In Defense of the Four-Case Manipulation Argument for Hard Incompatibilism

Abstract

Derk Pereboom's four-case manipulation argument has proved to be a major point of contention between compatibilism and hard incompatibilism in the debate over causal determinism's alleged threat to free will and moral responsibility. Notably, the four-case argument has met Michael Mckenna's so called hard-line reply, a six-case argument modeled after Pereboom’s four-case one and intended to establish a dialectical stalemate between the compatibilist and incompatibilist positions on largely intuitive grounds. Mckenna contends that his six-case argument elicits compatibilistically friendly intuitions about Pereboom’s case 1 in which the agent is said to be morally responsible. I argue that Mckenna's hard-line reply does not succeed in demonstrating this alleged stalemate between the two debating sides. The current state of the dispute can be so characterized only if the opposing sides' reported intuitions enjoy evidential equivalence. But, I argue, the evidential credentials of these intuitions are not equivalent. The newly elicited intuition from Mckenna’s six-case argument cannot be assumed to do any evidential work without a good explanation of why it cannot be a commanding intuition. I argue that Mckenna's proposed explanation is not adequate as it stands. Finally, I offer a diagnosis of the origins of the apparent dialectical impasse, and, on this basis, seek to advance the debate on novel grounds. I defend the four-case argument by locating the disagreement between the two sides in the particular application of the generalization method.