Ferdinand de Saussure is the “father of modern linguistics” and “a master of a discipline which he made modern”. Saussure's ideas were developed along three lines: linguistics, sociology and psychology. In linguistics, he was greatly influenced by the American linguist W. D. Whitney, who was working within essentially the Neogrammarian tradition but raised the question of the sign. By insisting on the arbitrariness of the sign to emphasize that language is an institution, Whitney brought linguistics onto the right track. Following the French sociologist E. Durkheim, Saussure held that language is one of the “social facts”, which are ideas in the “collective mind” of a society and radically distinct from individual psychological acts. In psychology, Saussure was influenced by the Austrian psychiatrist S. Freud, who hypothesized the continuity of a collective psyche, called the unconscious.

Saussure saw human language as an extremely complex and heterogeneous phenomenon. Confronted with various aspects of language and different perspectives from which one might approach them, the linguist must ask himself what he is trying to describe. Saussure believed that language is a system of signs. Sounds count as language only when they serve to express or communicate ideas; otherwise they are nothing but noise. To communicate ideas, they must be part of a system of conventions, part of a system of signs. This sign is the union of a form and an idea, which Saussure called the signifier and the signified. Though we may speak of the signifier and signified as they are separate entities, they exist only as components of the sign. The sign is the central fact of language.

Saussure exerted two kinds of influence on modern linguistics. First, he provided a general orientation, a sense of the task of linguistics which had seldom been questioned. Second, he influenced modern linguistics in the specific concepts. Many of the developments of modern linguistics can be described as his concepts, i.e. his idea of the arbitrary nature of the sign, langue vs. parole, synchrony vs. diachrony, syntagmatic and paradigmatic relations, etc. Saussure’s fundamental perception is of revolutionary significance, and it is he that pushed linguistics into a brand new stage and all linguistic in the twentieth century are Saussurean linguistics.