Thus, on a standard reading of Book II, the prescriptive content of moral claims, along with their necessity and universality, led Kant to believe we know moral truths only a priori. However, some interpret Kant as saying that if a moral truth is a priori, then it must also be necessary and universal (Dancy 2007: 45). On this interpretation, if one knows P a priori, then P must be necessary; after all, it’s unclear how one could know a contingent truth without experience. Moreover, if P is neces