Jean-Jacques Rousseau introduces three conceptions of the general will: an implicit will of collectives, a declared will of assemblies, and a personal will toward the common good. Where his Discourse on Political Economy uses only the first conception, the Social Contract and its unpublished “Geneva Manuscript” turn to the second and third. I argue that Rousseau's mature account in the Social Contract grounds legitimacy on the capacity of citizens to declare their common good through deliberation and the exercise of private discernment. This finding helps resolve a long-standing interpretive impasse between “formal” and “transcendent” accounts of the general will and illumines the role of democratic sovereignty in the Social Contract.