First principle foundationalist system of philosophy. He used the "method of doubt", now called Cartesian doubt, to systematically doubt everything he could possibly doubt, until he was left with what he saw as purely indubitable truths. Using these self-evident propositions as his axioms, or foundations, he went on to deduce his entire body of knowledge from them. The foundations are also called "a priori" truths. His most famous proposition is "Je pense, donc je suis." ("I think, therefore I am", or "Cogito ergo sum") Descartes describes the concept of a first principle in the following excerpt from the preface to the "Principles
Cogito and the History of Madness his point of departure for "Cogito and the History of Madness" is Foucault's 1961 book "Folie et déraison". Derrida's paper primarily relies on two sections of Foucault's work, the original 1961 preface in which Foucault makes a number of general comments about the book, setting forth his intentions and methodology, and two and a half pages at the start of the second chapter where Foucault links Descartes to an historical event that silenced madness at the end of the classical age. Foucault's 1961 text was heavily abridged for a popular edition in 1964 that formed the basis for Richard Howard's