Ferdinand de Saussure was born in Geneva, Switzerland on 26 November 1857. He showed an early interest in language: by the age of 13 he knew French, German, English and Latin, and by 15 he was looking at ways to explain the general system of language. He studied at the University of Geneva, and later taught the ancient language of Sanskrit there. Towards the end of his teaching career, between 1907 and 1911, he taught a new linguistics course that was groundbreaking in terms of structuralist thought.
Saussure was unusual in that he never wrote any of his ideas down in a form fit for publication. He prepared some lecture notes, but destroyed them thinking they were worthless. After his death, his students realised that his groundbreaking work should be published in book form, and they compiled his teachings and published them as the Course in General Linguistics (1916), made from their notes of lectures that Saussure had given.
Subsequently, Saussure's structuralist linguistics has influenced anthropology, psychoanalysis, literary criticism and semiotics. His work has influenced, to varying degrees, Roland Barthes, Claude Lévi-Strauss, Jacques Lacan, and Jacques Derrida. Saussure himself was influenced by Buddhist philosophy, but notably not by any of the earlier linguists.
Saussure departed from the earlier linguists in that he looked at the spoken word rather than the written word as the starting point of his enquiry. He came up with two important terms: langue, which is the system of language; and parole, what we actually do with language when we speak. He also linked linguistics to the general study of signs. (A sign is anything that stands for something other than itself, such as a red light that means “stop”).
One of Saussure's main points is that the linguistic sign does not link a name and a thing; instead it links a concept and an acoustic image. That is, language is more than just a list of terms that correspond to things. (An acoustic image is the mental image of a name that allows a language-user to say the name). However, Saussure later modified this theory into saying a linguistic sign links signifier and signified. A signifier is the sound we say when we say “cat”, and the signified is the concept of "cat". The word “cat” is the sign.
The second major point Saussure makes is that the linguistic sign is arbitrary, though the connections between signifier and signified can change. "Mouse" will always mean a furry mouse. But over time, language and its signs can change. “Mouse” can now also mean a computer mouse. New signifer-signified links may replace old ones or add to them.
Lastly, Saussure identified two ways of analysing language: synchronic and diachronic. Synchronic means looking at language at one point in time, and looking only at the relations between elements within a language. The diachronic method is to track the development of language over time as the language evolves and signs change through looking at individual elements at different times.