Rationalism senses. For instance, his famous dictum, "cogito ergo sum" or "I think, therefore I am", is a conclusion reached "a priori" i.e., prior to any kind of experience on the matter. The simple meaning is that doubting one's existence, in and of itself, proves that an "I" exists to do the thinking. In other words, doubting one's own doubting is absurd. This was, for Descartes, an irrefutable principle upon which to ground all forms of other knowledge. Descartes posited a metaphysical dualism, distinguishing between the substances of the human body (""res extensa"") and the mind or soul (""res cogitans""). This
Cogito and the History of Madness translation of the text into English as "Madness and Civilization". The abridged 1964 edition removed the pages concerning Descartes on which Derrida had explicitly based his argument in "Cogito and the History of Madness." These pages on Descartes were only made available in English with Jean Khalfa's 2006 translation of Foucault's work on madness. Derrida makes an allusion to the master–slave dialectic in Hegel's "Phenomenology of Spirit" in the opening pages of "Cogito and the History of Madness." Foucault writes at the start of the second chapter of the "History of Madness" of a strange violent event that silenced madness