What is Zi Wei Dou Shu?

The name is built from Ziwei, the Purple Star, and doushu, the numbers of the Plough or Dipper. Stéphanie Homola, an anthropologist of Chinese divination, classes it with bazi as a form of calendar horoscopy, in which a person's fate is calculated from the moment of birth.

The chart is a ring of twelve palaces. Each palace stands for an area of life: self, siblings, spouse, children, wealth, health, travel, friends, career, property, fortune and parents.

Fourteen main stars are placed in those palaces, led by Ziwei and Tianfu. References count over one hundred named stars in all, including lesser ones. Their positions in a chart are worked out from the calendar, with no observation of the sky.

A chart needs the lunar month and day of birth, the birth hour and the year's stem and branch. The month and hour fix the life palace, the first of the twelve. The stem and branch of that palace give a number called the bureau, and the bureau and lunar day together place the star Ziwei. The other main stars follow from it.

The stem of the birth year then marks four stars with four transformations. Ten-year periods move through the palaces in a direction set by the year and the recorded sex of the person.

Modern practice has several schools. The Three-Conjunction approach looks at groups of stars and how palaces relate. The Flying Star approach follows the transformations from palace to palace, and is associated with modern Taiwan. The Zhongzhou school is strongest in Hong Kong and Macau. Many readers draw on more than one.

Three Ming items anchor the written history. The first is a preface to the Ziwei doushu quanshu (紫微斗數全書) signed by the scholar Luo Hongxian (1504 to 1564) and dated 1550. The surviving printed copies of that book are later than the preface, so the date needs care.

The second is the Ziwei doushu jielan, finished in 1581 and described as the earliest place the name Ziwei Doushu can be traced. It is reported to be the oldest surviving printed book on the subject, issued by a Nanjing bookseller.

The third is a three-chapter text titled Ziwei doushu that entered the Wanli supplement to the Daoist Canon, in 1607. Its list of stars and its way of laying out a chart differ from what is used today. It opens with a set of steps that begins by fixing the time and setting up the eight characters, the same starting point as bazi.

Later versions of the Ming books kept the method in circulation. The two most widely read texts are a late Qing woodblock reprint of the Ziwei doushu quanji and a lithograph of the Quanshu from the Republican era. Rules in those books do not always match common modern practice, and charts can differ depending on which is followed.

In the 1930s Wang Caishan published works on the method. Schools then formed across China, Hong Kong and Taiwan in the later twentieth century. Homola notes that it is highly popular in Taiwan today.

Tradition names Chen Tuan (陳摶), a Daoist of the 900s, as the founder, and a further legend has the immortal Lü Dongbin passing the art to him. Modern references say this cannot be verified historically. The Wikisource text from the Daoist Canon lists him as author only in its header, and its opening section does not mention him. One writer on the subject reports that no Song records link him to astrology at all.

The story that the method was once kept inside the imperial Bureau of Astronomy is repeated in modern writing, and we found no early document for it. The two chapters of the Qing imperial catalogue on fate calculation that we read do not list it. That absence is suggestive, though it does not settle the question.

Its roots are debated. Homola writes that Indian divinatory systems, carried by Buddhism, greatly influenced Chinese astrology, including this method. The scholar Ho Peng Yoke is reported to have proposed a link to an older divination form called taiyi, but we could confirm that only secondhand.

Whether the method existed in a recognizable form before the sixteenth century is unknown. Who first assembled it is unknown too.