Back of the purely objective system of sounds that is peculiar to a language and which can be arrived at only by a painstaking phonetic analysis, there is a more restricted 'inner' or 'ideal' system.
- Sapir (1921), a pag.55

The inner sound system [...] is a real and an immensely important principle in the life of a language. It may persist as a pattern, involving number, relation, and functioning of phonetic elements .
- Sapir (1921), a pag.55

Two historically related languages or dialects may not have a sound in common, but their ideal sound-systems may be identical patterns.
- Sapir (1921), a pag.55

Every language [...] is characterized as much by its ideal system of sounds and by the underlying phonetic pattern (system, one might term it, of symbolic atoms) [...]
- Sapir (1921), a pag.56