Anselm is the first philosopher to attempt a systematic analysis of libertarian freedom. Regarding grace, he embrace's the position that grace is necessary for salvation and unmerited, while preserving a role for human freedom that is not in the least Pelagian. This paper sketches the problems with Augustine's compatibilism and with Pelagianism, and shows how Anselm reconciles human choice with classical theism, which entails that God is the source of everything that has ontological status. The paper concludes with an argument that, although Anselm holds that God does not offer grace to everyone, he could and should have done so.