Every culture has its own way of ‘speaking’. Within the general frames of logic and grammar, it applies its own rules of reasoning, has distinctive ways of using language, its own favoured stories and style of storytelling. All this comes together in the discourse (or discours in French) of a culture. It is not primarily an aesthetic construction; its objective and result is the regulation of human behaviour, of intercourse in society, and of the way its institutions operate and justify themselves. This means that discourse is not just communication, but an indispensable part of the exercise and legitimation of power. The discourse largely determines the relations between people.

A culture’s view of reality, its ideas on the limits of human perception, and its believes about the proper use of language form a whole, which distinguishes the culture from previous or later historical periods and their culture. The changing outlook on science from one period to another is a major component of what defines a culture and a culture’s characteristic discourse. Canguilhem and Foucault (among others) have stressed the importance of discontinuities in the way the sciences develop, denying that there is a continuous progress in science’s evolution.