In the Introduction to this book I claimed that an analysis of Hobbes's argument is not only worthwhile for its own sake but also useful as a tool for understanding the structure and justificatory force of what I call a “traditional” social contract argument, that is, one purporting to justify the state (of a certain sort). In this chapter, I want to make good on that claim, first, by exploring what structure this kind of argument must have, such that it can be valid and plausible, and, second, by showing how an argument with this structure actually works as a justification of the state. I will not apply in any detailed way this analysis of the social contract's justificatory force to specific arguments given by members of this tradition, but I will at least attempt a sketch of that application for certain of its major members.