 The idea that choice entails the ability to do otherwise has been taken by many philosophers to underwrite our practice of holding agents responsible for their choices. But understanding the precise meaning of the counterfactual could have claim in  (9)  requires navigating the classic problem of free will: if we live in a universe where the current state of the universe is determined (or near enough) by the prior state of the universe and the physical laws, then it seems like every action of every agent, including their “choices”, are predetermined. So interpreting this intuitively plausible counterfactual  (9)  leads quite quickly to a deep philosophical dilemma. One can maintain, with some Incompatibilists, that  (9)  is a false claim about what’s physically possible, and revisit the understanding of agency, choice, and responsibility above—the entry  incompatibilist theories of free will  explores this  further.[7]  Alternatively, one can maintain that  (9)  is a true claim about some non-physical sense of possibility, and explain how that is appropriate to our understanding of choice and responsibility—the entry  compatibilism  explores this further. It is wrong to construe debates about free will as just debates about the meaning of counterfactuals. But, the semantics of counterfactuals can have a substantive impact on delimiting the space of possible solutions, and perhaps even deciding between them. The same is true for research on counterfactual thinking in psychology.