 While the debate continues over whether the compatibilist or incompatibilist position better captures folk moral judgments of agents in deterministic universes, a related line of research has sprung up around what is widely taken to be the most convincing contemporary form of argument for incompatibilism: manipulation arguments (e.g., Mele 2006, 2013, Pereboom 2001, 2014). Pereboom’s Four-Case version, for example, begins with the case of an agent named Plum who is manipulated by neuroscientists who use a radio-like technology to change Plum’s neural states, which results in him wanting and then deciding to kill a man named White. In this case, it seems clear that Plum did not freely decide to kill White. Compare this case to a second one, in which the team of neuroscientists programmed Plum at the beginning of his life in a way that resulted in him developing the desire (and making the decision) to kill White. The incompatibilist argues that these two cases do not differ in a way that is relevant for whether Plum acted freely, and so, once again, it seems that Plum did not freely decide to kill White. Now compare this to a third case, in which Plum’s desire and decision to kill White were instead determined by his cultural and social milieu, rather than by a team of neuroscientists. Since the only difference between the second and third case is the particular technological process through which Plum’s mental states were determined, he would again seem to not have freely decided to kill White. Finally, in a fourth and final case, Plum’s desire and decision to kill White was determined jointly by the past states and the laws of nature in our own deterministic universe. Regarding these four cases, Pereboom argues that, since there is no difference between any of the four cases that is relevant to free will, if Plum was not morally responsible in the first case, then he was not morally responsible in the fourth.