In 1960, the late Murray Rothbard wrote an article where he dissented from his mentor Ludwig von Mises in the realm of ethics, and says that libertarianism must be grounded in ethical absolutism rather than relativism:
I think it important to delineate briefly what relativism is and what the issues are on this important topic. Let us first consider the polar opposite of relativism: absolutism. The absolutist believes that man's mind, employing reason (which according to some absolutists is divinely inspired, according to others is given by nature), is capable of discovering and knowing truth: including the truth about reality, and the truth about what is best for man and best for himself as an individual.
The relativist denies this, denies that man's reason is capable of knowing truth, and does so by claiming that rather than being absolute, truth is relative to something else. This something else may be different things, and so there can be many kinds of relativist; some of these things have been the subject of psychology of each individual, the economic interests of the individual (or of the "class" to which he belongs), the "Spirit of the Age" in which the person happens to live, the social structure of the society in which he lives, his "culture," his race, etc. Philosophically, I believe that libertarianism — and the wider creed of sound individualism of which libertarianism is a part — must rest on absolutism and deny relativism.
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