Custom, rite, and belief treated in this fashion become veritable monuments of history--a history too ancient to have been recorded in script, too much an essential part of the folk-life to have been lost to tradition. We may hope to restore therefrom the surviving mosaic of ancient institutions, ancient law, and ancient religion, and we may further hope, with this mosaic to work upon, to restore much of the entire fabric which has been lying so many centuries beneath the accumulated and accumulating mass of new developments representing the civilisation of the Western world. III It is only here that we can discover the point where we may properly commence the work of comparative folklore. An item of folklore which stands isolated is practically of no use for scientific investigation. It may be, as we have seen, that the myth is in its primary stage as a sacred belief among primitive people, in its secondary or folk-tale stage as a sacred memory of what was once believed, in its final or legendary stage when it does duty in preserving the memory of a hero or a place of abiding interest. It may be, as we have seen, that the custom, rite, or belief is a mere formula without purpose or result, a mere traditional expression of a purpose without formula or result, a mere statement of result without formula or purpose. We must know the exact position of each item before we begin to compare, or we may be comparing absolutely unlike things. The exact position of each item of folklore is not to be found from one isolated example. It has first to be restored to its association with all the known examples of its kind, so that the earliest and most complete form may be recorded. That is the true position to which it has been reduced as a survival. This restored and complete example is then in a position to be compared either with similar survivals in other countries on the same level of culture, or within the same ethnological or political sphere of influence, or with living customs, rites, or beliefs of peoples of a more backward state of culture or in a savage state of culture. Comparison of this kind is of value. Comparison of a less technical or comprehensive kind may be of value in the hands of a great master; but it is often not only valueless but mischievous in the hands of less experienced writers, who think that comparison is justified wherever similarity is discovered.