found that subjects who had read a passage which “portrayed behavior as the consequence of environmental and genetic factors” cheated more on a subsequent task than those who had read a neutral passage. They also found that “increased cheating behavior was mediated by decreased belief in free will.” Others have found similar results. This seems as clear an example as any of a belief affecting action.
Perhaps the neatest and most powerful rejoinder to the idea that thoughts change nothing comes from the neuroscientist Dick Swaab, who dismisses free will out of hand as a “pleasant illusion.” Nonetheless, in his book We Are Our Brains he reports that “patients suffering from chronic pain can be coached to control activity in the front of the brain, thereby reducing their pain.” But hang on: if “we are our brains” how can we control them? His own example is evidence that it is far too simplistic to talk as though our brains are doing all the work and conscious thought is redundant.
For all the clever research showing how we are manipulated by unconscious processes, much of what we do is patently rooted in thoughts, reasons and beliefs. No credible scientific view of mind can force the conclusion on us that thoughts have no role to play in guiding our actions. How they do so, however, is not so easy to explain. One possibility is that consciousness is somehow a property of physical stuff, whether it is a part of a brain or a table. If this were true, it would be odd if only some elements, like carbon, had this property. Therefore almost everyone who believes consciousness is a property of matter is a panpsychist, believing that mind or consciousness is a feature of all physical matter. Mind is everywhere.
This sounds crazy. Surely stones don’t think? Well no, and most panpsychists don’t claim they do either. Only remarkably complicated physical structures like brains can think in any recognizable sense because thinking, as we know it, requires more complexity than the structure of the stone allows. Nonetheless, panpsychism does entail that there is some kind of trace of mind, some minimal subjective awareness, even in a pebble.
Many philosophers have ruled this possibility out because it seems that subjective awareness is just not the sort of thing that could ever be the property of brute matter. But maybe this is simply a lack of imagination. Matter may not be so brute after all and believing that it is may be as ignorant and prejudiced as believing that “brutes” like pigs and dogs cannot feel pain. The contemporary panpsychist Galen Strawson, for example, says that nothing in physics rules out the possibility that something physical cannot have experiences. “To claim to know with certainty that spatio-temporal extension entails non-experientiality is to claim to know more about space-time than is warranted by anything in science.” He accuses many materialists of being “false naturalists” in the grip of “the conviction that experience can’t possibly be physical, that matter can’t possibly be conscious.” Ironically, this is an assumption shared with Descartes’ dualism, which asserts that the world is made up of two different substances, matter and mind. Indeed, it is doubly ironic because as Strawson points out, “Descartes was at bottom aware that one can’t rule out the possibility that matter may be conscious. Many of the false naturalists, by contrast, have no such doubts.”
Strawson may be right about this. Weirdness is not, after all, a sure sign of falsity. As biologist J.B.S. Haldane famously said, “the Universe is not only queerer than we suppose, but queerer than we can suppose.” That may be so, but many, including myself, find it very hard to even understand what the panpsychist claim really adds up to. The choice, it seems, is between a view that is ludicrous or empty, as Colin McGinn put it. If it is the claim that stones think, it is ludicrous. If it is the claim that any atom could be part of something that does think, then it is empty, because this is what anyone who thinks brains are required for consciousness believes. So although panpsychism cannot be ruled out, it remains an explanation of last resort for the consciousness of physical beings.
A more promising alternative appeals to the idea of different levels of explanation. To take a mundane example, when I hit the “#” key on my keyboard, an “#” symbol appears on my screen. There must be some explanation of this at the very lowest, sub-atomic level, involving nothing more than chain reactions between electrons, neutrons and protons. That might appear to be the most fundamental explanation of all. But of course it isn’t the only one and for practical purposes it isn’t the best. Far preferable is the one that refers to the code written into the computer software. When I press the key, a digital signal is sent which passes through a program, resulting finally in a digital signal which “tells” the monitor which pixels to blacken out. To say that the “real” explanation is the sub-atomic one and that the existence of code does nothing to explain what happens would not just be wrong but perverse.
When it comes to our minds and behavior, there are explanations at the level of conscious thought, the biochemical brain, and of fundamental physics. If we took seriously the reductionist idea that the only true explanation of why things happen is to be found at the most basic, lowest level, then not even brain science would be “really” explaining behavior. Physics rather than psychology or neuroscience provides the ultimate reductionist account of why things happen.
We do not have to decide which of atoms, brains or thoughts provide the “real” explanation for what we do. We simply need to accept that there are different accounts we can give at each level, and which is most appropriate depends on what we are trying to understand or explain. This notion of appropriateness can be understood in a purely pragmatic sense. You could believe that in principle a physicist with powers of Laplacian omniscience could describe everything that a person has done on the basis of physical information alone. But because in practice this is never going to be possible, you might accept we still have use for the explanations of psychologists and neuroscientists.
