That there had been spirits of the sky, however, as well as spirits of the earth, was never forgotten. By the side of the Anunna-ki or "spirits of the earth" the later theology continued to retain a memory of the Igigi or spirits of heaven.(243) As En-lil was the chief among the spirits of the earth, so it is probable that Ana was chief among the spirits of the sky. But there was not the same difficulty in accommodating his name and personality to the new conception of a god that there was in the case of En-lil. His old Sumerian title brought with it no associations with animism; there was no need to change it, and it could therefore, like the name of Ea, be retained even when the spirit of the sky had become the god of heaven. From the outset Ana had stood outside the sphere and dominion of En-lil; he was no ghost of the underworld to be degraded or renamed.
While, therefore, in En-lil of Nippur, even under his new Semitic form of Bel, the dominant element remained Sumerian, and in Ea of Eridu the Semitic and Sumerian elements were mingled together, Ana of Erech was distinctively a Semitic god. It was only by main force, as it were, that En-lil could be transformed into the semblance of a Semitic Baal; up to the last he continued to be lord of the earth rather than of the sky, whose dwelling-place was below rather than above.(244) It was this, perhaps, which facilitated his effacement by Merodach; the lineaments of a Baal were more easily traceable in the sun-god of Babylon than in the god of Nippur. But the sky-god was already a Baal. Between him and the Semitic Baal-shamain, "the lord of heaven," the distance was but slight, and it was not difficult to clothe him with the attributes which the Semite ascribed to his supreme deity. A consciousness of the fact may possibly be detected in the readiness with which the name and worship of Anu were accepted in the Semitic West; when Babylonian culture made its way to Canaan, it was primarily Anu and the divinities most closely associated with him--Istar, Anat, and Dagon--who found there a home.
Ana, the sky, thus became Anu, the god of a Semitised Babylonia. But a Semitised Babylonia could not conceive of a god without a goddess who stood to him in the relation of the feminine to the masculine gender. Out of Anu was formed Anat, the feminine counterpart of the god. The same process at Nippur had created a Belit or Beltis out of the masculine Bel. The goddesses owed their existence to a grammatical necessity, and their unsubstantial and colourless character justified their origin. They fitly represented the relation in which, according to Semitic ideas, the woman stood to the man. She was formed out of him in nature as the feminine was out of the masculine in language, and her very existence thus depended on her "lord."