The problem of understanding what free will is, or even whether it exists, is an age old philosophical problem. A very prevalent position, which I believe to be incorrect, is that free will and determinism cannot coincide. It is often assumed that if the world is completely deterministic, then free will cannot exist and therefore must be an illusion. (Even if that were true, what's the difference between a genuine free will and an illusory free will?) Some people even go so far as to define free will as people's choices not being deterministic. But that is an extreme case of begging the question. And completely invalid, since it denies the validity of the philosophical question of whether what we mean by free will can coexist with determinism.

First let me state that I do believe in free will. The most important reason I believe in it is by introspection: I am aware of my ability to make (free) choices. My position is also that free will and determinism can coexist. I thank Rob van Glabbeek for clarifying this issue for me and convincing me of this position. That doesn't mean I believe the universe is deterministic. I don't know whether it is. According to most interpretations of quantum mechanics many events are random, while according to some all events are deterministic.

Physically it seems to me that the only alternative to determinism is randomness. Either every event can be predicted by the laws of physics (determinism) or some events cannot be fully predicted and are therefore partly random. Those who believe that free will cannot be explained under determinism, therefore necessarily have to believe that physical randomness must be the explanation for free will. Even though Bryan Caplan is one of the many who incorrectly assumes that free will cannot coincide with determinism, in his essay about free will he does explain quite well how randomness does not explain free will:

A further confusion identitifies free will with randomness, probabilism, and (of course) quantum mechanics. But I say that free will and randomness have nothing whatever to do with each other; indeed, a probabilistic theory of choice is just as contrary to the freedom of the will as a fully deterministic one. The argument here is extremely simple. Imagine that my action is determined by the roll of a six-sided die; if it comes up six, I raise my arm. Now suppose that all six faces have a six on them. Now it is clear that in this case I have no free will. But suppose we put six different faces on the die, each one determining a different action. Am I any freer than before? On te contrary, I am fully a puppet dangling from the proverbial strings. The point is simply that if my actions are determined by any outside process, then I am as fully unfree whether those processes are deterministic or have a random element in them. To uphold free will then, we must deny that either of these theories describes the etiology of the mind.

As said, I agree with Caplan's idea that randomness is not related to free will, though I disagree with his idea that a fully deterministic theory of choice is contrary to the freedom of will. Apart from the fact that it remains unclear what physical alternative there is to determinism and randomness, Caplan's mistake lies in his confusion between an inside and an outside deterministic process. I fully agree that if our choices are determined by any outside process, then we can have no free will. But I hope to explain in this article, that if we are determined by an inside process, in other words if we are the process rather than the process being external to us, we can have free will.

The wording of free will is a confusing one. What we mean by free will is really free choice. We are free to choose whatever we want. But whether or not we literally have free will is not so certain. We have many wants and needs and preferences that we cannot change simply by choosing to change them. In that sense, our will, or what we want, is in many cases fixed. If I like bananas, but don't like beans, I am free to choose to eat bananas, or even beans (if I think they are healthy I might eat them even if I don't like them). However, I do not have the ability to choose instantly that from now on I like beans and don't like bananas.

Fourth, try the following thought experiment. Our brilliant neurophysiologists come up with an equation that they claim will predict all of our behavior. The equation is so good that it even incorporates our reaction to the equation, our reaction to knowing that it incorporates our reaction, and so on indefinitely. Suppose that the equation says that the next thing that you will do is raise your arm. Do you seriously believe that you couldn't falsify this prediction by failing to raise your arm? But if you can falsify any prediction about your arm, and if the prediction is derived perfectly from a comprehensive knowledge of your body's constituent micro-particles, then your mind must be free.

