Anti-physicalists are often accused by physicalists of trying to sneak God in the back door, or some watered-down version of God, like the soul, or just some notion of the inherent specialness of human beings. While most anti-physicalists do not harbor such hidden agendas, they are sensitive enough to the accusation that they sometimes wrongly neglect branches of inquiry that might seem to lend circumstantial weight to it. One such branch of inquiry is the issue of free will.
The question of free will is one of philosophy's most frequently asked questions. I once believed that either the question was incoherent or the answer was no. People do have some powerful intuitions about free will, though, and it is worth trying to clarify and articulate those intuitions if for no other reason than that the question keeps coming up again and again over the millennia.
In philosophical debates, people generally fall into one of three categories when it comes to the question of free will. First, there is free will eliminativism (there is just no such thing as free will). Then there is compatibilism, which says that while from a scientific point of view, we are effectively deterministic machines, this still allows for any notion of free will worth having. Finally, we have free will libertarianism, which is the whole-hog belief in Free Will (capital F, capital W). Not many people these days admit to being libertarians.
No matter what metaphysical commitments you have, you believe in free will. Not in any grand fundamental sense, but in an everyday sense. Ever been on a diet? Ever looked at the apple you brought as an afternoon snack, but couldn't help thinking about the Snickers bars in the vending machine down the hall in the break room? You know what I'm talking about. The question, then, is what mechanisms implement this.
I am actually pretty sympathetic to compatibilism. No one denies that the mind is very complex, and that there are a good many levels of functional organization between any putatively deterministic molecules bonking around in my neurons and my feeding a sweaty, wrinkled dollar bill into the vending machine. If the free will that we experience turns out to be implemented by a deterministic substrate, way, way down, it would be hubristic to be bothered by this. Who among us can claim to have such a tightly integrated picture of reality across so many levels of organization that it matters to them that their decision to get a second Snickers bar half an hour later and leaving the apple to rot is manifested by zillions of deterministic atoms rather than non-deterministic atoms? In general, however, the debates around free will concern the full-bore libertarian kind. This is the kind of free will that is philosophically interesting, as opposed to (or in addition to) being psychologically interesting, so hereafter that is what I mean when I speak of free will.
As philosophers, we are free to define terms like "free will" any way we choose, but if we stray too far from common usage our speculations become a purely technical exercise. What are the intuitions normal people draw upon when they use the term "free will"? Is free will a quaint human vanity? What are we even talking about when we ask about free will? Can we frame the notion of free will in such a way that it is even coherent yet still respects our rough intuitions? What would a mind have to be like for it to have free will, and how would it work? What kinds of natural laws would there have to be in a universe for us to be able to say that that universe even allowed for any intuitively satisfying notion of free will? Is our universe such a universe? If we philosophers get this wrong, will our justice system crumble, causing society to collapse into brutal barbarism? On this last question, it turns out I am confident that no one - absolutely no one - cares one whit what philosophers think. Do not worry about the social implications of your metaphysics, especially since you can never know how society would interpret it anyway, even if they were to accept it as true.
We all have some ideas about free will and have probably read about it, but before I get into philosophical speculations, I'd like to highlight some of my own off-the-cuff pretheoretical intuitions. There are certain aspects of free will that I think are baked into our common understanding of the term but that for whatever reason, do not get enough explicit consideration in the literature.
Free will is often thought of in terms of action, in terms of how I might impose myself upon the world. This, however, is not a necessary ingredient. Free will, if it exists at all, is an aspect of consciousness, and not at all dependent on my ability to act on it. That is, if we decide ultimately that free will is real, it will be something that I possess even if I am lying completely paralyzed in a hospital bed, as long as my conscious mind is functioning. The kernel of will exists, if it does at all, independent of any ability to impose it upon the world. Lying in the bed, I can allow myself to wallow in self-pity, rage, and despair, or I can decide to spend my time calculating sequences of prime numbers, or I can try to truly forgive everyone who ever wronged me and attain a state of perfect internal peace. These constitute willful decisions, and they are no less willful if I die without ever having recovered the ability to act outwardly upon them, even to the extent of telling anyone else about them.
