“And so, for knowledge, the being of things is an illusion, a veil that must be torn aside in order to reveal the mute and invisible violence that is devouring them in the darkness.” (303 The Order of Things Foucault)
A thought is only valid once it has been structured in the form we have been taught to think and communicate. Our knowledge of ourselves as human beings is limited by what science has discovered in its dissections of our bodies. Our labor is worth only as much as its relation to the exchange values of a global economy, and the satisfaction of needs, not to mention the profits of someone else. Further, Man only exists once he can represent himself or be represented in formalization. Foucault’s book carefully dissects the way in which thought is related to formalization; life on earth can be understood only when it becomes represented in a domain of order. The vast continuity of life becomes fragmented and distinguished through intricate systems of difference, all is passed through a grid of arbitrary distinctions. Knowledge becomes possible in three general arenas of representational form known as “human sciences”: Language, Biology, Economics.
At this point in history, we are born into a vast system of order and formulate our conceptions of identity, interaction, and life upon a pre-existing grid of understanding and representation. We are subject to a common control and limit that is no longer interested in the possibilities of being, but rather in the conditions of life. At any given point the structure of individual existence finds itself with a certain number of possible choices (and of excluded possibilities). Inversely, the points of choice in a social structure encounters a certain number of possible individuals (and those individuals who must be excluded). The creation of the social sphere parallels the creation of meaning in linear language in the sense that every point produces a possible choice between several words (and excluded words). Labor is geared towards the production of things that will satisfy “needs”, but our “needs” have been determined in advance, regulated and institutionalized based on the conditions of life. (see previous post Instincts and Institutions). Therefore, the human sciences exist wherever there is analysis; the sciences are an attempt to deliver to human consciousness the conditions of its forms, needs, and contents.
“These constituent models are borrowed from the three domains of biology, economics, and the study of language. It is upon the projected surface of biology that man appears as a being possessing functions – receiving stimuli (physiological ones, but also social, interhuman, and cultural ones), reacting to them, adapting himself, evolving, submitting to the demands of an environment, coming to terms with the modifications it imposes, seeking to erase imbalances, acting in accordance with regularities, having, in short, conditions of existence and the possibility of finding average norms of adjustment which permit him to perform his functions. On the projected surface of economics, man appears as having needs and desires, as seeking to satisfy them, and therefore as having interests, desiring profits, entering into opposition with other men; in short, he appears in an irreducible situation of conflict; he evades these conflicts, he escapes from them or succeeds in dominating them, in finding a solution that will – on one level at least, and for a time – appease their contradictions; he establishes a body of rules which are both a limitation of the conflict and a result of it. Lastly, on the projected surface of language, man’s behavior appears as an attempt to say something; his slightest gestures, even their involuntary mechanisms and their failures, have a meaning; and everything he arranges around him by way of objects, rites, customs, discourse, all traces he leaves behind him, constitute a coherent whole and a system of signs. Thus, these three pairs of function and norm, conflict and rule, signification and system completely cover the entire domain of what can be known about man.” (390 The Order of Things Foucault)
Man is trapped in the realm of representation of the human sciences . Man has the potential to cease, without the human being becoming extinct. There is always the possibility of the Return. Because of this, the human is born as a Double. There is Man, and there is his Other, his twin, brother, accompanying figure of what remains Unthought in him. To think is to enter a realm of representation, because of this we each have an Other with us at all times, occupying our human potential in what is Unthought. As long as representation passes for the general element of thought, Man is trapped in representation, while his Other is trapped in the density of what he does not think. The Other is the shadow cast by man in the field of Knowledge. The Unthought accompanies man, mutely and uninterruptedly. Psychology and Psychoanalysis attacked the Unthought with the concept of the Unconscious. But the Unthought is incapable of being absorbed; the concept of The Unconscious fails in absorbing the Unthought because a concept of the Unconscious is only illumined by a reflexive form of knowledge – Psychology is built within a domain of human science and established as a collection of signs and significations. This perhaps, highlights the paradox of the Unthought; to bring the unconscious to the conscious arena of knowledge is an attempt at eclipsing the Other with the Same. Although the concept of the unconscious brought knowledge into an edge of the blind stain of the Other, there is still no real possibility of consuming the shadow, only of creating a false illusion of representation.
“The inexhaustible double presents itself to reflection as the blurred projection of what man is in his truth, but that also plays the role of a preliminary ground upon which man must collect himself and recall himself in order to attain his truth. For though this double may be close, it is alien, and the role, the true undertaking, of thought will be to bring it as close to itself as possible; the whole of modern thought is imbued with the necessity of thinking the Unthought – of reflecting the contents of the In-itself in the form of the For-itself, of ending man’s alienation by reconciling him with his own essence, of making explicit the horizon that provides experience with its background of immediate and disarmed proof, of lifting the veil of the Unconscious, of becoming absorbed in its silence, or of straining to catch its endless murmur.” (356 The Order of Things Foucault)
Source:
Foucault, Michel. The Order of Things. London: Routledge, 2002. Print.
view from a burrow 
“all is passed through an arbitrary grid of distinctions.” Borges aside, there are no blue tigers, and though taxonomies and classificatory systems could be different, they would not endure long if they didn’t yield knowledge. Foucault has it backward; we don’t force mammals into that category. The category is based on inductive discovery of shared traits that illuminate physiology, agriculture, biology and numerous other fields. Were this not so, the classifications would be modified or abandoned for more empirically based schemas.
There’s no doubt that forms of acquisitive understanding are productive. But I think part of Foucault’s project is to illuminate that the systems that appear to yield Knowledge are subject to change, be rewritten, and form new classifications. It’s only retrospectively that we see the flaws in 16th century Knowledge, but at the time, there were things considered True and accepted as valid Knowledge that have since disintegrated into falsity or uselessness. It’s difficult to look at our time the same way because we are living in it, but it’s possible that a few hundred years from now, our taxonomies and classificatory systems will have changed, been reordered, modified and abandoned. It’s not that these systems are inherently sinister, or bad, or even wrong – it’s just that the systems of Knowledge that we accept as True are only one of many different ways to classify and order things, and often they are held in place so that they may maintain a system of operations in a power structure. The distinctions are arbitrary not because they have no purpose, but because they are only one of many possibilities – whether we measure something in inches or centimeters doesn’t really matter, as long as there is an exterior system to refer to and validate the measurement. Thinking and communicating must first be structured in a way that we are sure to both understand, this system of communication in language is productive, but it is an external system that we must utilize and pass through, the system itself is arbitrary because it is only one of many possibilities of constructing exchange.