说“元二”——兼论数术背景下的汉代历法

The Meaning of"Yuan er"and Han Calendars in the Context of the Divination

《后汉书》、汉碑有"元二之灾""中遭元二"等说法,其"元二"长久以来不得确解。实则"元二"的说法,与数术背景下汉代的历法有关。汉代阴阳谶纬学说盛行,当时历家推定历法,也受到阴阳家思想观念的影响。汉人"以律起历",历家又迷信特殊数字,以《易》数来算律历,并以律历谈灾异。西汉前期官方实行《颛顼历》,武帝元封七年改行《太初历》,两者有所龃龉,历家为了弥合两者矛盾,于是在新历的一元中加入阴、阳二种灾岁,阳旱阴水,即一元之中有水、旱二种灾害,是为"元二之灾"。

The meaning of"yuan er"in the History of the Eastern Han and some steles of Han dynasty is unknown through the ages.As a matter of fact,this term was created due to the various Han calendars against the divinatory background.In the Han dynasty when the thought ofYin-yang and divination studies were flourishing,calendars were made based on not only astronomical observation but also divinatory thoughts.Moreover,because of the canonization of the Book of Changes and the warship of some mysterious figures,scholars employed numbers of the Book of Changes to explain calendric numbers and try to forecast natural disasters.In the early Western Han period,the Zhuanxu Calendar was the official calendar.While in 104 BC,the Han government started to use Taichu Calendar.There were some contradictories between these two calendars,so 57 disastrous years were inserted into the new calendar to reconcile the gap between these two calendars.And it was claimed that there were two kinds of disasters,flood and drought.Therefore,in this new calendric system,there were two kinds of disasters in one yuan(a time cycle of about 4617 years).This is the correct meaning of "yuan er".