Free will is too often characterized in terms of selection among a limited set of options: choose one entree from column A and a side dish from column B. While often will manifests itself ultimately as a selection like that, the force behind that selection is an exercise of creative visualization. We envision different outcomes, different futures, different selves, and therein lies the will, even for something as mundane as ordering Chinese food. It is creative will that leads an artist to paint a particular painting in a particular way. Most of us have had experiences of this kind at one time or another - being in that creative groove is an essentially willful state of mind. Will is creative in an unbounded, open-ended kind of way. When an ancient ruler decides that when he dies, a man-made mountain should rise from the desert to be his tomb, and that tens of thousands of slaves should work for decades to make that happen, that is a monumentally willful act. Will is about creating the options in the first place as much as it is about choosing among them.
People often say that I do not have free will if my actions are rigidly determined by the actions of the parts of which I am made. If all the little parts are just doing what they must according to the laws of physics, there is no way the whole could be doing something above and beyond the sum of the parts - the whole just is the sum of the parts. And if the whole somehow had this thing called free will, and this free will had any causal efficacy whatsoever (like the ability to move my arms or legs, or to make my fingers type), it would be a ghost in the machine: somewhere in my body there is at least one molecule that, under the influence of this purported free will, does something different than whatever it would do if it were not under the influence of this free will. That is, if the molecule (or cell, or muscle fiber) were acting only in accord with the physics that govern such things, it would behave one way, but under the influence of free will, it behaves another way. This would seem to imply that free will (of the whole-influencing-the-parts variety) necessarily violates the laws of physics. But no scientist anywhere has seen any violations of the laws of physics at work in the human body or brain.
Free will is most often contrasted with determinism, but this strikes me as something of a false dichotomy, even for a hard-core libertarian. Depending on what we end up deciding free will is, whether or not determinism precludes free will, indeterminism does not save it. Famously, the equations of quantum mechanics, the most successful scientific theory ever, are non-deterministic. That is, they predict outcomes of experiments within a statistical range, but there is always a random factor in the prediction of a particular single trial of an experiment. Moreover, this indeterminacy is generally believed not to be a fault of the equations, gaps to be filled in by future scientists, but a fundamental feature of physical reality.
Some people look hopefully to this indeterminacy of quantum mechanics to give free will a toe-hold in the natural world. There may be something to this, but it is not quantum mechanics' indeterminacy alone that does the trick. If I am made of my parts, if I just am my parts, then I am in the thrall of their functioning, whether those parts function according to deterministic Newtonian physical principles or indeterministic quantum ones. According to my intuitions of what is meant by free will, it buys me no more free will to believe that somewhere in my brain, my decisions are being made by some electron jumping or not jumping to a higher energy orbit within a certain time (no matter how unpredictable beforehand) than to believe that my entire mind functions predictably like a clock.
Moreover, while indeterminism does not by itself save free will, I do not believe that determinism by itself necessarily dooms it. If you made 1000 atom-by-atom copies of me, and each one of them acted in exactly the same way when put in the same situation, it is arguable that it would not necessarily threaten any sense of free will that I may have. My decisions may be freely made, even if I would make the same ones in the same circumstances every time. This may seem initially counter-intuitive, but at least according to my personal sense of the term, free will does not necessarily mean that I have some random X-factor driving my decisions. Some of the most willful decisions we make seem somehow inevitable. Daniel Dennett cites Martin Luther, who, upon taking the possibly suicidal (or worse) stance of denouncing some of the practices of the Catholic Church, said, "Here I stand, I can do no other." Luther's actions were a deep expression of his character. He could not be the person he was and act otherwise. Given who he was, he was bound to do what he did, yet (again, according to my intuitions) his was a quintessentially willful act. When you exercise your free will, you are not merely deciding what to do, you are deciding what to be. You creatively envision a future, and a future self, then you instantiate that future.
This sort of willful determinism is also described quite well by C. S. Lewis (1955) as he recounts the defining moment in his life in which he abandoned his youthful atheism:
I felt myself being, there and then, given a free choice. I could open the door or keep it shut; I could unbuckle the armor or keep it on. Neither choice was presented as a duty; no threat or promise was attached to either; though I knew that to open the door or to take off the corslet meant the incalculable. The choice appeared to be momentous but it was also strangely unemotional. I was moved by no desires or fears. In a sense I was not moved by anything. I chose to open, to unbuckle, to loosen the rein. I say, "I chose," yet it did not really seem possible to do the opposite. On the other hand, I was aware of no motives. You could argue that I was not a free agent, but I am more inclined to think that this came nearer to being a perfectly free act than most that I have ever done. Necessity may not be the opposite of freedom, and perhaps a man is most free when, instead of producing motives, he could only say, "I am what I do."
