This dissertation is about legal and moral obligation. In response to the skeptic who questions a) whether there are any obligations at all and/or b) whether particular claims about obligations in particular situations are true, an argument will be advanced affirming the existence of certain societal obligations. These societal obligations are moral obligations and recognition of them is required for demonstrating the legitimacy of the exercise of power by legal institutions. The theories of obligation of H.A. Prichard and W.D. Ross will be criticized. These theories neglect certain dimensions of obligation and do not provide an adequate response to certain forms of skepticism about obligation. Cases in Anglo-American contract law will be p...