" IN our tales concerning the beginning of things three great goddesses play the part of Mother of the World: the sea-goddess Tethys, the goddess Night, and Mother Earth. They constitute a Trinity; but this may well be a chance result of the fact that only three tales of such a Mother have come down to us. It may also be a result of chance that in the tale concerning the origin of the Trojan War, the most important event in the age of our heroes, three goddesses appear in the story of the Judgment of Paris. All through our mythology one comes across three goddesses. What is more, they do not merely form accidental groups of three—usually a group of three sisters—but actually are real trinities, sometimes almost forming a single Threefold Goddess. Tales are also told of larger groups, of fifty goddesses or fifty daughters of the same father or couple. Let me at once state the association suggested by these numbers. Our lunar month was divided into three parts, and our moon had three aspects: as the waxing, the full and the waning sign of a divine presence in the sky. "
― Karl Kerényi , The Gods of the Greeks