The term science sociale was first employed by Mirabeau père in 1767, not Emmanuel-Joseph Sieyès in 1789, as historians until now believed. Taking this discovery as its starting point, this article examines the ways in which the idea of a science of society was successively conceptualized in the late eighteenth century by Mirabeau, Sieyès, and Nicolas de Condorcet. Situating their ideas in the context of evolving discussions over the reform of the French state, it argues that they developed three different versions of social science, and that these reflected different attempts to answer the question of how to achieve collective prosperity, justice, and happiness under modern conditions. This article further highlights the changing modes of historical temporality that informed those approaches, which shifted from a focus on the social forms of a mythical past, to a concern with the prevailing norms of the present, to an emphasis, finally, on the likely developments of an ever-perfecting future. In doing so, it shows that the history of early French social science is best understood not as a process of gradual advancement, but rather as one of serial reinvention.