Murray Rothbard, in a paper entitled “The Ethics of Liberty,” argued that the standard for moral goodness is set by man’s nature. Whatever fulfills the nature of a living thing is good, and whatever diminishes the nature of a living thing is bad. When the living thing in question is a human being and when we are speaking of chosen ends, then we are speaking of moral “goods” and “bads.” Rothbard, in almost all respects, endorsed a natural-law doctrine as the groundwork for rights.
David Osterfeld, in response to Rothbard, claimed that Rothbard had failed to show why the actions of a human being should be in accord with his nature. The axiological rule that human behavior should conform to the requirements and needs of human life did not have “scientific status.”