In the midst of the serene world of mental illness, modern man no longer communicates with the madman: on the one hand is the man of reason, who delegates madness to the doctor, thereby authorising no relation other than through the abstract universality of illness; and on the other is the man of madness, who only communicates with the other through the intermediary of a reason that is no less abstract, which is order, physical and moral constraint, the anonymous pressure of the group, the demand for conformity. There is no common language: or rather, it no longer exists; the constitution of madness as mental illness, at the end of the eighteenth century, bears witness to a rupture in a dialogue, gives the separation as already enacted, and expels from the memory all those imperfect words, of no fixed syntax, spoken falteringly, in which the exchange between madness and reason was carried out. The language of psychiatry, which is a monologue by reason about madness, could only have come into existence in such a silence.
... The Greeks had a relation to a thing they called hubris. The relation was not solely one of condemnation: the existence of Thrasymachus [“ListenI say that justice is nothing other than the advantage of the stronger”] or that of Callicles, is proof enough of that, even if their discourse comes down to us already enveloped in the reassuring dialectics of Socrates. But the Greek Logos had no opposite.
European man, since the depths of the Middle Ages, has had a relation to a thing that is confusedly termed Madness, Dementia, or Unreason. It is perhaps to that obscure presence that Western Reason owes something of its depth, as with the threat of hubris [to] the sophrosyne of Socratic speechmakers. In any case, the ReasonUnreason relation constitutes for Western culture one of the dimensions of its originality: it accompanied it long before Hieronymous Bosch, and will follow it long after Nietzsche and Artaud.
But what then is this confrontation below the language of reason? Where might this interrogation lead, following not reason ... but seeking to retrace in time this constant verticality [ie. of madness], which, the length of Western culture, confronts it with what it is not, measuring it with its own extravagance? Towards what region might it take us, which was neither the history of knowledge nor history plain and simple, which was commanded neither by the teleology of truth nor the rational concatenation of causes, which only have value or meaning beyond the division? A region, no doubt, where it would be a question more of the limits than of the identity of a culture.
Michel Foucault, History of Madness (2006: xxviii-xxix)