<blockquote>"Although Rothbard usually found himself in close agreement with Mises, in one area he maintained that Mises was mistaken. Mises contended that ethical judgments were subjective: ultimate ends are not subject to rational assessment. Rothbard dissented, maintaining that an objective ethics could be founded on the requirements of human nature. His approach, based on his study of Aristotelian and Thomist philosophy, is presented in his major work
The Ethics of Liberty (1982), his major study of political philosophy.
In his system of political ethics, self-ownership is the basic principle. Given a robust conception of self-ownership, a compulsory government monopoly of protective services is illegitimate; and Rothbard endeavors to refute the arguments to the contrary of supporters of a minimal state, Robert Nozick chief among them. He contributes important clarifications to problems of libertarian legal theory, such as the nature of contracts and the appropriate standard of punishment. He explains why Mises’s instrumental argument for the market does not fully succeed, though he finds much of value in it; and he criticizes in careful detail Hayek’s view of the rule of law.
Rothbard modified the famous dictum of Marx: he wished both to understand and change the world. He endeavored to apply the ideas he had developed in his theoretical work to current politics and to bring libertarian views to the attention of the general public. One issue for him stood foremost. Like Randolph Bourne, he maintained that “war is the health of the state”; he accordingly opposed an aggressive foreign policy."
- David Gordon,
Murray N. Rothbard (1926-1995)</blockquote>