Linguistic Variability and Intellectual Development, Wilhelm von Humbolt's most famous work, was published by his brother Alexander posthumously, in 1836. It promptly established itself as a classic in the philosophy of language and has held that position ever since. With many examples from a vast multitude of languages, from Sanskrit to Delaware Indian, the author shows how character and structure of a language expresses the inner life and knowledge of its speakers and how their intellectual development is in turn shaped by their language.

"Humboldt's profound study is one of the classics of linguistic theory, a work of great insight and originality, of deep significance for the study of language and of human psychology and culture. His concept of linguistic forms and his ideas concerning linguistic creativiety are particularly fascinating and provocative, and of great contemporary interest." - Noam Chomsky

"This treatise, in our open and covert pro and con, has ever since determined the course of all subsequent philology and philosophy of language. . . . Astounding, obscure, and yet continuously stimulating." - Martin Heidegger