These licences are in all probability chiefly colloquial, and would not have been adopted in public harangues, to which the precepts of rhetorical writers commonly relate. But if the more elegant language of the Romans, since such we must suppose to have been copied by Terence for his higher characters, differed so much in ordinary discourse from their orthography, it is probable that the vulgar went into much greater deviations. The popular pronunciation errs generally, we might say perhaps invariably, by abbreviation of words, and by liquefying consonants, as is natural to the rapidity of colloquial speech.[486] It is by their knowledge of orthography and etymology that the more educated part of the community is preserved from these corrupt modes of pronunciation. There is always therefore a standard by which common speech may be rectified; and in proportion to the diffusion of knowledge and politeness the deviations from it will be more slight and gradual. But in distant provinces, and especially where the language itself is but of recent introduction, many more changes may be expected to occur. Even in France and England there are provincial dialects, which, if written with all their anomalies of pronunciation as well as idiom, would seem strangely out of unison with the regular language; and in Italy, as is well known, the varieties of dialect are still more striking. Now, in an advancing state of society, and especially with such a vigorous political circulation as we experience in England, language will constantly approximate to uniformity, as provincial expressions are more and more rejected for incorrectness or inelegance. But, where literature is on the decline, and public misfortunes contract the circle of those who are solicitous about refinement, as in the last ages of the Roman empire, there will be no longer any definite standard of living speech, nor any general desire to conform to it if one could be found; and thus the vicious corruptions of the vulgar will entirely predominate. The niceties of ancient idiom will be totally lost, while new idioms will be formed out of violations of grammar sanctioned by usage, which, among a civilized people, would have been proscribed at their appearance.