I Ching
Interpreted by wu wei

The Rulers of The Kua

There are two kinds of rulers: governing and constituting. The governing ruler is generally good and virtuous and is ruler by virtue of position and time. Line 5 is usually the governing ruler but sometimes another line is the ruler because of the time and the situation. The constituting ruler is the line that gives the kua its meaning. When the governing ruler and the constituting ruler are the same, there is only one ruler, and he is always of good character and holds his position because it is the correct position for him at that time. When the governing ruler and the constituting rulers are different, there are two rulers. In each kua, the governing ruler is indicated by a circle and the constituting ruler by a square. When they are the same, only a circle is used.
Keep in mind that all of the above comments reflect the general rule, but can be modified within a particular kua. The modification will always be clearly indicated. An example of a constituting ruler giving meaning to a kua can be seen in kua 9, Hsiao Ch’. The Restraining Power of the Small. The fourth line, the constituing ruler, represents the weak force that is restraining the other strong lines. The governing ruler of the kua is the strong undivided line in the fifth place.