Self-reflection focus on the beatific vision after death. The 13th century pope Innocent III wrote about the essential misery of earthly existence in his ""On the misery of the human condition"" – a view that was disputed by, for example, Giannozzo Manetti in his treatise ""On human dignity."" A famous quote of Shakespeare's Hamlet (II, ii, 115-117), expressing the contrast of human physical beauty, intellectual faculty, and ephemeral nature: René Descartes famously and succinctly proposed: "Cogito ergo sum" (French: ""Je pense donc je suis""; English: ""I think, therefore I am""). The Enlightenment was driven by a renewed conviction, that, in 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;