 Whether a priori or a posteriori, the arguments of the philosophical anarchists pose a serious challenge to those who believe in a general obligation to obey the law. This challenge is made especially difficult by the powerful objections that Simmons and other a posteriori anarchists have brought against the existing theories of political obligation. The most effective response, of course, would be to demonstrate that one’s favored theory does not succumb to these objections, and we shall briefly consider attempts to respond in this fashion in §4, below. Some general attempts to refute philosophical anarchism ought to be noted first, however.