The idea that society is a cooperative venture has been used by contractualists, contractarians, and deliberative democrats to justify the burdens of society to each member. In such a cooperative venture, those who benefit from society owe a contribution and those who contribute are owed benefits. Even though this idea is quite intuitive, there are deep disagreements about what makes society cooperative. Some focus on acts of production, others on fair interaction, and still others on the intention to contribute to (...) shared projects. In this article, I show where this kind of disagreement causes problems in current debates, and I defend one conception of social cooperation as uniquely best. Specifically, I argue that the relevant acts that make society a cooperative venture are acts of institutional rule-following. Society is a cooperative venture because people cooperate with one another by following the rules of our basic institutions. (shrink)