However, there is increasing evidence that scientific explanations don’t work as neatly as this after all. The old reductionist paradigm was that the way to understand how anything works is to break it down and down until you get to the most fundamental processes. In other words, the complex whole can be entirely explained through the workings of the simpler parts. This has commonly been understood to imply the theoretical possibility of reconstructing from the bottom up as well as deconstructing from the top down: if you know what the atoms are doing you’ll know what the larger objects made up of them will do. But the Nobel-prize winning physicist Philip W. Anderson suggests this is a widespread mistake. “The reductionist hypothesis,” he says, “does not by any means imply a ‘constructionist’ one: the ability to reduce everything to simple fundamental laws does not imply the ability to start from those laws and reconstruct the universe. In fact, the more the elementary particle physicists tell us about the nature of the fundamental laws, the less relevance they seem to have to the very real problems of the rest of science, much less to those of society.”
Science increasingly seems to be confirming the old adage that the whole is greater than the sum of its parts. For instance, you can look at how the brain works and in theory describe everything that goes on in terms of fundamental particles. But you cannot look only at the laws governing the behavior of particles and from that work out what will happen when they are arranged into complex organs like brains. The laws of physics do not predict consciousness, yet that is what the physical universe gives rise to.
To put it another way, systems behave in ways which cannot be predicted simply by knowing the behavior of the elements of the system. Systems acquire characteristics which their simple parts do not have. A swarm of bees can be deadly even though no bee in it is lethal; an orchestra can play a piece of discordant music even though each instrument by itself is playing harmoniously; five functional human beings can form a dysfunctional group. As another Nobel-prize winning physicist Robert Laughlin put it, “what we are seeing is a transformation of worldview in which the objective of understanding nature by breaking it down into ever smaller parts is supplanted by the objective of understanding how nature organizes itself.”
This new understanding is known as complexity theory. “A complex system is composed of many different systems that interact and produce emergent properties that are greater than the sum of their parts and cannot be reduced to the properties of their constituent parts,” as the scientists Nicolis and Rouvas-Nicolis put it. Or, to take psychologist Michael Gazzaniga’s account of “emergent properties,” micro-level complex systems “self-organize … into new structures, with new properties that previously did not exist, to form a new level of organization at the macro level.” In “strong” versions of this theory, “the new property is irreducible, is more than the sum of its parts, and because of the amplification of random events, the laws cannot be predicted by an underlying fundamental theory or from an understanding of the laws of another level of organization.”
To give a clear example, if this is correct, quantum physics is more fundamental than Newtonian physics, but Newton’s laws can’t be torn up and replaced by quantum ones. “Classical properties, such as shape, viscosity, and temperature, are just as real as the quantum ones, such as spin and nonseparability,” says Gazzaniga.
Gazzaniga is interested in how complexity provides a way of understanding how minds operate in ways that can’t be either predicted or understood by only studying brain processes. Mind and consciousness are “emergent properties” which arise out of nothing more than brain processes, because the complex organization of these processes creates new properties which are not found at the fundamental physical level.
This explains how it can be that beliefs, desires and intentions can actually change things, without us having to think that they are mysterious, non-physical things. “Mental states that emerge from our neural actions do constrain the very brain activity that gave rise to them,” explains Gazzaniga. “Mental states such as beliefs, thoughts, and desires all arise from brain activity and in turn can and do influence our decisions to act one way or another.”
This is one of the most important scientific facts we need to bear in mind when thinking about free will. Too often it can seem that, if brains are the engines of thought, then thoughts themselves cannot change anything. Complexity theory shows us how this can be false, without the need to postulate any strange, weird, supernatural or non-physical will or soul. It shows that the idea that thoughts, beliefs and desires can cause things to happen is not outmoded metaphysics, but bang up-to-date science.
I’m fairly sure that the right way to understand the apparently self-evident fact that thoughts do change what we do will involve thinking about levels of explanation rather than adopting panpsychism. I’m less sure whether that will be because we cannot in practice do without explanations at the psychological level or because we cannot in principle explain everything at the most fundamental physical level. My bet would be on the latter, or a third possibility I can’t even imagine. However this debate resolves itself, we already understand enough to see that accepting that in some sense our thoughts and actions are only possible because of our brains should not trouble us. Neuroscience is filling in details of the naturalist picture, but there is plenty of room for human agency in it.
Julian Baggini is Founding Editor of The Philosophers’ Magazine. His books include Welcome to Everytown: A Journey into the English Mind, What’s It All About?: Philosophy and the Meaning of Life, the bestselling The Pig that Wants to be Eaten, Do They Think You’re Stupid?, The Ego Trick and The Virtue of the Table: How to Eat and Think, all published by Granta Books.