The historic religions of heathenism have not preserved either the primitive dualistic monotheism, if the phrase may be permitted, or the simplicity of divine functions here sketched. With the advance of civilization the objects of worship must necessarily take upon them new responsibilities. If a tribe has its home by the sea, sooner or later it trusts frail barks to the waters, and to its gods is committed the charge of sea-faring. When handicrafts are invented, these also become their care. When the pressure of tribe upon tribe leads to war, they champion the host in battle. Moral ideas emerge and attach themselves to their service: and ultimately they become identified with the rulers of the dead, and reign in the shadowy world beyond the tomb. Another set of processes combine to produce what is known as polytheism. The constant application of fixed epithets to the godhead tends in the long run to break up its unity. Special aspects of it begin to take on an independent existence. Thus amongst the Teutonic peoples Tiwaz-Thunaraz, the thunderous sky, gives rise to Thunar or Thor, and Tiwaz-Frawiaz, the bounteous sky, to Freyr. And so the ancient heaven-god is replaced by distinct gods of rain and sunshine, who, with the mother-goddess, form that triad of divinities so prominent in several European cults[364]. Again as tribes come into contact with each other, there is a borrowing of religious conceptions, and the tribal deities are duplicated by others who are really the same in origin, but have different names. The mythological speculations of priests and bards cause further elaboration. The friendly national gods are contrasted with the dark hostile deities of foreign enemies. A belief in the culture-hero or semi-divine man, who wrests the gifts of civilization from the older gods, makes its appearance. Certain cults, such as that of Druidism, become the starting-point for even more philosophic conceptions. The personal predilection of an important worshipper or group of worshippers for this or that deity extends his vogue. The great event in the later history of Teutonic heathenism is the overshadowing of earlier cults by that of Odin or Wodan, who seems to have been originally a ruler of the dead, or perhaps a culture-hero, and not an elemental god at all[365]. The multiplicity of forms under which essentially the same divinity presents itself in history and in popular belief may be illustrated by the mother-goddess of the Teutons. As Freyja she is the female counterpart of Freyr; as Nerthus of Freyr’s northern doublet, Njordr. When Wodan largely absorbs the elemental functions, she becomes his wife, as Frîja or Frigg. Through her association with the heaven-gods, she is herself a heaven-as well as an earth-goddess[366], the Eostre of Bede[367], as well as the Erce of the Anglo-Saxon ploughing charm[368]. She is probably the Tanfana of Tacitus and the Nehellenia of the Romano-Germanic votive stones. If