For many people, the idea of free will is bound up with the notion of “could have done otherwise”. By their lights, if only one future is possible for a person — that is, if the person cannot do otherwise — then free will is an illusion.
Philosopher Christian List — author of the recent book Why Free Will is Real — proposes an interesting species of free will based on the claim that while physics may be deterministic, behaviors at the agent level are not. Agents can do otherwise, according to List, and this is enough to ground free will even if physics is deterministic.
I think List is mistaken, but I’ll save my criticisms for the comment thread.
Readers can find List’s argument in this paper:
See you in the comment thread.