古印度地轮-水轮-风轮-空轮说在中国

ANCIENT INDIAN THEORY OF EARTH-WHEEL, WATER-WHEEL, WIND-WHEEL AND EMPTY-WHEEL IN CHINA

印度古代关于一个小世界的结构的理论，至迟在西晋（265-317年）时期便已随佛教的东来传入中国。这一理论认为：大地（即地轮）浮在水体（即水轮）之上，水轮依托于风轮之上，而风轮则有广漠的虚空承托，于是各自得以不坠落，从而论述了天地结构的稳定性，也表述了大地乃是在虚空中之一物的观念。从西晋到唐代（约7世纪）至少有5部佛经提及地轮、水轮、风轮的各不相同的具体尺度，这说明这一理论在古代印度有不同的流派存在。这一理论在佛教信徒中广为流传当无疑问。它也为一些道士所接受，并被改造成易为中国人理解的观念，载于若干道家的经典中。由于这一理论同占主导地位的张衡浑天说存在较大差异，又由于有关佛经对这一理论的具体描述各异而造成的混乱，致使这一理论在较长时间内并未产生更大的影响。一直到五代时期（约10世纪），这一理论的基本思想才得到重视，并成为对张衡浑天说进行重大改造的推动力。

The anclent lndian theory about the structure of a small world had been introduced into China in Western Jin (265-317) at the latest. This theory holds that the earth (earth wheel) floats on a water body (water wheel), the water wheel resides in a wind wheel, and the wind-wheel in supported by the immense void, so each of them does not drop or fall down. In this way it proves the stability of structure of the heaven and the earth, and also expresses the idea that the earth is one of the objects in the void. From Western Jin to Tang (ca. 7th century) at least 5 Buddhist classics mentioned different scales of earth wheel, water wheel and wind wheel, which shows that the theory had different schools in anclent India. No doubt the theory spread among Buddhists. It was also accepted by some Taoists and remolded into ideas which were easily understood by Chinese, and was written in some Taoist classics.Because the theory differs considerably from the dominant Hun Tian Theory set out by Zhang Heng, and also the descriptions of the theory differ in different Buddhist classics, it had not had great effect for a long time. It was not until the Five Dynasties that attention was paid to the basic idea of the theory, which became a driving force to important reformation of Zhang Heng's Hun Tian Theory.