Upon the question of the distribution of land and water, unanimity no longer prevailed. By some it was maintained that there was one ocean, confluent over the whole globe, so that the body of known lands, that so-called continent, was in truth an island, and whatever other inhabitable regions might exist were in like manner surrounded and so separated by vast expanses of untraversed waves. Such was the view, scarcely more than a survival of the ocean-river of the poets deprived of its further bank by the assumption of the sphericity of the earth, held by Aristotle,[277] Crates of Mallus, Strabo, Pliny, and many others. If this be called the oceanic theory, we may speak of its opposite as the continental: according to this view, the existing land so far exceeded the water in extent that it formed in truth the continent, holding the seas quite separate within its hollows. The origin of the theory is obscure, even though we recall that Homer’s ocean was itself contained. It was strikingly presented by Plato in the _Phaedo_, and is implied in the Atlantis myth; it may be recalled, too, that Herodotus, often depicted as a monster of credulity, had broken the bondage of the ocean-river, because he could not satisfy himself of the existence of the ocean in the east or north; and while reluctantly admitting that Africa was surrounded by water, considered Gaul to extend indefinitely westward.[278] Hipparchus revived the doctrine, teaching that Africa divided the Indian Ocean from the Atlantic in the south, so that these seas lay in separate basins. The existence of an equatorial branch of the ocean, a favorite dogma of the other school, was also denied by Polybius, Posidonius, and Geminus.[279] The reports of traders and explorers led Marinus to a like conclusion; both he and Ptolemy, misinterpreting their information, believed that the eastern coast of Asia ran south instead of north, and they united it with the eastern trend of Africa, supposing at the same time that the two continents met also in the west.[280] The continental theory, despite its famous disciples, made no headway at Rome, and was consequently hardly known to the Middle Ages before its falsity was proved by the circumnavigation of Africa.[281]