The Chinese have generally been represented as developing in complete isolation from other peoples. This traditional conception, however, breaks down with more intimate knowledge. Dr. Laufer has demonstrated that Chinese civilization, too, is a complex structure due to the conflux of distinct cultural streams. As an originally inland people inhabiting the middle and lower course of the Yellow River, they gradually reached the coast and acquired the art of navigation through contact with Indo-Chinese seafarers. Acquaintance with the northern nomads of Turkish and Tungus stock led to the use of the horse, donkey and camel, as well as the practice of felt and rug weaving, possibly even to the adoption of furniture and the iron technique.[8] Most important of all, it appears that essentials of agriculture, cattle-raising, metallurgy and pottery, as well as less tangible features of civilization are common to ancient China and Babylonia, which forces us to the conclusion that both the Chinese and Babylonian cultures are ramifications from a common Asiatic sub-stratum. It would be idle to speculate as to the relative contributions of each center to this ancient cultural stock. The essential point is that the most ancient Asiatic civilizations of which we have any evidence already indicate close contact of peoples and the dispersal of cultural elements. Contact of peoples is thus an extraordinary promoter of cultural development. By the free exchange of arts and ideas among a group of formerly independent peoples, a superiority and complexity is rendered possible which without such diffusion would never have occurred. The part played in this process by the cruder populations must not be underestimated. They may contribute both actively and passively; actively, by transmitting knowledge independently acquired, as in the case of the felt technique the Chinese learned from the northern nomads; passively, by forming a lower caste on which the economic labors devolve and thus liberating their conquerors for an enlarged activity in the less utilitarian spheres of culture.