数字卦和《周易》关系再探——以《左传》“龟,象也;筮,数也”为视角

The Relationship between Numerical Hexagrams and Zhouyi:As Viewed from Zuo zhuan’s Discussion of Turtle Oracle Images and Yarrow Numbers

“龟,象也;筮,数也”揭示出,从商代龟筮并行到周代筮之单行,周人之《周易》对龟卜之观象有所吸收,而对蓍筮有所改造。这个改造就是将数与象结合起来,形成阴阳爻画八卦。其改造过程是:数字卦最初以奇偶三三排列形成八卦,再两两组合,形成六位数卦,而其占筮却是通过上下卦的卦象和卦中数字占筮的。直到周人以“六峜合阴阳”,再融入■■,才形成阴阳爻画八卦与六十四卦,观象以占。周人的这个融合,既可以解释为什么最初没有阴阳爻画卦,也可以解释西周以降直到战国晚期龟卜式微的现象。

“Tortoise-shell divination is based on images;yarrow-stalk divination is grounded on numbers”discoursed in the Zuo zhuan(Zuo’s Commentary on the Springs and Autumns Annals)reveals that from the use of both the tortoise-shell and milfoil-stalk methods of divination in the Shang(1600-1046 BCE)dynasty to the sole use of the yarrow-stalk method of divination in the Zhou(1046-256 BCE)dynasty,the Zhou people in the Zhou Changes assimilated the images in the tortoise-shell method of divination and transformed the yarrow-stalk method of divination.This transformation is manifested in the combination of numbers and images by which the eight trigrams with yin-yang lines were invented.The transformation process is:the numerical trigrams were initially formed by three odd and/or even numbers,and then their doubling gave birth to numerical hexagrams,while its milfoil divination was conducted by the images of the upper and lower trigrams and the numbers in the hexagram.It was not until the Zhou dynasty that people combined the six methods with yin and yang,and then adopted yin(■)and yang(■)lines to form the eight trigrams and sixty-four hexagrams,by observing the images of which divination was established.This fusion of the Zhou people can not only explain why there were no yin and yang lines in the beginning,but also account for the decline of tortoise-shell method of divination from the Western Zhou dynasty to the late Warring States period(475-221 BCE).