Ferdinand de Saussure

Ferdinand de Saussure (1857–1913) was a Swiss linguist whose posthumously published Course in General Linguistics (1916) founded modern structural linguistics and influenced semiotics, anthropology, literary theory, and philosophy. Saussure's key insight — that linguistic signs are arbitrary and that meaning arises from differential relations within a system rather than from reference to external reality — became the foundational method of twentieth-century structuralism.

Saussure distinguished langue (the underlying system of a language) from parole (individual speech acts), and the signifier (sound-image) from the signified (concept). These distinctions established that language is a system of differences rather than a nomenclature of pre-existing ideas.