Cogito, ergo sum “I am thinking, therefore I exist” appears in the CSMK translation of Descartes's correspondence in French (“, ”) to colleagues at CSMK III 247. The earliest known translation as "I am thinking, therefore I am" is from 1872 by Charles Porterfield Krauth. As put compactly by Prof. Krauth (1872), "That cannot doubt which does not think, and that cannot think which does not exist. I doubt, I think, I exist." The phrase "cogito, ergo sum" is not used in Descartes's "Meditations on First Philosophy" but the term "the "cogito"" is used to refer to an argument from it. In the
Cogito and the History of Madness at the end of the renaissance and the beginning of the classical age. He then discusses the treatment of madness by Descartes in the "Meditations on First Philosophy". Foucault argues that Descartes refuses to recognise a commonality between himself and people who are mad and uses this dissociation as an excuse not to take madness seriously as a grounds for doubt. For Foucault this exclusion of madness by Descartes leads to a cogito that is more or less arbitrarily self-assured of its own rationality. Derrida argues that Descartes might appear to dismiss madness at the point of the meditation to