 Despite its powerful intuitive pull for some, many have argued that agent-causal libertarianism is obscure or even incoherent. The stock objection used to be that the very idea of agent-causation—causation by agents that is not reducible to causation by mental states and events involving the agent—is incoherent, but this objection has become less common due to pioneering work by Chisholm (1966, 1976), Taylor (1974), O’Connor (2000, 2011), Clarke (2003), and Steward 2012, ch. 8). More common objections now concern, first, how to understand the relationship between agent-causation and an agent’s reasons (or motivations in general), and, second, the empirical adequacy of agent-causal libertarianism. With respect to the first worry, it is widely assumed that the only (or at least best) way to understand reasons-explanation and motivational influence is within a causal account of reasons, where reasons cause our actions (Davidson 1963; Mele 1992). If agent-causal libertarians accept that self-determined actions, in addition to being agent-caused, must also be caused by agents’ reasons that favored those actions, then agent-causal libertarians need to explain how to integrate these causes (for a detailed attempt to do just this, see Clarke 2003, ch. 8). Given that these two causes seem distinct, is it not possible that the agent cause his decision to \(\phi\) and yet the agent’s reasons simultaneously cause an incompatible decision to \(\psi\)? If agent-causal libertarians side-step this difficult question by denying that reasons cause action, then they must explain how reasons can explain and motivate action without causing it; and this has turned out to be no easy task. (For more general attempts to understand reasons-explanation and motivation within a non-causal framework see Schueler 1995, 2003; Sehon 2005). For further discussion see the entry on  incompatibilist (nondeterministic) theories of free will.