Speech communities have belief systems about their language--origin myths,
beliefs about `good' and `bad' language, taboos, shibboleths, and so on.
These beliefs are part of the social conditions that affect
the maintenance and transmission of that language. Thus, the
fact that a language is diglossic is actually a feature of the
linguistic culture of the area where that language is used, rather than of the
language per se. To speak of a particular language as diglossic or not is at
best imprecise, since a language (e.g. English) as spoken in one part of the
world may exhibit little or no diglossia, while the same language (again using
English as an example) as used in a Caribbean creole community would have to
be considered diglossic. Speakers of a particular language can not be
characterized as diglossic; only their behavior, or the behavior of the speech
community can be considered diglossic. Thus, beliefs
and attitudes about the language condition the maintenance of diglossia as a
fact of linguistic culture. In the case of the Tamils, for example, it is the
set of beliefs about the antiquity and purity of Tamil that unites all members
of the linguistic culture in its resistance to any change in the corpus or
status of Tamil, by which of course is meant H-variety Tamil. (Schiffman
1974: 127).