Free Will, Determinism, and Moral Responsibility

The first half of this thesis is a survey of the PSR, followed by consideration of arguments for and against the principle. This survey spans from the Ancient Greeks to the present day, and gives the reader a sense of the ways in which the PSR has been used both implicitly and explicitly throughout the history of philosophy. I argue that, while none of the arguments either for or against the PSR provide conclusive evidence of its truth or falsity, we should adopt a presumption in its favour. The best hope the PSR sceptic has of demonstrating the PSR’s falsity would be to find empirical evidence of something non-deterministic, since the PSR entails determinism. The theory of libertarianism is considered as just such a counterexample; but I argue the evidence for libertarianism is flimsy, and so the presumption in favour of the PSR remains. The second half starts from the premise that the PSR—and hence also determinism—is true, and goes on to examine what implications this has for our moral responsibility practices. We examine incompatibilist arguments by van Inwagen and Galen Strawson, both of which appeal to the origination condition. I contend that these arguments are compelling precisely because the origination condition to which they appeal is compelling. This leaves us with a dilemma: it seems like we can either accept these incompatibilist arguments, which would require us to abandon our moral responsibility practices; or we could save our moral responsibility practices by adopting some form of compatibilism, but at the cost of denying the intuitively appealing origination condition. In fact, to avoid the costs of each horn of this dilemma, we can seek to create a ‘mixed view’ instead. We consider Vargas’s revisionism, Double’s free will subjectivism, and Smilansky’s illusionism and fundamental dualism, which help to shape the mixed view I argue for here: a consequentialist compatibilist theory of moral responsibility. This theory allows us to acknowledge the impossibility of true desert without dispensing with our responsibility practices.