Libertarians hate coercion. To the extent that the anarcho-capitalist right justifies its worldview in moral terms, it is through an appeal to the obscenity of brute force. The problem with the welfare state, according to many libertarians, is not that it redistributes resources from rich to poor but that it accomplishes this by threatening wealthy tax dodgers with imprisonment. Individual liberty is sacrosanct, and just social policies are those that do not violate a person’s will through a threat of state aggression. The logical flaws of this “nonaggression principle” are myriad. But most spring from the libertarian’s insistence on applying...