Hobbes, Descartes, and Ideas: A Secret Debate

The author proposes that the anonymous letter dated May 19, 1641, which Mersenne delivered to Descartes, should be attributed to Thomas Hobbes. Although the text is known, it is usually considered not so much in itself as for Descartes’s two replies, which contain important clarifications on the proof of God’s existence. Hobbes’ hand is revealed by various thematic, conceptual, and lexical analogies and, above all, by the presence of two doctrines characteristic of his thought: 1) the denial of the existence of intellectual ideas; 2) the assertion that the nature of God can only be described by the proposition “God exists”. Attribution to Hobbes of the May 19^th 1641 letter throws new light on the debate that followed Descartes’s Meditations as well as on Mersenne’s role.