Synchrony vs. diachrony

Studying how a language changes over time and studying how it works as a system at one moment are separate disciplines; neither is inferior, but a linguist picks one.

Put simply Saussure: studying how a language changes over time and studying how it works as a whole at one moment are two separate fields. Neither is worse, but a linguist does one or the other.

Proper study of language brackets the signified, the real cat the word points to, and examines how signs work as a system at one moment.

Put simply Saussure: to study language properly, set aside the real things words point to, such as the actual cat. Look instead at how words work together as a system at a given moment.

In the text In the Course in General Linguistics (1916; Baskin translation, p. 66), Saussure writes: "The linguistic sign unites, not a thing and a name, but a concept and a sound-image."

A language's present state can be fully described without knowing its past, much as a chess position is legible to a passerby who never saw the earlier moves.

Put simply Saussure's comparison: a passerby can read a chess position without having seen the earlier moves. Likewise, a language as it stands now can be fully described without knowing its history.

Nobody is present at a language's birth: every speaker arrives into one already in place, so its origins are never witnessed.

Put simply Saussure: no one is around when a language is born. We are all born into a language that already exists, so nobody sees how it began.

Structuralism is ahistorical, and amoralizing too, in that it tends to steer clear of value judgments.

Put simply Shore: structuralism sets history aside, and it tends to avoid judging things as good or bad.

Différance packs both meanings of the French différer, differing and deferring, together: meaning is other than its neighbors and still to come, so synchronic and diachronic are handled together.

Put simply Derrida's word "différance" joins "differ" and "defer." Meaning comes from differing from other words, and it is never finished, always still to come. So he studies language at one moment and over time together.