Deleuze and Guattari argue that language does not serve to pass along information or to communicate knowledge; language, rather, establishes a sense of structure or order. Words are “order-words.” A basic level of information is needed to respond to language, but the point of language is not to communicate knowledge. Language is performative.
When a schoolmistress instructs her students on a rule of grammar or arithmetic, she is not informing them, any more than she is informing herself when she questions a student. She does not so much instruct as “insign,” give orders or commands. A teacher’s commands are not external or additional to he or she teaches. They do no flow from primary significations or result from information: am order always and already concerns prior orders, which is why ordering is redundancy. The compulsory education machine does not communicate information; it imposes upon the child semiotic coordinates processing all of the dual foundations of grammar (masculine-feminine, singular-plural, noun-verb, subject of the statement-subject of the enunciation, etc.). The elementary unit of language is the order-word.A Thousand Plateaus, 75-76
We learn not to believe anything politicians say, but maybe truthfulness isn’t the point. The point is not belief, agreement, or assent, but obedience. It’s not about credibility, but power. Deleuze & Guattari argue,
Language is not made to be believed but to be obeyed, and to compel obedience. . . . We see this in police or government announcements, which often have little plausibility or truthfulness, but say very clearly what should be observed and retained. The indifference to any kind of credibility exhibited by these announcements often verges on provocation. This is proof that the issue lies elsewhere.A Thousand Plateaus, 76
From a systems theory perspective, language does not transfer information from one system to another; information is synthesized within a system, which be as small as a dyad of two people (an interaction system). One person does not share or transfer information to someone else. Language is a medium, but it only become a form within a social system.
Order-words are not just a special type of word or statement.
“We call order-words, not a particular category of explicit statements (for example, in the imperative), but the relation of every word or every statement to explicit presuppositions, in other words, to speech acts that are, and can only be, accomplished in a statement. Order-words do not concern commands only, but every act that is linked to statements by a “social obligation.” (79)
Is the utterance “This coffee tastes bitter” and order or command? Yes, in the sense that someone is being commanded to respond in some way by at least acknowledging the statement; there is a social obligation (which assumes a social norm or expectation) to respond. If the listener just ignores the statement, she has refused the command. This is why Deleuze and Guattari claim that, for linguistics, pragmatics is central, rather than something in addition to semantics, syntactics, and phonematics.
Deleuze and Guattari are saying that language is primarily performative rather than representational; language does not represent reality or perceptions of reality.
Deleuze and Guattari go on the argue that all discourse is indirect,
If language always seems to presuppose itself, if we cannot assign it a nonlinguistic point of departure, it is because language does not operate between something seen (or felt) and something said, but always goes from saying to saying. We believe narrative consists not in communicating what one seen but in transmitting what one has heard, what someone else said to you. . . . The “first” language, or rather the first determination of language, is not the trope or metaphor but indirect discourse.A Thousand Plateaus, 76
This is a case of operational closure. Language never gets outside of itself. If language is indirect, this means we taste a cup of coffee and say “This tastes bitter,” we aren’t directly reporting a subjective experience or thought, we are repeating what we’ve heard someone else say. We might appear to say something novel or creative by combining or synthesizing words we’ve heard from diverse sources.