Saint Anselm of Canterbury (1033-1109) was the outstanding Christian philosopher and theologian of the eleventh century. He is best known for the celebrated “ontological argument” for the existence of God in chapter two of the Proslogion, but his contributions to philosophical theology (and indeed to philosophy more generally) go well beyond the ontological argument. In what follows I examine Anselm's theistic proofs, his conception of the divine nature, and his account of human freedom, sin, and redemption.