But there is an old proverb that "there is no smoke without fire." The war of Troy or the beleaguerment of Thebes may be but a repetition of the time-worn story of the battle waged by the bright powers of day round the battlements of heaven; but there must have been some reason why this story should have been specially localized in the Troad and at Thebes. Most of the Greek myths have a background in space and time; and for this background there must be some historical cause. The cause, however, if it is to be discovered at all, must be discovered by means of those evidences which will alone satisfy the critical historian. The localization of a myth is merely an indication or sign-post pointing out the direction in which he is to look for his facts. If Greek warriors had never fought in the plains of Troy, we may be pretty sure that the poems of Homer would not have brought Akhilles and Agamemnon under the walls of Ilium. If Phoenician traders had exercised no influence on primaeval Greece, Greek legend would have contained no references to them. But even the myth itself, when rightly questioned, may be made to yield some of the facts upon which the conclusions of the historian are based. We now know fairly well what ideas, usages, and proper names have an Aryan stamp upon them, and what, on the other hand, belong rather to the Semitic world. Now there is a certain portion of Greek mythology which bears but little relationship to the mythology of the kindred Aryan tribes, while it connects itself very closely with the beliefs and practices of the Semitic race. Human sacrifice is very possibly one of these, and it is noticeable that two at least of the legends which speak of human sacrifice--those of Athamas and Busiris--are associated, the one with the Phoenicians of Thebes, the other with the Phoenicians of the Egyptian Delta. The whole cycle of myths grouped about the name of Herakles points as clearly to a Semitic source as does the myth of Aphrodite and Adonis; and the extravagant lamentations that accompanied the worship of the Akhaean Demeter (Herod. v. 61) come as certainly from the East as the olive, the pomegranate, and the myrtle, the sacred symbols of Athena, of Hera, and of Aphrodite.[24]