“And if, now, we try to assign a value, in and of itself, outside its relations with the dream and with error, to classical unreason,we must understand it not as reason diseased, or as reason lost or alienated, but quite simply as reason dazzled. Dazzlement is night in broad daylight, the darkness that rules at the very heart of what is excessive in light’s radiance. Dazzled reason opens its eyes upon the sun and sees nothing, that is, does not see; in dazzlement, the recession of objects toward the depths of night has as an immediate correlative the suppression of vision itself; at the moment when it sees objects disappear into the secret night of light, sight sees itself in the moment of its disappearance. To say that madness is dazzlement is to say that the madman sees the daylight, the same daylight as the man of reason (both live in the same brightness); but seeing this same daylight, and nothing but this daylight and nothing in it, he sees it as void, as night, as nothing; for him the shadows are the way to perceive daylight. Which means that, seeing the night and the nothingness of the night, he does not see at all. And believing he sees, he admits as realities the hallucinations of his imagination and all the multitudinous population of night. That is why delirium and dazzlement are in a relation which constitutes the essence of madness, exactly as truth and light, in their fundamental relation, constitute classical reason. In this sense, the Cartesian formula of doubt is certainly the great exorcism of madness.
Descartes closes his eyes and plugs up his ears the better to see the true brightness of essential daylight; thus he is secured against the dazzlement of the madman who, opening his eyes, sees only night, and not seeing at all, believes he sees when he imagines. In the uniform lucidity of his closed senses, Descartes has broken with all possible fascination, and if he sees, he is certain of seeing that which he sees. While before the eyes of the madman, drunk on a light which is darkness, rise and multiply images incapable of criticizing themselves (since the madman sees them), but irreparably separated from being (since the madman sees nothing). Unreason is in the same relation to reason as dazzlement to the brightness of daylight itself. And this is not a metaphor. We are at the center of the great cosmology which animates all classical culture. The “cosmos” of the Renaissance, so rich in internal communications and symbolisms, entirely dominated by the interacting presence of the stars, has now disappeared, without “nature” having yet assumed its status of universality, without its having received man’s lyrical recognition, subjecting him to the rhythm of its seasons. What the classical thinkers retain of the “world,” what they already anticipate in “nature,” is an extremely abstract law, which nonetheless forms the most vivid and concrete opposition, that of day and night. This is no longer the fatal time of the planets, it is not yet the lyrical time of the seasons; it is the universal but absolutely divided time of brightness and darkness. A form which thought entirely masters in a mathematical science— Cartesian physics is a kind of mathesis of light—but which at the same time traces the great tragic caesura in human existence: one that dominates the theatrical time of Racine and the space of Georges de la Tour in the same imperious fashion. The circle of day and night is the law of the classical world: the most reduced but the most demanding of the world’s necessities, the most inevitable but the simplest of nature’s legalities.”
– Michel Foucault
Madness & Civilization