his way out of this punishment could enter only as a voluntary contract with the plaintiff. Then, the concept of proportional punishment and retribution as a theory of punishment is discussed. Rothbard criticizes the view that retribution is a primitive and barbaric concept and points out the shortcomings of the modern theories of deterrence and rehabilitation. He argues that the deterrence principle implies punishments that most people would consider grossly unjust, while the rehabilitation principle leads to arbitrary and gross injustice and places enormous and arbitrary power to decide men’s fates in the hands of the dispensers of punishment. Rothbard suggests that proportional punishment is the only criterion for punishment that truly meets our conceptions of justice. Abortion and the rights of children Chapter 14, "Children and Rights", examines the question of children's rights, and contains some of Rothbard's most controversial views. Rothbard establishes that every person has the right to own their own body and any virgin land they find or transform by labor, and this leads to a structure of property rights in all goods, including those obtained by exchange or gift. However, Rothbard argues that the issue of children's rights is more difficult because they are not natural self-owners like adults. He starts by addressing the issue of abortion, and argues that a woman has the right to expel an unwanted fetus from her body, and any laws restricting or prohibiting abortion violate a woman's rights. Rothbard rejects the idea that a mother has contracted with the fetus by consenting to conception, and he argues that the fetus is a parasitic invader of the mother's body if she decides she does not want it there. He also dismisses the idea that the fetus is a human being with the right to life and points out that a born human does not have the right to be a coercive parasite within an unwilling human host. Rothbard concludes that the right to life is ambiguous, and any proper rights implied by advocates of the "right to life" are included in the concept of the right to self-ownership. Rothbard argues that the parental jurisdiction over children should end when the child demonstrates their full rights of self-ownership by leaving or "running away" from home, regardless of age. This means that "we must grant to every child the absolute right to runaway and to find new foster parents who will voluntarily