 Philosophical analyses of rights have been dominated by two rival theories. One is the choice or will theory according to which to have a right is to possess a choice (e.g. Hart 1982; Steiner 1998). On that theory, rights can be possessed only by beings capable of choice. If we take the case of claim-rights (rights that impose corresponding duties upon others), those rights should be ascribed only to beings capable of exercising control over the performance of the corresponding duties. We can possess rights only if we are capable of exercising them.