Purists behave as if there was a vintage year when language achieved a measure of excellence which we should all strive to maintain. In fact, there was never such a year. The language of Chaucer's or Shakespeare's time was no better and no worse than that of our own - just different.
Interpretation
Language evolves over time, and no single period can be considered the definitive standard of excellence.
Jean Aitchison's quote highlights the notion that language is dynamic and constantly changes rather than adhering to a fixed standard of 'excellence.' The idea that there was a perfect period in history when language peaked is a myth; language in the time of great writers like Chaucer and Shakespeare was simply different, not inherently superior or inferior to contemporary language.
In practice
In a discussion about linguistic diversity, one might refer to Aitchison's quote to argue against prescriptive norms.
Language is a process of free creation; its laws and principles are fixed, but the manner in which the principles of generation are used is free and infinitely varied. Even the interpretation and use of words involves a process of free creation.
French is the most beautiful,β he said, βand Italian is the most poetic, and Russian the most powerful, German the most solid. But more business is done in English than in any other.
Those who sniff decay in every shift of sense or alteration of usage do the language no service. Too often for such people the notion of good English has less to do with expressing ideas clearly than with making words conform to some arbitrary pattern.
I have every reason to believe that an individual man or woman fluent in several tongues seduces, possesses, remembers differently according to his or her use of the relevant language.
The Hebrew language will go from the synagogue to the house of study, and from the house of study to the school, and from the school it will come into the home and... become a living language
I'm about as monolingual as you come, but nevertheless, I have a variety of different languages at my command, different styles, different ways of talking, which do involve different parameter settings.
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