published in Philosophy Now, January 1991

As the cognitive sciences have developed, it has seemed increasingly likely that our brains work along deterministic lines (or, if quantum effects are non-negligible, at the very least along mechanical lines). One of the standard philosophical debates regards whether we have free will in determining our actions, or whether our actions are determined by forces beyond our control; in response to the above developments, which express ideas which have become increasingly more refined and complex since the Enlightenment, the debate has arisen: are the concepts of determinism (or naturalism or materialism) logically compatible with free will? So some of the debate has shifted from between the "determinists" and the "anti-determinists" to between the "compatibilists" and the "anti-compatibilists".

Peter van Inwagen offers a standard anti-compatibilist argument; he is actually arguing for free will as opposed to against determinism, but his argument assumes that determinism is incompatible with free will, and that it is incompatible with moral responsibility. Since (he claims) we do in fact have moral responsibility, determinism is false. Hence, he concludes, we have free will.

Daniel Dennett would not fault the validity of van Inwagen's main argument; he does not agree with the truth of its premises. His approach is to reformulate the concept of "up to us" and "responsibility." Before I expend on that, however, I want to discuss what I think is the difference in the philosophers' starting points that caused the divergence off opinion.

Descartes viewed the mind as a pure ego: a permanent, spiritual substance untouched by physical processes. It could be influenced by them through the senses but there was no other manner in which it was influenced by the mechanistic events going on outside in the world. It could influence those events indirectly however through the manipulation of the host body (via the pineal gland).

As modern science advanced in its understanding of the way the brain works, this image of the mind was undermined. It began to look more and more as if the mind is a purely physical entity, as if there is no "person" or "pure ego" outside the realm of physical causation. Some philosophers (like the Churchlands) now go so far as to say that the mind does not exist at all. In the face of this, the metaphysician has two options: retrenchment and retreat.

Dennett's strategy of retrenchment is to build a second line of defense for the concept of free will, by reformulating the concept so that it is not in conflict with current theories in the brain sciences. There is a sacrifice in that he loses track of our ordinary, common-sense views of what mind and free will are. Dennett claims he is doing ordinary language philosophy, although adoption of his views seems to involve divergence from our ordinary-language conceptions.

Van Inwagen's strategy of retreat is to dismiss current trends in science and maintain a belief in a cartesian conception of "agent causation", that is, the view that people can cause things to happen in the world outside of the normal, mechanistic, physical causation. He complains that many philosophers are overawed by current science and make exaggerated assumptions about the degree to which it will eventually be able to explain how the brain (and the mind) works. However, for various reasons, among them being the lack of success of the "hidden variable" model of quantum physics, it is highly unlikely that such a complete explanation will ever come about. This would imply that the brain was not deterministic in the strictest sense of the term. Nevertheless, as van Inwagen correctly points out, even were determinism false there would still be no guarantee that we have free will. First, if our hopes turned on quantum effects being able to affect brain chemistry, it is still conceivable that they might turn out to be too small to be significant. Second, even if they did have an effect which was non-negligible we could still turn out to be strictly mechanical, and that does not seem to be the type of free will that van Inwagen wants, if he wants an "actor" making responsible decisions free from causal constraints (at least physical causal constraints, as he accepts psychological causation). Ultimately, van Inwagen states that we know we have free will because free will is entailed by moral responsibility, and we know that people are morally responsible for their actions. The rationale for this entailment is van Inwagen's conception of moral responsibility, which requires that a person could have done otherwise.

Yet Dennett claims (contrary to the view van Inwagen would want to attribute to him as a compatibilist) there are cases of responsible action when one could have done otherwise. That is the purpose of a moral education, to make one incapable of, say, torturing an innocent person in exchange for a thousand pounds. We may have been trained since childhood to consider such an offer unacceptable, yet most of us would not claim when we rejected the offer we were not doing so freely. Dennett asks, what is it we want to know of a person when we wonder, could he have done otherwise in a particular situation? Are we asking, given the exact brain states he had and the exact state of the universe as it was at the time of the act, could the person have done otherwise than he actually did in the non-counterfactual world? Dennett rejects this question as unanswerable, and even if answerable as unhelpful in determining responsibility. Unanswerable because it is impossible for us to duplicate a model of such complexity; unhelpful because even if we could by some stretch of the imagination lay out such a model, we will never naturally find ourselves in such a state -- even were the external conditions the same the cognitive conditions would not be. So we are left with the challenge of how to interpret the question so that it does illuminate. Dennett advocates that we interpret "could he have done otherwise?" as "was the action consistent with a model of his character in which it would have psychologically consistent for him to have done otherwise?" Thus he argues that we would still hold people morally responsible whether we accepted van Inwagen's concept of free will or not, because the consideration we have in mind whether we ask whether someone "could have done otherwise" are irrelevant to issues of free will and determinism.

I doubt van Inwagen would be satisfied with Dennett's approach. Despite its ingenuity it comes off like a verbal trick; it "solves the problem" but at the cost of not really approaching what we worry about when we worry whether we have free will, or responsibility. Of course, Dennett would respond that these worries are bugbears. One might question my accusation of verbal trickery applied to Dennett: when has the making of a distinction, which (if correct) would invalidate an influential argument that overlooks it, been dismissable as a trick?

Most philosophers writing on the subject do so in an attempt to show that we have free will; the anti-free will group is small if it exists at all. However, as the cognitive sciences have developed a new factor has been added to the discussion, and that is whether we have a variety of free will worth wanting, to hark back to the subtitle of Dennett's book. Suppose I defined "having free will" to mean "the property of being a featherless biped with teeth"; this is a bit silly (and a questionable etymology) but we would certainly have free will under such a definition. Is this worth wanting? A great deal of philosophical work has been done over the centuries with a certain conception of free will, and it is that conception which van Inwagen writes about and which, I think, fits our everyday use of the expression. Van Inwagen would probably not consider Dennett's version of free will "worth wanting" and we may not want to either, if we want to hold to our everyday use. Thus, if we took that view, Dennett's formulation would seem to be mere word-play, just as my featherless biped formulation was.

That, I think, is a manifestation of the fundamental disagreement. Resolving this disagreement would help resolve the issue between them about free will, but I have my doubts over whether any such resolution is possible. Their disagreement is based on a fundamental judgement the two have made about how philosophy should respond to the other disciplines around it.

I agree with van Inwagen's observation that, given the current state of science, it is premature to claim that determinism (neurologically if not cosmologically) is true; however, it is certainly premature to claim that it is false as well. I see no reason to be convinced by van Inwagen's arguments unless he is able to give some vague picture of how he thinks agent causation might physically work. I don't expect it to be exact, but he ought to at least be able to tell a convincing story. The compatibilist can tell a very interesting story, though we might not care so much for their conclusions. Without some kind of workable story, so far as I can tell, van Inwagen is tacitly accepting Cartesian egos as the source of free will. He is well aware of this shortcoming but is not overly bothered by it. I think that falling back on the Cartesian model and trying to operate outside the realm of empirical science is not a sacrifice worth making. Dennett's recommendations are worth taking seriously, despite his apparent lack of awareness of the sacrifice he makes in abandoning our ordinary concept of free will -- I think this is a sacrifice worth making.