This book is not a conventional history of English. Rather, it tries to show how the discipline of linguistic history may be pursued-a rather different matter. It does this by using selected phenomena in the history of English to exemplify the dynamic processes of change involved. In so doing it tries to address the question of linguistic change: why does change happen, and why does it happen at the time and in the way that it does?
In answering these questions, this book, rather obviously, holds it as axiomatic that human language is both a cultural and a systematic phenomenon, and that both these characteristics need to be borne in mind when addressing the question of linguistic change. On the one hand, it is held here that the various changes at an intralinguistic level which are held to be the prime concern of writers of linguistic history-changes in writing systems, pronunciation, grammar or lexicon-cannot be meaningfully accounted for without reference to the extralinguistic contexts (historical, geographical, sociological) in which these phenomena are situated. Language is plainly a social phenomenon-if societies did not exist, there would be no language-and it follows from this that an asocial approach to its study has a comparatively limited (because formal) interest.
This conclusion applies most uncontroversially to diachronic linguistics (i.e. time-situated linguistics). If we attempt to explain language change entirely intralinguistically, without ultimate reference to extralinguistic factors, then, it is argued here, the explanation will ultimately fail.
But it is also held here that linguistic change can operate intralinguistically, that is, without immediate reference to external, non-linguistic factors. The key argument in support of this axiom is that linguistic changes, once they have themselves been implemented, interact with each other to produce further change.
To clarify these points, it may be useful to model the structure of natural language diagrammatically. Figure 1.1 is an attempt to schematise the way in which language is used to communicate ideas. The deepest level of language, in this diagram, is semantics, that is, the level of meaning. (There