René Descartes remains to the Panthéon, he was reburied in the Abbey of Saint-Germain-des-Prés in 1819, missing a finger and skull. His skull is on display in the Musée de l'Homme in Paris. Initially, Descartes arrives at only a single first principle: I think. Thought cannot be separated from me, therefore, I exist ("Discourse on the Method" and "Principles of Philosophy"). Most famously, this is known as "cogito ergo sum" (English: "I think, therefore I am"). Therefore, Descartes concluded, if he doubted, then something or someone must be doing the doubting, therefore the very fact that he doubted proved his existence. "The
Cogito, ergo sum one's belief in their own existence would be secure, for there is no way one could be deceived unless one existed in order to be deceived. But I have convinced myself that there is absolutely nothing in the world, no sky, no earth, no minds, no bodies. Does it now follow that I, too, do not exist? No. If I convinced myself of something [or thought anything at all], then I certainly existed. But there is a deceiver of supreme power and cunning who deliberately and constantly deceives me. In that case, I, too, undoubtedly exist, if he deceives me;