Although, as said, I certainly agree with Caplan that we have free will, it is not something that follows from this experiment. Predicting something that in turn is partly based on that prediction itself, is simply an impossibility. That has nothing to do with free will or determinism, but is a matter of logic. This becomes clear if we replace the human in Caplan's example with a computer which will either turn on a red light or a green light. Suppose we study the computer program, which is completely deterministic. Based on that I make a prediction whether the computer will go green or red. I also feed that prediction as input into the computer. Now suppose the computer is programmed to go green or red so as to invalidate my prediction. If I predict green it will go red, and vice versa. Under those circumstances it is simply impossible for me to predict what the computer will do, even though it is deterministic. This does not prove the computer has free will, any more than Caplan's story proves people have free will. Caplan falsely assumes that the example demonstrates that people's behaviour cannot be based on deterministic laws. But as the example with the computer demonstrates, the computer is perfectly deterministic. Similarly the possibility remains that people are perfectly deterministic. Logically neither computers nor people can be predicted if they are allowed to take your prediction into account before they act. But under determinism both computers and people can still be predicted in theory, as long as you don't tell them your prediction.

I think the way we use the words "free will", it simply means that we have the option to choose between A and B. From introspection it seems obvious that we do in fact have this free will. As mentioned, free will does not seem to go along very well with randomness, since that would mean my choices, at least in part, are made at random instead of being determined by my preferences and personality. However, free will seems to go along just fine with determinism. The fact that what I will choose can be predicted in principle by the laws of physics does not mean I cannot choose freely. I will always choose what I think is best and what I think is best is determined by my values, personality and the information I have and therefore it can be expected to be predictable at every point. It would only not be predictable if I were to sometimes choose what I think is not best, which is impossible, since all beings act purposefully.

One can often predict what someone else will choose. If I want to cross the street and there's a car coming you can predict based on my personality and values that I will wait to cross the street until the car has passed by. That doesn't mean I am forced to make that choice. I make the choice voluntarily because it's the best choice for me, which is something you can know and therefore predict. It is precisely the fact that people are thinking beings that make rational decisions rather than random decisions that makes their choices predictable in principle. Even if people make what appear to be irrational decisions, they would be predictable in principle based on knowing that they decide rationally on the basis of certain incorrect ideas.

When people say that they are forced by the laws of physics to make certain choices, and thus they cannot have free will, they are confusing themselves with an external force. It may be true that the laws of physics operating in our brains determine our choices. But we are exactly that physical part of the universe which is our brain. And there is an equivalence between the laws of nature operating on our brain and ourselves. We are our brain plus the physical laws that operate on it. To say that we are forced by physical laws to make certain choices is nonsensical, since that amounts to saying we are forcing ourselves to make certain choices. The idea of force is only appropriate if something external, outside of our brain, forces us to make certain choices. Such as when we are forced to do something at gun point. But to say that we are forced by the fact that we are who we are just doesn't make sense.

A free will unconstrained by the laws of physics is in fact impossible, since everything that exists is constrained by the laws of physics. However, what that implies is not that we don't have free will, but that we are part of the physical universe rather than mystical spirits. The argument for free will is that all choices are logically possible, even though they may not all be physically possible. But physics does not constrain free will, rather your free will is part of the physical process. Your whole choice mechanism is part of physics. It is not appropriate to use the physics of free will as an argument against itself, just as, for example, it is not appropriate to apply the concept of time to itself and conclude that "time flows".

What about, say, an alarm clock going off at a certain time at which I set the alarm? Surely that is not an example of the alarm clock having free will, of choosing to go off at a certain time? I tend to think that if you look purely mechanically and physically there is only a difference in degree between say an alarm clock "choosing" to go off at its set time and a person making a choice. A human is incredibly complex while an alarm clock has a relatively simple "decision making" mechanism. With a computer, which is a bit more complicated than an alarm clock, indeed it is not that uncommon language use to say, when such and such happens the computer "chooses" to do this or that. But I think that we normally reserve the word choice for entities which are thought to be conscious. And because we assume that people are conscious and alarm clocks are not we say that people make choices while alarm clocks do not.

The fear of some is that once we admit that people's behaviour may be physically determined, they cease to be responsible for their actions. I disagree. The fact that you are who you are, namely part of a physical universe determined by deterministic laws, doesn't alter the fact that you do what you do. And that you have a choice to do A or B. Even if that choice is predictable in principle, it's still something you choose to do, and therefore you should be held accountable.

