Abstract
In this article I present some unpublished fragments concerning the life and works of René Descartes (1596–1650), gathered from the academic commentaries of Johannes de Raey (1620/1622–1702) on his treatises. The fragments, of different degrees of reliability, are important as (1) they reveal how the image of Descartes was shaped among his first followers and biographers; (2) they offer insights on his now lost manuscripts, to which De Raey had access after his death. They concern, amongst others, Descartes’s days at La Fléche, the original title of his Principia philosophiae, his inventum mirabile, a fragment of a conversation with him, and passages from an irretrievable French version of his Principia.