[...] the meaningful combinations of vowels and consonants [...] derive their functional significance from the arbitrary associations between them and their meanings established by various societies in the course of an uncontrollably long period of historical development. That these associations are essentially arbitrary or conventional may be seen at once by considering such a proportion as phonetic entity 'boy': idea (or reference) 'boy' = phonetic entity 'man': idea (or reference) 'man'.
- Sapir (1929), a pag.40