These phonetic causes enter at once into conflict with the strictly etymologic formations of the language, moulding its sounds, decomposing its structure, and interchanging the organs producing the sounds; and these effects are perpetuated by circumstances causing the separation or isolation of the people who have adopted them, while new words and combinations are added to their vocabulary by new wants arising in their separate state, by their advance in social condition, or by the peculiarities of their new condition. Thus innumerable dialects spring up. Whenever a difference of situation takes place among the people composing the aggregate by whom the original language was spoken, a diversity of dialect is at once created. In these dialects are preserved the bones of the mother tongue; and it is only by a comparison of these that her full character can be ascertained.

This tendency of the mother tongue, to break up into as many dialects as there are shades of difference in the position and tendencies of its speakers, is only arrested by the formation of a cultivated dialect, created when the wants of an educated or cultivated class in the community demand a common medium of interchanging their ideas. This cultivated language is usually first formed by poetry, completed by writing, and adopted by education. Its first stage is that of the language in which the songs and poems, the first literature of a rude people, are recited by its bards, its earliest literary class; and, by the introduction of the art of writing, it passes over into the written speech. It then becomes a common dialect, spoken and written by the cultivated class of the community, and to a knowledge of which a portion of the people are raised by education.

This cultivated or written language may have been originally one of the numerous dialects spoken by the people composing the community, and which circumstances have elevated into that position; or it may have been introduced from another country speaking a sister dialect, which has preceded it in cultivation; or it may, like the German, have been developed from an unspoken variety of the language created by other causes and for other purposes. In the one case, the language first cultivated by poetry passes over into the written language. In the other, it remains an indigenous, cultivated, spoken language, which is antagonistic to, and contends with, the imported written speech till the influence of the latter prevails, and it is either extinguished by it, or remains as popular poetry in the vernacular tongue, while everything prose is absorbed.

But however it originates, the spoken dialects still remain as the vernacular speech of portions of the community. They are not the children or creatures of the written speech, still less corruptions of it, but are equally ancient, and retain much of the elements of the original language which the written speech has rejected.

The formation of a cultivated or written language is always an eclectic process. It selects, it modifies, and it rejects, while the living dialects retain many of the forms and much of the structure modified and rejected by it. Hence, for the study of the character and formation of the mother tongue, the living spoken dialects are of the first importance; and a restricted attention to the written language, and the contemptuous rejection of everything in the spoken dialects which vary from it, as barbarisms and corruptions, is simply to part with much valuable material for the study, and to narrow the range of inquiry.[19]

Perhaps the English language affords an illustration of these remarks. As a written and cultivated language, it took its rise in England, but was introduced from England into Scotland.

In England, the provincial dialects have remained as the spoken language of the uncultivated class in the respective provinces side by side with it; but their antiquity and their value for philological purposes is fully acknowledged. No one dreams of viewing them as merely corruptions of the written language, arising from rudeness and ignorance.

In Scotland, the English language has been introduced as the written or cultivated language, but a different form of the language, the Broad Scotch, is the vernacular speech of the people, and preceded the English language as the written language of the country in which its earliest literature was contained. Its great value, as an early form of the original Anglic tongue which formed the language of the country, is so fully acknowledged, that Jamieson’s Dictionary of the Scotch language has been called the best dictionary of the English language. It has ceased to be a vehicle for prose composition; but there exists a ballad literature in the Scotch dialect which has resisted the absorbing influence of the English.

So it was also in the Scotch Highlands, where the written and cultivated language did not originate in this country, but was brought over from Ireland in the sixth century, though in this case the analogy is not so great, from the various dialects of the Gaelic having probably at all times approached each other much more nearly than the provincial dialects of England and Scotland, and been more greatly influenced by the written language.

In order to determine the philological position and value of the Scotch Gaelic, it is necessary to form a more accurate conception of the historical position of the people who spoke it, and of the influences to which they have been exposed, and by which the language was likely to be affected.