The many-worlds theory of Hugh Everett may allow physicalists to believe in free will, as explained in my last blog post. Since every choice you do not make will create a parallel universe where a parallel you will make your discarded choice there is no conditioning logic that means that you as you will necessarily have to choose one given alternative. All possible alternatives are equally realistic and each choice possesses its own impeccable internal logic. You may be free to choose, but whatever choice you make will appear to be the inevitable result of your conditioning.
The problem with such a theory of free will is that it seems to assume that you subscribe to the many-world theory; a theory which it is hard to get one’s head around despite its respectability. Another interpretation of quantum mechanics might provide another route to the same result, however.
The firm assumption of quantum mechanics is that alternatives are preceded by a state of superposition. At that moment the alternative states, the cat is dead and the cat is not dead, coexist. One very popular theory of quantum mechanics assume that the wave function that sustains the co-existence of the two alternative states collapses, so that only one of the two states survives. Parallel universes do not arise. In fact, a number of sophisticated theories assume superposition but no ensuing parallel universes. Question is then whether the co-existence of alternative states in superposition is dissolved randomly or deliberately. Will your kissing someone or not be decided arbitrarily or will you be able to dissolve the preceding superposition (where you both kiss and don’t kiss) by deliberate, free choice? Both alternatives are equally possible, each choice will possess its own immaculate internal logic!
Free will theorists have heralded the indeterminism of quantum mechanics as a sign that free will may exist. But that is stopping half-way. The superposition of alternatives before choices are made, or parallel universes arise, poses the question whether we choose or whether all the choices we seem to make are, in fact, random. The contending theories are thus not free will versus mechanistic determination, but free will versus complete randomness. Resolving that contention, how could human experience be reconciled with the complete randomness of our choices?