 Moreover, the sanction theory of rights has problems of its own. The sanction theory of rights treats the desirability of social enforcement as constitutive of the idea of a right. But this seems to get things backward. It is because we have rights that society ought to enforce them; it is not that we have rights to whatever society ought to enforce. The desirability of social enforcement seems consequential on the existence of the right. This is even clearer, because there are some claims that society ought to enforce that are not rights. Among the things that society ought to recognize and protect are both rights and privileges. The exact line between rights and privileges is not always clear. But we recognize the distinction in claiming that some interests and opportunities that the state ought to protect are not ones that can be claimed as a matter of right. This shows that the usefulness of social enforcement cannot be constitutive of a right, because otherwise privileges would be rights.