A linguistic system is a series of differences of sound combined with a series of differences of ideas; but the pairing of a certain number of acoust… - Ferdinand de Saussure

Language is a system whose parts can and must all be considered in their synchronic solidarity.

The linguistic entity is not accurately defined until it is delimited, i.e. separated from everything that surrounds it on the phonic chain. These delimited entities or units stand in opposition to each other in the mechanism of language.

Thus we may found the science for the study of the life of signs against the background of social life; it would form part of social psychology, and consequently of general psychology; we shall call it semiology (from Greek sēmeion — 'sign'). That science would explain to us in what signs consist of and by what laws they are governed. Since it is a science which does not yet exist, we do not know what it will be like; it has, however, a reason for its existence, its place is allocated in advance. Linguistics is only a part of that general science ; the laws which semiology will discover, will be applicable also to linguistics, which in turn will be linked with a domain clearly defined throughout the entirety of human affairs.