I argue that obligations of an important type inhere in what I call 'joint commitments'. I propose a joint commitment account of everyday agreements. This could explain why some philosophers believe that we know of the obligating nature of agreements a priori. I compare and contrast obligations of joint commitment with obligations in the relatively narrow sense recommended by H. L. A. Hart, a recommendation that has been influential. Some central contexts in which Hart takes there to be obligations in (...) his sense are contexts in which there are obligations of joint commitment. Nonetheless, different senses of 'obligation' appear to be at issue. (shrink)

What is a social rule? This paper first notes three important problems for H.L.A. Hart's famous answer in the Concept of Law. An alternative account that avoids the problems is then sketched. It is less individualistic than Hart's and related accounts. This alternative account can explain a phenomenon observed but downplayed by Hart: the parties to a social rule feel that they are in some sense 'bound' to conform to it.