Abstractness and psychological reality

A fundamental question in the theory of phonology has been “how abstract is phonology?”, specifically, how different can the underlying and phonetic forms of a word be? The essential question is whether grammars use entities that are not directly observed. Related to this is the question whether a linguistic model requiring elements that cannot be directly observed reflects what the human mind does. The very concept of a mental representation of speech, such as a phonological surface form like [sɔks] socks which is not itself an observable physical event, requires abstracting away from many specifics of speech. Without generalizing beyond the directly observable, it would be impossible to make even the most mundane observations about any language. The question is therefore not whether phonology is abstract at all, but rather what degree of abstractness is required.

If underlying representations are fully concrete – if they are the same as surface representations – the underlying forms of English [kh ɔrts] courts and [kh owdz] codes would be /kh ɔrt-s/ and /kh owd-z/. Such an extremely surface-oriented view of phonology would ignore the fact that the words have in common the plural morpheme, whose pronunciation varies according to the environment. By hypothesizing that the underlying form of [kh ɔrts] is /kh ɔrt-z/, we can say that the plural pronounced s in [kh ɔrts] and the plural pronounced z in [kh owdz] are one and the same thing. Such abstractness in phonological analysis yields the benefit of explaining the similaries in pronunciation of the various realizations of the plural morpheme.