Idealism is not possible to infer the 'I' as an object (Descartes' "cogito ergo sum") purely from "the spontaneity of thought". Kant focused on ideas drawn from British philosophers such as Locke, Berkeley and Hume but distinguished his transcendental or critical idealism from previous varieties; Kant distinguished between things as they appear to an observer and things in themselves, "that is, things considered without regard to whether and how they may be given to us". We cannot approach the "noumenon", the "thing in Itself" () without our own mental world. He added that the mind is not a blank slate, "tabula
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