We define ourselves by our choices. We drag our future selves into existence through our will. William James (1952, p. 288) said, "The problem with the man is less what act he shall now choose to do, than what being he shall now resolve to become."
I think that people feel that determinism threatens free will because it seems to imply that the mind could be accurately modeled by some other system, rendering the will moot. Free will can exist in a world in which the entities having free will act the same way in the same circumstances (i.e. they behave deterministically), but not in a universe in which you could predict that behavior. If my mind is a system that always behaves the same way when it is in state X and given input Y, then any system that could produce that behavior when given input Y in state X for all appropriate behaviors and X's and Y's would be able to second-guess all of my decisions with perfect accuracy. Yet such a system, being nothing but the functioning of its parts, would not be exhibiting free will. It would have no greater identity (none that was causally efficacious, anyway) above and beyond those micro-parts. If the system has no free will and it provably behaves exactly as I do, it certainly seems that any supposed free will that I possess doesn't buy me much.
The threat to free will posed by determinism in such a scenario, though, is not determinism itself, but the fact that it seems to imply that I could be modeled by a system whose behavior is transparently determined by the dynamics of its parts. The problem that determinism poses for free will, then, is that it implies a kind of fundamental, ontological reductionism. However we end up defining me, I may behave the way I do deterministically and still have free will, as long as it is not a reductive determinism, driven exclusively by the functioning of my parts. Conversely, if I am driven strictly by the functioning of my parts, then their being randomized in some way (e.g. according to the principles of quantum mechanics) does not save free will.
Ultimately, the status of free will does not so much depend on whether or not we live in a deterministic universe as it does on whether we live in a universe in which strong, ontological reductionism is true. Regardless of the particular laws that describe the low-level entities in any given universe, if all things in that universe are either those simple low-level entities or high-level things that are nothing more than aggregates of the low-level entities, and all of the behaviors and properties of the high-level entities fall out as inevitable consequences of the behaviors and properties of the low-level entities, then free will (at least as something possessed by the high-level entities) is an incoherent concept.
The claim of free will ultimately depends upon there being some kind of holism at work in the universe. Specifically, for free will to exist in me, it is necessary that I am an intrinsic, inherent individual (i.e. that seeing me as one single thing is not just some way of looking at the pile of matter that is generally considered me); that whatever Nature's principles of individuation are, I count as one of Nature's individuals; that I am a partless whole. Another way of saying this is that for free will to exist, some form of (very) strong emergence must be true. There may be more involved than this, but for there to be free will, this much at least must be true. For me to have free will, I must not be in the thrall of the functioning of my parts, no matter what the operating principles of those parts are, whether those parts function according to deterministic or indeterministic laws. My actions and my future state must depend on some qualitative essence of a holistic, indivisible me.
If the universe does, in fact exhibit the required type of holism, the principle of parsimony of natural laws must be discarded - we are stuck with an extremely baroque picture of the natural world. In such a world there would not just be a handful of fundamental things of which everything is made: photons, quarks, electrons, neutrinos, etc. and a relatively small number of laws that describe the interactions of this handful of fundamental things. We would instead have an infinite number of fundamental entities, these entities would be complicated, high-level seeming sorts of things, they might be transient, and each would have its own set of laws.
This lack of parsimony does not make such a scenario inconsistent or obviously incorrect, however. Imagine that something with free will is an entity whose behavior springs from its own particular nature, such that it generates, manifests, and in fact is its own law, the law of nature that applies only to it. It is an entirely novel thing in the universe, like a new elementary particle. What it does from instant to instant is a surprise to everything else in the universe, including the universe itself. Its behavior, after the fact, could be considered a new law of nature, if one insisted on clinging to that terminology. Furthermore, once the moment is gone, its law will never apply to anything else. In this scenario, the terminology of "things" "obeying" "laws" breaks down and becomes meaningless. If I act the way I do because of the inherent nature of the thing that I am, and what I am will never be repeated, one could say I obey my own custom-made law of nature, of which I am the only instantiation at a particular moment. Or one could not.
