The article systematically explores the compatibility of Hume's political philosophy and contractarianism by reconstructing Hume's criticism of the idea of a social contract. In a nutshell, the dispute concerns the theoretical reconstruction of the establishment and maintenance of normative institutions by individual behavior. At the center of the ... dispute are questions concerning the philosophical analysis of the normative force of obligatory norms, and the theoretical reconstruction of individual persons' reasons--or motives--for following them. The main part of the article is dedicated to the reconstruction of the philosophical motivations behind the different positions. I will contrast contractarian idealism as a theoretical approach for the study of normative phenomena with Hume's empiricist approach. I will also spell out the metaethical differences between the idea of a hypothetical contract and Hume's rule-consequentialist reconstruction of the source of social and political obligations. Returning to the question of whether one can be both a contractarian and a Humean, the different implications of the two approaches for the theoretical understanding of normative rule-following will be presented. The conclusion is that one cannot be both a contractarian and a Humean. The article ends with a defense of the foregoing analysis against two objections.