Finally, an interpretation, that has frequently been alluded to in the preceding pages of this introduction, is the _physical_, or interpretation from nature,—impersonation of the visible workings of nature. The divinities are the forces and phenomena of nature personified; and evidence of the correctness of this view can be abundantly presented by defining etymologically names of the several divinities, their attributes, dwellings and achievements, and by showing how faithfully the works of the gods correspond with the events and scenes of the outward world. There is no doubt that this is the true interpretation of all mythologies; and that it is, so to speak, the key to the Norse mythology, it is hoped will be sufficiently demonstrated in the second part of this book in connection with the myths themselves; but the ethical, or perhaps better the spiritual, interpretation must by all means be added. The spiritual or ethical and the physical interpretation must be combined. In other words, we can scarcely make the interpretation too _anthropomorphic_. The phenomena and forces of nature have been personified by our forefathers into deities, but the myths have been elaborated to suit and correspond with the moral, intellectual and emotional nature,—the inner life of man. The deities have been conceived in a human form, with human attributes and affections. The ancient Norsemen have made their mythology reflect human nature, and have clothed the gods with their own faculties of mind and body in respect to good and evil, virtue and vice, right and wrong. As Rudolf Keyser beautifully expresses himself: The gods are the ordaining powers of nature clothed in personality. They direct the world, which they created; but beside them stand the mighty goddesses of fate and time, the great norns, who sustain the world-structure, the all-embraceing tree of the world (Ygdrasil). The life of the world is a struggle between the good and light gods on the one side, and the offspring of chaotic matter, the giants, nature’s disturbing forces, on the other. This struggle extends also into man’s being: the spirit proceeds from the gods, the body belongs to the world of the giants; they struggle with each other for the supremacy. If the spirit conquers by virtue and bravery, man goes to heaven after death, to fight in concert with the gods against the evil powers; but if the body conquers and links the spirit to itself by weakness and low desires, then man sinks after death to the world of the giants in the lower regions, and joins himself with the evil powers in the warfare against the gods.