This is really just the degenerate case of any law of nature, in that all such laws are inductively derived. There is a sort of Platonism hiding in the concept of a law of nature. In real life there is no such thing. No electron in the history of the universe has ever obeyed a law. Balls on ramps and electrons do what they do not because of some law that they all know about, but because that's what they do. Each electron, without reference to any other electron, and without reference to the way it is supposed to behave, acts like an electron. Each one has somehow memorized, or "knows" its patterns of behavior. Its behavior is built into each electron individually. The law, such as it is, must be written into the hardwiring of each electron, copied a hundred zillion zillion times over, for as many electrons as there are in the universe. No one is obeying anything. As it turns out, all electrons behave pretty much the same way (for unknown reasons), so we write down a general characterization of that behavior and call it a law, and from then on we can speak as if all the electrons in the universe "obey the law".
A law of physics is something we invented, an abstraction, a convenient fiction to help us track the behavior we observe after many trials. Indeed, the whole terminology of "laws of nature" or "laws of physics" strikes me as an Enlightenment-era metaphor with a bit of cultural baggage attached to it, one that we have accepted into our ways of talking and thinking. It reminds me of the Victorian Rudyard Kiplingesque statement that the lion is the "king of the beasts". I can see why a someone of a certain era might phrase it that way, transposing a familiar hierarchical political order onto the natural world, in which no one preys upon a lion, but that's not really the way ecosystems work. Calling a lion the king of the beasts, like calling electron behavior a law of nature, says more about the mindset of the speaker than it does about lions or electrons.
What about any "laws" that apply to unique, high-level individuals? If we only have one data point, and always will only have that one data point, it really becomes a matter of preference as to whether to call the behavior of such an individual a law or random behavior. Any unique one-off "laws" that apply to the high-level entities would necessarily be forever unknowable to any outside observer. Looking at such an entity from the outside, its behavior would have to appear to have a random factor in it. Any system of laws applying to a universe with such things in it would characterize the regularities of the simple, low-level things as well as it could, and simply throw up its hands when it ran into the behavior of the high-level entities, labeling it as "random".
We would have a sort of dualism then, but it would be an epistemological dualism, not an ontological dualism. There would be only one universe with one kind of stuff in it, but there would be a division between that which we could characterize completely in third-person terms, and that which would be forever closed off to our laws and theories. In short, in such a picture of the world, given the characterizations a) I act randomly, b) I act out of free will, an expression of my inherent nature, or c) I act deterministically, obeying my unique law, it is perfectly valid and consistent to say d) all of the above.
In practical terms, if our world is really like this, it is unlikely that we could model my behavior with a machine, because the "laws" that determine my operation are unique to me at each instant (the "me" at each instant being different, each with its own law(s)), and undiscoverable without being me. And even if, by some chance, a machine could model my behavior perfectly for a time, say ten hours, there would be, in principle, no way to be sure that it would continue to do so for even one second more.
Oddly, such a view is actually a form of physicalism, in that it posits a physical basis for consciousness and free will, although one that is quite different from that which most physicalists suppose is true. Even if there are these high-level fundamental entities with their own one-off laws, there are still low-level entities like electrons and photons and their more generally applicable laws. Any claims we could make about the high-level entities and the ways in which they behave must not violate the more commonly known basic physical laws that describe the behavior of the low-level entities. Given that whenever we look at the world, all we see is the low-level entities, and their behavior seems pretty unmysteriously described by the physical laws that apply to such entities, is there any wiggle room for these purported unique high-level entities to do anything? Where are they hiding? This is another version of classic physicalist's challenge regarding the causal closure of the physical world: the dynamics of the world and everything in it are completely nailed down once we nail down the dynamics of the low-level stuff (the physics). However, this is not as true as it appears.
As it turns out, modern physics does characterize the behavior of the fundamental constituents of matter in the way I have said a free will-supporting universe would have to work: we know roughly how things will behave, but there is always an irreducible random factor. Quantum mechanics tells us that the low-level entities are governed by statistical laws only. The exact behavior of the low-level entities is thus not exhaustively and unmysteriously governed by laws - there is an irreducible "random" factor. There is, therefore, some wiggle room for consciousness (or, if you prefer, qualitative high-level physical entities) to be causally efficacious, to exert some extra influence on material things in the universe without violating any known laws. In effect, consciousness exhibiting free will would be a "hidden variable" in a correct physical theory, according to this hypothesis. Crucially, quantum mechanics also gives us examples in the real world of these indeterminate entities scaling upward from the level of the single subatomic particle in the form of entanglements, mixtures, and condensates.