That aside, for legal purposes the question of whether people are guilty, accountable, at fault, responsible, for their own actions is largely irrelevant. It is always a good idea to punish criminals, in order to give a disincentive to criminal behaviour, regardless of whether the criminals are philosophically responsible.

Furthermore, it is true that if you murder someone that is "just" a characteristic of the universe. But is is more precise to say it is a characteristic of the small part of the universe that is you. And even though from the standpoint of physics it was determined you chose X, it was not a logical necessity for you to choose X. Therefore, we say that you are responsible.

Why then is a tree not responsible for falling on top of you? Well, there is no fundamental physical law that says that humans are responsible for their actions and trees are not. Responsibility is a human term describing how humans relate to each other, it is an emergent phenomenon which can only be understood by humans. We ascribe responsibility to humans because we consider humans conscious and choosing entities. Most people are angry at other people doing bad things but are not angry at trees falling over, that's just bad luck. On the other hand I guess there is no logical contradiction in viewing people as trees. There might be people who, when they are beaten and robbed, say: "Why should I be angry? Some people just are like that. Being angry at them would be just as silly as being angry at a rock for falling on top of me." But I'm not like that. I love people who do good things and I hate people who do bad things.

Whether or not are actions are determind from a physical standpoint, do we not still feel responsible for our actions? Is it then not reasonable to say that we do the things we do? Choose the things we do? Nobody is forcing us to do the things we do. Even if some people sometimes feel the inclination to act in certain ways seems come from a source outside of them, is that source not really part of them?

I think it is a misconception that because what I do is detemined mechanistically, from the perspective of an outsider, by the laws of physics operating on my brain, it therefore follows that I do not choose, or am forced to choose, and that I am not responsible for my actions. Consider who the "I" is in the statement: "I cannot help do X, for X is mechanistically determined by the operations of my brain". But I am the operations of my brain. So the statement really means "I cannot help do X, for X is mechanistically determined by I", which doesn't make sense. Free will precisely means that what I do is determined by who I am i.e. chosen by myself. I am exactly equal to that part of the universe which is my brain including the physical laws operating on it. When I do something, that act is the fault of that part of the multiverse. And that part of the multiverse is called I. So when I do something, it's my fault.

I am never forced to do anything, even if it is determined that I will always choose what I think is best. The idea that there is a separation, a dualism, where my spiritial I is forced by my material I (my deterministic brain operating under the laws of physics) is incoherent.

David Deutsch and others seem to argue that the Multiple World Interpretation of Quantum Mechanics, or MWI in short, is required to make free will possible. (The fact that I am considering this issue does not imply that I either agree or disagree with MWI.) According to them MWI gives meaning to the contingency required for there to be free will. The argument seems to be that if I do only one thing in one universe, then the fact that I could have done something else doesn't seem to have meaning. Since I do only one thing, and this one thing is determined, talk of free will seems meaningless. Because in MWI theory different copies of me actually do make diffent choices, free will has meaning. By doing your best to do something you increase the proportion of copies of you doing one thing instead of another. I don't agree with all this. I don't think whether MWI is true has any relevance for free will. I won't go into that further in this article, except to note I have already argued above how a single deterministic universe and free will can coincide, plus I will make one short point about MWI and free will.

For free will to continue under MWI one might sort of hope that the brain does not make different decisions based on internal quantum phenomena. That is, we would like any quantum interference in the brain to converge into one decision, just as in a classical or a quantum computer, because that would be in line with consistency of personality. One would hope that decisions we make only diverge according to different courses of action of the world outside of us. Even if all your copies do the same thing in a situation, you still have free will. In fact I would argue exactly the opposite as what some MWI proponents seem to imply. The more copies do the same thing in the same situation, the stronger your free will. If 50% of copies do one thing and 50% another, then your choice seems just random. The closer the number of copies doing something is to 100% the more what you do is determined by your personality and views i.e. free will instead of randomness.

Also see my article Free will and Newcomb's paradox. This provides some additional ideas and analysis of free will, in the context of solving Newcomb's paradox.

A Case for Free Will AND Determinism

Email: henry@sturman.net