 To begin with, scepticism about political obligation flows from the special features of legal authority, in particular, its wide scope, its institutionalized character, and its moral fallibility. That is why the familiar principles by which we justify the authority of teachers, parents, doctors, or executors do not readily generalize to cover all laws. Most sceptical arguments are about over-reach. They do not deny that legal authority is often valuable, or that there is often content-dependent reason to do what law requires; they do not deny that some people have moral obligations to obey; they do not even deny that there are some laws that everyone has a moral obligation to obey. They deny only that the conscientious subject is bound to take the law at its word, that he must share the self-image of the state.