Abstract This paper aims to defend deliberation-compatibilism against several objections, including a recent counterexample by Yishai Cohen that involves a deliberator who believes that whichever action she performs will be the result of deterministic manipulation. It begins by offering a Moorean-style proof of deliberation-compatibilism. It then turns to the leading argument for deliberation-incompatibilism, which is based on the presumed incompatibility of causal determinism and the ‘openness’ required for rational deliberation. The paper explains why this argument fails and develops a coherent account of how one can rationally deliberate and believe in causal determinism without inconsistency. The second half of the paper then takes up Cohen's proposed counterexample and his Four-Case Deliberation Argument (FCDA) against deliberation-compatibilism, which is meant to mirror Derk Pereboom's famous Four-Case Manipulation Argument. In response, the author defends a hard-line reply to FCDA but also argues that the notion of ‘sourcehood’ relevant to rational deliberation differs from that involved in free will.