 In her dissertation, Weil attempts to think with Descartes in order to find foundational knowledge. Like Descartes, she argues for the existence of self, God, and world. Her cogito, however, was a decisive break from his: “I can, therefore I am” (Je puis, donc je suis) (1929–1930 “Science and Perception in Descartes”, FW 59). The self has the power of freedom, Weil argues, but something else—the omnipotent, God—makes the self realize that it is not all-powerful. Self-knowledge, then, is capability always qualified by the acknowledgment that one is not God. She maintained a kind of Cartesian epistemology during her time as a teacher, early in her academic life. In Lectures on Philosophy (1978 LP), a collection of lecture notes taken by one of her students during the academic year 1933–1934 at a girl’s lycée in Roanne, we find that Weil is initially critical of sensations as grounds for knowledge, and thereby critical of empiricist epistemology (LP 43–47).