Mythology is the work and the product of the common consciousness. The generation existing at any time receives it from preceding generations; civilised generations from barbarous, and barbarous generations from their savage predecessors. If it grows in the process of transmission, and so reflects to some extent the changes which take place in the common consciousness, it changes but little in character. The common consciousness itself changes with exceeding slowness; it retains what it has received with a conservatism like that of children's minds; and, what it adds must, from the nature of the case, be modelled on that which it has received, and be of a piece with it. But, though the common consciousness changes but slowly, it does change: with the change from savagery to civilisation there goes moral development. Some of the myths, which are re-told from one generation to another, may be capable of becoming civilised and moralised in proportion as do those who tell them; but some are not. These latter are incidents in the personal history of the gods, which, if told at all, can only be told, as they had been told from the beginning, in all their repulsiveness. They survive, in virtue of the tenacity and conservatism of the common consciousness; and, as survivals, they testify to the moral development which has taken place in the very community which conserves them. By them the eye of modern science measures the development and the difference between the stage of society which originally produced them and the stage which begins to be troubled by them. They are valuable for the purposes of modern science because they are evidence of the continuity with which the later stages have developed from the earlier; and, also, because they are the first outward indications of the discovery which was eventually to be made, of the difference between mythology and religion--a difference which existed from the beginning of mythology, and all through its growth, though it existed in the sphere of feeling long before it found expression for itself in words.