The rise of Sumerian culture on the shores of the Persian Gulf is in accordance with Babylonian tradition. Babylonian myths told how Oannes or Ea, the god of culture, had risen each morning out of his palace in “the deep,” bringing with him the elements of civilization which he communicated to mankind. Letters, science and art had all been his gifts. He had instructed the wild tribes of the coast to build houses and erect temples; he had compiled for them the first law-book, and had instructed them in the mysteries of agriculture. Babylonian civilization was sea-born. The system of cosmology which finally won its way to acceptance with the priesthood and philosophers of Babylonia was one which had been first conceived at Eridu, the site of which is now more than a hundred miles distant from the sea, but in the early days of Babylonian history, before the silting up of the shore, had been its seaport. Here the first man Adam[70] was supposed to have lived, and to have spent his time fishing in the waters of the Gulf. The whole earth was believed to have grown out of a primeval deep like the mud-flats which the inhabitants of Eridu saw slowly emerging from the retreating sea. Philosophy and cosmology, with the theology with which they were associated, looked back upon Eridu and the Babylonian coast as their primeval home.[71] In fact the physical conditions of the Babylonian plain rendered it impossible for the first culture of the country to have sprung up in it. Before it was reclaimed by engineering skill and labour the larger part of it had been a pestiferous marsh. The science needed for making it habitable, at least by civilized man, must have arisen outside its boundaries. Only when he was already armed with a civilization which enabled him to dig canals, to mould bricks, and pile his houses and temples on artificial foundations could the Sumerian have settled in the Babylonian plain and there developed it still further. The cities of the plain grew up each round its sanctuary, which became a centre of civilization and progress, of agriculture and trade. But the builders of the sanctuaries must have brought their culture with them from elsewhere.