Derk Pereboom and Gregg Caruso’s chapter on hard-incompatibilist existentialism explores the practical and existential implications of free will skepticism, focusing on punishment, morality, and meaning in life. They consider two different routes to free will skepticism: the route that denies the causal efficacy of the types of willing required for free will, which receives impetus from pioneering work in neuroscience, and the route that does not deny the causal efficacy of the will but instead claims that, whether deterministic or indeterministic, it does not achieve the level of control to count as free will. They argue that while there are compelling objections to the first route, the second remains intact and that free will skepticism allows for adequate ways of responding to criminal behavior—in particular, incapacitation, rehabilitation, and alternation of relevant social conditions—and that these methods are both morally justified and sufficient for good social policy.