Abstract

In the history of philosophy, Jacques Rohault and Pierre-Sylvain Régis bear a twofold burden. They are professed followers, epigones. Worse yet, the natural philosophy they teach has been consigned to the Tartarus of fable: not a theory that failed, but something that failed even to be a theory. In the years in which they were turning Cartesianism into a system, Newton and Huygens were preparing its demise. Its empirical claims were refuted, its mathematics was rendered obsolete by the calculus, its vortices and channelled magnetic particles met with the same rough justice Descartes meted out to Scholastic forms and qualities. Canonical history has little use for such figures. It prefers originals. Yet if ideas and arguments are not to seem to pass magically from one great mind to the next, we must have some account of the channels through which what was once novel and unique sediments into cliché and common ground. Those channels are not without bias and noise. Inevitably, currents from different streams meet and mix more or less coherently in the works of secondary figures, especially in the competitive intellectual world of the later seventeenth century, with its sometimes ferocious polemics fuelled by religious and political opposition. Cartesianism became a movement and—to use Leibniz’s word—a sect, divided within by disputes over the legacy of its founder, and facing opposition without from steadfast Aristotelians, pious theologians, and the avant garde of the new science. In Régis and Rohault Descartes’ legacy took the outward form of “system”. They present themselves as reworking Cartesian concepts and arguments into something coherent and comprehensive. Rohault, the more modest of the two, aims to reform the teaching of physics, still weighed down by the dead hand of Aristotle. He retains for the old philosophy only what is true and conjoin it with the new physics of Descartes, in whom France is no less fortunate than Greece once was in Aristotle (Rohault 1718, “Præfatio”)..