Abstract

This article considers Henri Poincaré’s conventionalism in historical context by comparing his use of such terms as “convention” and “conventional” with Charles Renouvier’s. As Renouvier was very influential in late nineteenth-century France, this comparison can provide some insight into how the terms were understood at the time. Renouvier was a political philosopher as well as a philosopher of science. He drew an analogy between the conventions or social contracts that govern society at large and the conventions that governed communities of researchers in mathematics and the sciences. Both kinds of conventions were living contracts for Renouvier, subject to revision and change. What emerges from the comparison is an interpretation of Poincaré’s conventionalism that belies the view that it is a rigid, unbending philosophy holding back scientific progress. Rather, it is one according to which scientists come together to form a temporary consensus about particular starting points in order to make research into nature possible yet retain the liberty to try something new when the old set of assumptions no longer proves fruitful.