Two public intellectuals, psychologist Steven Pinker
and physicist Michio Kaku
have taken two minutes each of bigthink
time to tell you that you don’t need to worry about free will
denials. Pinker comes out of the gate as a materialist, saying that there is no metaphysical free will, no ghost in the machine. Everything psychological comes from the electrical activity of the wet brain
. But that brain is very complicated indeed. It comprises billions of neurons and trillions of synapses. Because of this complexity, many of its activities are not predictable by machines that have less computing power than the brain itself does. To Pinker, behavior (the will) is free if the brain activity that produces the behavior is too complex to be scientifically described. This definition sets the stage for freedom as an ever-shrinking domain. It is a negative definition of freedom in the sense that the more we learn about how the brain works, the less freedom we can claim. This pathetic retreat would not occur if freedom were not defined as that which we do not yet understand.
After defining free will in terms of ignorance, Pinker suggests that freely willed behavior is voluntary behavior. Voluntary behavior involves many brain regions because it requires the integration of lots of information. Should I make lasagna or fish for dinner? I choose lasagna because I am allergic to fish. Pinker explains that reasoned decisions are fundamentally different from reflexive behavior, and this is true. Reasoned decisions use more information and take more time than behavioral reflexes. In other words, reasoned decisions are more complicated and perhaps not as predictable. In that way, Pinker’s second argument reduces to his first. To say that the distinction between free and reflexive behavior is useful does not get us closer to the truth. Some things are useful and others are useless; some things are true and others are false. To equate the useful with the true is the pragmatic fallacy. Incidentally, Pinker does not explain why it is useful to call reason-based action freely willed. Why is this labeling more useful than simply calling these actions voluntary? ‘Voluntary’ means ‘willed.’ To insist on the label ‘freely willed’ is to raise the question of how ‘voluntary’ differs from ‘freely voluntary.’
Kaku knocks Newtonian determinism (the universe as a clockwork) with Heisenberg’s uncertainty principle. Einstein, who like Newton was a determinist, takes a beating along the way. Determinism is not true because electrons, and presumably other sub-atomic particles, refuse to be pinned down. Their location and behavior is contingent on observation, but not determined by it. It shows irreducible uncertainty and thus indeterminism. All this is familiar stuff, and so are the irrational innuendos and generalizations that come along with it. The biggest innuendo is that if there’s indeterminacy sub-atomically, then there’s indeterminacy supra-atomically. Kaku seems to suggest as much. But for all we know, it isn’t so. The kind of indeterminacy seen sub-atomically disappears at the level of atoms, molecules and large objects. If it weren’t so, we should see shape-shifters or cats that are both dead and alive until someone looks. But we don’t see such things, which was Schrödinger’s point. If the will arises from atomic-molecular brain activity, it cannot claim the electron’s freedom to hop about without cause.
I find it interesting to contemplate the idea that Pinker’s and Kaku’s argument will sound equally convincing to those who want to believe in free will. I wish they noticed that Pinker and Kaku look for support in opposite places. Whereas Pinker appeals to the macroscopic world of large, diverse, and interconnected brain systems, Kaku puts his hope in the microscopic world of electrons. So which is it? Or is the will free to be free in more than one way?
Reverse inferences are invalid.
 We can agree that "If there is free will, then there are limits to what we can explain scientifically." We do know that there are things we cannot explain (e.g., because they come out of complex systems like the brain). It does not follow that there is free will.
 Suppose we agree that "If free will is true, then it is also useful." Even so, we cannot conclude that free will is true because we know it to be useful (the pragmatic fallacy).
 Perhaps we agree that "If there is free will, then determinism is false." We cannot conclude, however, that there is free will because quantum mechanics has refuted strict determinism.
 Knowing that "If P, then Q," we can infer Q from P by modus ponens, but we cannot infer P from Q. This is the logical fallacy of affirming the consequent.
Pop quiz (check one):
[A] Pinker is a compatibilist and Kaku is not.
[B] The reverse of [A] is true.
[C] Both are compatibilists.
[D] What is a compatibilist?