Saussure notes that phonetic changes in a language can have wider consequences on a language. One of these effects is “to break the grammatical link connecting two or more words.” Where linguistic signs once wore their derivation on their sound, a phonetic change breaks the link. In Latin, house-house is obviously linked ( mansio-mansionaticus ); in French the link is broken ( maison // menage ). Same for sheep-shepherd (Latin: vervex-vervecarius ; French: brebis // berger ). Saussure says that this change “has an affect on the value of the terms”; for example, “in some local patois French berger becomes specialized to mean ‘oxherd.’”
“Value” is not identical to “meaning,” but rather a combination of a sign’s position in a lexical system and its “exchange value” with its meaning (see my earlier post). But it’s significant that Saussure suggests that value may change when a sign’s lineage is broken, when we can no longer hear its etymological and historical links to other signs. Conversely, of course, its value is affected when we can hear those links. Even on the most strictly synchronic analysis, the value of linguistic signs is partly an effect (of a trace?) of diachronic considerations.