of simplicity. Similarly, under the retributive theory, he contends that self-defense is appropriate even if the victim uses more force to defend themself. In particular, he proposes that the maximum amount of force that a potential victim can use is: And in this case H is the harm that the victim thinks that the other is going to inflict upon themself. However, if he uses more force than f(H), that additional force has to be subtracted later from the punishment that the felon gets. Animal rights and utilitarianism Nozick discusses in chapter 3 whether animals have rights too or whether they can be used, and if the species of the animal says anything about the extent to which this can be done. He also analyzes the proposal "utilitarianism for animals, Kantianism for people," ultimately rejecting it, saying: "Even for animals, utilitarianism won't do as the whole story, but the thicket of questions daunts us." Here Nozick also espouses ethical vegetarianism, saying: "Though I should say in my view the extra benefits Americans today can gain from eating animals do not justify doing it. So we shouldn't." Philosopher Josh Milburn has argued that Nozick's contributions have been overlooked in the literature on both animal ethics and libertarianism. Reception Anarchy, State, and Utopia came out of a semester-long course that Nozick taught with Michael Walzer at Harvard in 1971, called Capitalism and Socialism. The course was a debate between the two; Nozick's side is in Anarchy, State, and Utopia, and Walzer's side is in his Spheres of Justice (1983), in which he argues for "complex equality". Murray Rothbard, an anarcho-capitalist, criticizes Anarchy, State, and Utopia in his essay "Robert Nozick and the Immaculate Conception of the State" on the basis that: No existing state has actually developed by the 'invisible hand' process described by Nozick, and therefore Nozick, on his own grounds, should "advocate anarchism" and then "wait for his State to develop". Even if any State had been so conceived, individual rights are inalienable and therefore no existing State could be justified. A correct theory of contracts is the title-transfer theory which states that the only valid and enforceable contract is one that surrenders what is, in fact, philosophically alienable, and that only specific titles to property are so alienable. Therefore no one can surrender his own will, his body, other persons, or the rights of his posterity. The risk and