A binary pair introduced by Ferdinand de Saussure to define the two available temporal axes for the analysis of language, which can logically be extended to encompass virtually all forms of human activity. Linguistics, in Saussure's time, approached the problem of the multiplicity of languages by trying to trace each of them back to a handful of common sources (in much the same way as evolutionary biologists approach the problem of the multiplicity of species). This approach was deemed diachronic by Saussure because it looks for the production of difference across time. But for Saussure this ignored the (to him, more interesting and important) problem of how to account for the existence and operation of language itself. To get a handle on this, he insisted that it was necessary to take a snapshot of language at a particular time and effectively produce a freeze-frame of it. This approach he referred to as synchronic. By freezing time, or better ignoring its effects, Saussure thought it would be easier to see that which was eternal and universal.
F. Jameson The Prison-House of Language: A Critical Account of Structuralism and Russian Formalism (1972).J. Sturrock Structuralism (1986).
Subjects: Linguistics — Literary Theory and Cultural Studies.