Abstract

In January 1641 Marin Mersenne forwarded to René Descartes a set of objections to the latter’s Meditations that Mersenne had solicited from “an Englishman.” This, along with some optical papers that Descartes may not have known were from the same person, was apparently his first philosophical encounter with Thomas Hobbes. The surviving correspondence and the Meditations’s third set of “Objections and Replies” show that the antipathy between these two otherwise excellent minds was virtually instantaneous. The irony has often been remarked that these men, who were both engaged in constructing a system of mechanical science and whose views were so similar on many major issues, should have become such bitter opponents.