Pascal: “Men are so necessarily mad, that not to be mad would amount to another form of madness.” And Dostoievsky, in his diary of a writer: “It is not by confining one’s neighbor that one is convinced of one’s own sanity.”
We have yet to write the history of that other form of madness, by which men, in an act of sovereign reason, confine their neighbors, and communicate and recognize each other through the merciless language of non-madness; to define the moment of this conspiracy before it was permanently established in the realm of truth, before it was revived by the lyricism of protest. We must try to return, in history, to that zero point in the course of madness at which madness is an undifferentiated experience, a not yet divided experience of division itself. We must describe, from the start of its trajectory, that “other form” which relegates Reason and Madness to one side or the other of its action as things henceforth external, deaf to all exchange, and as though dead to one another.
This is doubtless an uncomfortable region. To explore it we must renounce the convenience of terminal truths, and never let ourselves be guided by what we may know of madness. None of the concepts of psychopathology, even and especially in the implicit process of retrospections, can play an organizing role. What is constitutive is the action that divides madness, and not the science elaborated once this division is made and calm restored. What is originative is the caesura that establishes the distance between reason and non-reason; reason’s subjugation of non-reason, wresting from it its truth as madness, crime, or disease, derives explicitly from this point
Michel Foucault, Madness and Civilization – A History of Insanity in the Age of Reason, Preface