The Scottish ballads are undoubtedly, in their present form, the outcome of a long and strenuous process of selection. In its earlier stages, the ballad was not written down but passed from mouth to mouth. Additions, interpolations, changes infinite must have been made in the course of transmission and repetition. Like a hardy plant, it had the power to spread and send down fresh roots wherever it found favourable soil; and in its new ground it always, as we shall see, took some colour and character from the locality, the time, and the race. Golden lines and verses may have been shed in the passage from place to place and down the centuries. But less of this happened, we may feel sure, than a purging away of the dross. As a rule, what was fittest--what was truest to nature and to human nature--survived and was perpetuated in this evolution of the ballad. When, in the course of its progress, it gathered to itself anything that was precious and worthy of remembrance, then, by the very law of things, this was seized and stored in the memories of the listeners and handed down to future generations.
But this process of purging and refining the ballad, so that it shall become--like the language, the proverbs, the folklore and nursery tales, and the traditional music of a nation--the reflection of the history and character of the race itself, if it is to be genuine, must go on unconsciously. As soon as the ballad is written down--at least as soon as it is fixed in print--the elements of natural growth it possesses are arrested. It is removed from its natural environment and means of healthy subsistence and development; and from a hardy outdoor plant it is in danger of becoming a plant of the closet--a potted thing, watered with printer's ink and trimmed with the editorial shears. Ballads have sprung up and blossomed in a literary age; but as soon as the spirit that is called literary seizes upon them and seeks to mould them to its forms, they begin to droop and to lose their native bloom and wild-wood fragrance. It is because they neglect, or are ignorant of, literary models and conventions, and go back to the 'eternal verities' of human passion and human motive and action--because they speak to 'the great heart of man'--that they are what they are.
