Letter to Simon Foucher with Notes on Foucher’s Reply to Des Gabets

Abstract

Leibniz’s intellectual achievements during the four years he spent in Paris, from March, 1672, to September, 1676¹, cannot be fully appraised until his papers from that period are completely published. The general impression that he forsook philosophy for mathematics is wrong; indeed, it contradicts his whole conception of the relation between the two fields. While his mathematical studies were advancing under the guidance of Huygens and by the reading of Pascal and Descartes, his philosophical conceptions were also being subjected to new tests and problems, for it is in this period that Malebranche produced the Recherche de la vérité and that Leibniz had opportunity for discussions with him, with Arnauld, with Foucher, and with other intellectual leaders. Now, too, he undertook a careful study of Descartes and Plato, whose Phaedo and Theaetetus he paraphrased during this period.

Simon Foucher, canon of Dijon (1644–97), had written a criticism of Malebranche’s work in 1675 from the point of view of the ancient Academy; in the following year he replied to a defense of that author by Dom Robert des Gabets. Leibniz’s letter to Foucher in 1675 concerns questions of subjectivism and our knowledge of the external world. His notes to Foucher’s reply to Dom Robert show that his own doctrine of ideas is now related explicitly to the problems of epistemology and logic.