 What is it for someone to have a right? Here there are two competing theories whose respective virtues and vices have been extensively debated. In one camp is the will or choice theory (Hart 1973; Sumner 1987; Steiner 1994); inthe opposing camp is the welfare or interest theory (MacCormick 1982; Raz 1984; Kramer 1998). The first theory sees a right as the protected exercise of choice. In particular to have a right is to have the power to enforce or waive the duty of which the right is the correlative. The second theory sees a right as the protection of an interest of sufficient importance to impose on others certain duties whose discharge allows the right-holder to enjoy the interest in question. It is natural to think that each theory is more appropriate for certain kinds of rights. The will theory fits rights actively to do things (to speak, to associate with others) whereas the interest theory fits rights passively to enjoy or not to suffer things (to receive health care, not to be tortured). However the distinction between the theories of what it is to have a right is not the distinction between different kinds of rights, even if there are important relations between the two distinctions.