Chapter 4: “Speaking” applies the framework and concepts established by Chapter 3 to discourse about language and grammar in the Classical Age. The study of language was called “general grammar” at the time, which highlights the value placed in the mechanical functions of language. The chapter is divided into seven parts.

In part one (“Criticism and Commentary”), Foucault examines the discourse around Classical Age language usage. Criticism—the act of critiquing a thing to understand and explore its purpose—replaced 16th-century commentary, the act of writing comments and addendums upon previous information while not interrogating the past information. The criticism of language was categorized in four parts: Criticism of words themselves; of rhetoric and modes of discourses; of tropes; and of relation (how criticism functions).

In part two (“General Grammar”), Foucault looks at the discipline of general grammar. General grammar was created in the Classical Age as a way of ordering and taxonomizing language and ways of thinking about language. The goal of general grammar was to make language perfectly understood and therefore perfectly capable of being used analytically and logically.

In part three (“The Theory of the Verb”), Foucault looks at the value placed on verbs by general grammarians.