天干五合

Stem five harmonies (天干五合) are the five pairs the ten heavenly stems form: 甲己, 乙庚, 丙辛, 丁壬 and 戊癸, each with an element it is said to transform to. Where the same pairing occurs between stems hidden inside branches rather than revealed ones, this site treats it separately, under hidden harmony (暗合).

Ziping Zhenquan's chapter on stems that combine yet do not combine (《子平真诠·论十干合而不合》) exists to make a single point: the presence of a pairing and the effectiveness of a combination are separate questions. It separates two ways a combination fails. One is obstruction — with a 庚 standing between a 甲 and a 己, the intervening controlling stem obstructs the 甲, and the chapter treats this as a combination that dares not combine, present in name only. The other is distance: a 甲 in the year stem and a 己 in the hour are described as being of one mind but far apart, a half-combination whose effect the chapter puts at two or three parts in ten.

The chapter then limits the doctrine further. Some combinations do no harm at all, as when one of two revealed officers is combined away and one is left. A combination made by the day stem itself joins the Day Master to what belongs to it. Where two stems contend for one the chapter allows the affection to be divided rather than destroyed, and notes that separation removes the contention.

Worked example. In the example chart below the 乙 sits in the year stem and the 庚 in the hour, with two stems between them: by the chapter's account a distant pairing whose effect is put at two or three parts in ten.

Worked example (solar 1975-02-11 16:00, female):

This chart's pattern is 七杀格; the day master is 极弱.