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 distinctiveness of self-evident propositions — to establish true and justified propositions despite having adopted a method of generalized doubt. As a consequence of this demonstration, Descartes considers science and mathematics to be justified to the extent that their proposals are established on a similarly immediate clarity, distinctiveness, and self-evidence that presents itself to the mind. The originality of Descartes's thinking, therefore, is not so much in expressing the "cogito" — a feat accomplished by other predecessors, as we shall see — but on using the "cogito" as demonstrating the most fundamental epistemological principle, that science and mathematics are justified by