Why the history of English literature is the diary of the rise, then decline, of English-speaking civilisation.
Literature is the Record of an Understanding
As use of language is the exercise of understanding, the literature of a community is the record of the nature of that community's understanding at the time. So the rise, then decline of the English-speaking public's understanding—which is the rise, then decline of English-speaking civilisation—is reflected by the history of English literature.
Literature Reveals the Start of a Civilisation
Chaucer is recognised as the father of the English language, which became a national tongue in the latter part of the 14th century, marking the beginning of English civilisation. The gradual rise of the community's ability to think clearly is demonstrated by the improvement from the awkward verse of Chaucer, to the brilliant prose of such writers as Edmund Burke, Edward Gibbon, Locke and Hume published in the eighteenth century. (Also see The Essay And the Beginning of Modern English Prose by A.A. Tilley.)
Literature Reveals the Golden Age of A Civilisation
The Concise Oxford English Dictionary (1938) defines Augustan as: 'connected with the reign of Augustus Caesar; best period of Latin literature'; which reveals that the Golden Age of Ancient Roman civilisation was the age of Augustus. But the Oxford English Dictionary also states that Augustan may be applied to 'any national literature', and the Augustan period of English literature was 1660–1780, which means this period was the Golden Age of English civilisation.
English Literature Now Declining
The decline of English civilisation is confirmed by the subsequent deterioration of its literature to the present day. W. H. Hudson stated in English Literature of the XIXth Century:
"That a great chapter in the annals of our literature came to a close about the beginning of the seventh decade of the nineteen century is universally admitted by historians and critics." — Part III, Chapter I
Modern Use of English Condemned
The use of English in contemporary works stands condemned by the textbooks of the twentieth century that set down the correct use of English needed for clear understanding. These works include Plain Words (1948) and The Complete Plain Words (1954) by Sir Ernest Gower, and Modern English Usage (1926) and The King's English (1908) by Fowler. The growing vagueness creeping into modern expression was also condemned by George Orwell in Politics and the English Language (1946). The very existence of these works show that people in the twentieth century were concerned that the popular use of language was becoming less precise and harder to understand. And this group included England's department of the Treasury, who commissioned Sir Ernest Gower to write books meant to repair the poor use of English by their own staff. Fowler revealed in 'Modern English Usage' that the use of words with no sensible meaning was becoming popular, especially with the young!
The decay of our language is so widespread and continual that Lord Dunsany claimed in 1943 that he could tell within ten years when any book of the twentieth century was written by the progress of the decay. The level of the decay in the year 2003 was described in detail by Don Watson in his book 'Death Sentence: the Decay of Public Language'. In 2011 a newspaper cartoon revealed that pompous meaningless phrases are now rampant.