The libertarian goals—including immediate abolition of invasions of liberty—are “realistic” in the sense that they could be achieved if enough people agreed on them, and that, if achieved, the resulting libertarian system would be viable. The goal of immediate liberty is not unrealistic or “Utopian” because—in contrast to such goals as the “elimination of poverty”—its achievement is entirely dependent on man’s will. If, for example, everyone suddenly and immediately agreed on the overriding desirability of liberty, then total liberty would be immediately achieved.

Murray Rothbard, The Ethics of Liberty, Atlantic Highlands, New Jersey, 1982