星占对中国古代战争的影响──以北魏后秦之柴壁战役为例

北魏道武帝天兴五年（公元４０２年），当北魏在柴壁打败后秦部队时，太史令晁崇上奏“月晕左角”的天象，并预言带角的动物将暴死。稍后，竞如晁崇所料，发生大疫，部队的数百头牛只，同日皆死于路旁。根据推算，当时绝无发生月晕左角的可能，再就事件中的人物加以分析，竞发现牛疫的发生似乎带有强烈的人为因素，而天象是被当做影响军事决策的工具。此事件突显中国古代天文与军事的密切关系，因此该文希望藉此个案，讨论中国古代星占对战争的影响。

THE INFLUENCE OF ASTROLOGY ON WARS IN ANCIENT CHINA:USING THE WAR OF 402 AT ZHAIBI AS AN EXAMPLE

After the Wei Empire defeated the Qin Empire at Zhaibi in 402, royal astrologer CHAO Chong foresaw the day when all animals with horns would die for unknownreasons, basing the grisly prediction on what he said to be his observation of the phenomenon,known as "the occurrence of lunar halo around f Virgo". An epidemic did break out. Hundredsof cattle raised by the troops died on the same day. But our calculation indicates the celestialphenomenon could not possibly occur at that time. The discovery, together with an analysisof the characters,leads to a reasonable conclusion that the "epidemic"was motivated by ill willwhile astrology was merely regarded as an instrument in formulating military strategies. Theabove case shows the possible impact of ancient Chinese astronomy on wars. Moreover, we tryto discuss the interaction between astrology and military affairs from the viewpoint of socialhistory of astronomy. Through this study, we want not only to explore the ignored aspects ofmilitary history, but also to shed some light on areas of traditional history.