The opposition between truth and falsity. The will to know is governed by a system of exclusions. The ancient discourse of truth in Greece had a performative nature, it was linked to power: but in the fifth century BC, the discourse of truth became linked to its meaning, its reference, the value of the utterance. Truth becomes semantic: it is displaced from the act to the utterance. It is the origin of philosophy, of the will to truth, born in opposition to the sophists. There is an evolution in this will to truth, not always due to a discovery. Around 1600 (Foucault is probably thinking of Francis Bacon) there is a new regime of classification and mensuration being born in England. It is the origin of technicism/positivism. The will to truth has a history of its own, which is not the history of constraining truths: a history of the delimitation of methods, of the objects of knowledge... It is sustained by institutional practices, among them the use of knowledge. This "truth" exerts pressure on the other discourses, which converge towards the discourse of truth. (E.g. realist or sincere literature). Thus, the modern penal code is no longer founded on power or spectacle, but on the scientific discourse of psychology, psychiatry, etc. (See on this point Foucault's work Discipline and Punish). That is, procedures of exclusion (1) and (2) become subordinated to (3): they become more fragile, while (3) grows all the time. But (3) is masked: in the sense that it necessarily ignores its links with power and desire. In Nietzsche, Artaud, Bataille... we appreciate a will to truth turned towards a critique of the notion of truth itself; they are the models for Foucault's analysis.