The distribution of moral properties supervenes on the distribution of natural properties, and this provides a puzzle for non-naturalism: what could explain supervenience if moral properties are not natural properties? Enoch claims moral principles explain supervenience. But this solution is incomplete without an account of what moral principles and properties are, and what relation holds between them. This paper begins to develop such an account by exploring analogous issues for Realism about Laws of nature in philosophy of science. Appealing to Mumford’s Central Dilemma for Realism about Laws, I argue that for moral principles to explain supervenience, moral properties must be ontologically dependent on the principles. I suggest that moral properties are relations between moral principles and natural properties. I also explore what it would take to adapt this explanation to a pluralistic theory of morality. Contributory reasons avoid the Cartwright Problem for Laws in a way component forces cannot.