We already have truly qualitative consciousness, and this consciousness constitutes a big, complex, indivisible whole. Moreover, this consciousness is efficacious. If you buy all of this, is there any room for there not to be a robust, libertarian free will in our world? But what can we say about how to individuate whatever it is that has it?
Let us imagine that the consciousness that has free will is a short term thing, more of a moment of consciousness rather than a constant, cradle-to-grave kind of consciousness (see Strawson 1997 for a good article about why this is a plausible, and perhaps the most plausible, way to talk about the self, or his longer work (2009)). We should also be careful about any assumptions about the number of consciousnesses that comprise me, in addition to how many there are across time. It may turn out that "me" is made of a conglomeration of lots of consciousnesses or moments of consciousness. There could be a fundamental sense in which consciousness is real, and possesses free will, and nevertheless the persistent unified self is a useful fiction, at least as we conceive it.
Besides the number and longevity of any freely willing entities that comprise an agent, there is a question about the boundaries between it and everything else. Free will is creative, even self-creative, but it is not just riffing in a vacuum. Somehow, we are aware of things. That is, some stuff from the world, over which we have no control, imposes itself upon us. So external stuff changes an agent's internal state, but in a way that the agent nevertheless exercises creative control over. Neither is it the case that the missing ingredient is a complete specification of the agent's ever-changing internal state. If that were the case, then the input from the outside world, together with the internal state, would dictate the agent's output and next internal state in the manner of the classic Finite State Machine of computer science, and we would be back to bare-bones functionalism.
A willful agent would have to incorporate external information into itself as part of its internal field of perception, but could stand back from it as it were, and regard it. Only in the context of free will does descriptive information (as opposed to prescriptive information) make sense. Central to the intuitions we have about free will is the claim that an agent gets to survey reality, then decide what it wants to do about it. It gets to be an unmoved mover, an uncaused cause. It gets to be aware of things without that awareness constituting an algorithm that it must execute. Free will is built into the concept of descriptive information and vice versa.
But does the idea of purely descriptive (i.e. non-prescriptive, non-algorithmic) information make sense? Doesn't the outside world, through physical causation, stick its fingers into you, and play you like a piano? To the extent that you are aware of it, it has pressed itself upon you, it has forced you to conform to it. Under pain of the infinite regress of the homunculus, you are not separate from your thoughts and percepts. As William James said, the thoughts are the thinkers. How can I be all one thing, shaped by reality, but also stand apart from my (descriptive) percepts as a detached observer? What does it mean to be aware of things, if I just am that awareness?
Free will is creative above all if it is anything. It doesn't have to be about anything, in particular, it doesn't have to be about the outside world. Remember, we are not talking (just) about picking options off a menu, even a very complex one, but about creating options in the first place. The "direct" percepts from the senses (I wish there were scare quotes even scarier than normal scare quotes, maybe ""direct"" percepts) don't constitute fingers playing us so much as they are elements that we might (or maybe should) incorporate somewhere in our created-moment-to-moment conscious field.
However short or long lived, however many there are between my ears, there is something in me that is all one consciousness, with some regions of it more malleable than others. The stiffer areas that we take to represent "raw sense data" are pretty undeniable. At the same time, and as part of that same moment of consciousness, there are other aspects that are free to play, to interpret, to want, to focus on this or that. External physical reality presses upon us so that parts of us assume a certain shape. Free will is the process by which I choose the next shape to assume. I can be influenced by a past state without being completely determined by it.
Free will exists if we broaden our notion of it to mean the qualitative, unitary creations of an all-at-once consciousness. But if we think of it as a detached observer deciding what to do about stuff it "knows", then free will is a useful fiction. The self that stands apart from the percepts is a construct, a simulation. The rest of the conscious field (the non-self) is descriptive information, stuff the simulated self "knows" or "perceives". We are subject to the User Illusion (see Nørretranders (1998)). We construct the self as part of the whole picture and attribute will to it. We are self-aware, but the self of which we are aware is a simulation. The whole has free will, but the simulated self only thinks it does.