Wilhelm von Humboldt's (1767–1835) major work, On the Diversity of Human Language Construction and Its Influence on the Mental Development of the Human Species (Über die Verschiedenheit des menschlichen Sprachbaues und ihren Einfluss auf die geistige Entwicklung des Menschengeschlechts), labeled the “Kawi Introduction” by his editor, has been called “the first great book in general linguistics” (Bloomfield 1933, 133). It anticipates contemporary generative linguistics and, at the same time, is considered a precursor to linguistic relativism as developed early in the twentieth century by the anthropologists Edward Sapir (1884–1939) and Benjamin Whorf (1897–1941). It is even seen as anticipating the later philosophy of Ludwig Wittgenstein.

That Humboldt appears to fit generativism as well as relativism is striking because, strictly speaking, generativism and relativism in linguistics are incompatible. Whereas generativism looks for the universal linguistic and mental structures rooted in human nature, relativism denies such shared structures common to all human beings. Instead, relativism focuses on the diversity of linguistic structures and how these structures determine the way in which human beings see and know the world. But it should not be surprising that both of these trends have been located in Humboldt's work on language because his work is a crossroads of the directions set out by Leibniz and Condillac. Humboldt attempts to meld together the system and use perspectives on language, as well as the angelic and the earthly, into a synoptic empirical and philosophical theory of human language.