Upper & Lower Trigrams

Upper and lower trigrams determine how six lines form a hexagram. Inner and outer organize its positions. Traditional imagery may use them for inside/outside, near/far or sequence, depending on the method and subject; upper is not automatically future and lower automatically past.

Count upward: lines one to three form the lower or inner trigram; four to six form the upper or outer. Identify each three-line group independently. Line recording starts below, but descriptive names such as Water over Fire place the upper imagery first.

Hexagram 63, After Completion (Ji Ji), has Li (Fire) below and Kan (Water) above. Hexagram 64, Before Completion (Wei Ji), has Kan (Water) below and Li (Fire) above. Swapping positions changes the structure even when the two images are the same.

Changing only Qian’s bottom line changes the lower trigram to Xun while upper Qian stays, producing Gou, Heaven over Wind. Changing only the top line turns upper Qian into Dui while lower Qian stays, producing Guai, Lake over Heaven. One changed line in a different group yields a different hexagram.

A chart displayed top-to-bottom still places line six at the top; it is not the first cast. Establish line order before splitting trigrams or interpreting change positions.