Apart from these more or less political speculations, there came into existence in this period, by no mere chance, a school of thought which never succeeded in fully developing in China, concerned with natural science and comparable with the Greek natural philosophy. We have already several times pointed to parallels between Chinese and Indian thoughts. Such similarities may be the result of mere coincidence. But recent findings in Central Asia indicate that direct connections between India, Persia, and China may have started at a time much earlier than we had formerly thought. Sogdian merchants who later played a great role in commercial contacts might have been active already from 350 or 400 B.C. on and might have been the transmitters of new ideas. The most important philosopher of this school was Tsou Yen (flourished between 320 and 295 B.C.); he, as so many other Chinese philosophers of this time, was a native of Shantung, and the ports of the Shantung coast may well have been ports of entrance of new ideas from Western Asia as were the roads through the Turkestan basin into Western China. Tsou Yen’s basic ideas had their root in earlier Chinese speculations: the doctrine that all that exists is to be explained by the positive, creative, or the negative, passive action (Yang and Yin) of the five elements, wood, fire, earth, metal, and water (Wu hsing). But Tsou Yen also considered the form of the world, and was the first to put forward the theory that the world consists not of a single continent with China in the middle of it, but of nine continents. The names of these continents sound like Indian names, and his idea of a central world-mountain may well have come from India. The “scholars”