Critics often charge that agent-causal libertarianism is unintelligible due to the uniqueness of agent-causation—the sui generis causal relationship said to be involved when agents make free choices. This paper presents five objections, which are taken to be the only good objections, to agent-causal libertarianism and argues they all fail to show agent-causal libertarianism is unintelligible. The first four objections fail outright. The fifth objection fails in a special way. Naturalistic agent-causal libertarian theories succumb to this fifth objection; theistic agent-causal libertarian (...) theories do not. This entails that if agent-causal libertarianism is intelligible, then it is only so within theism. (shrink)