ch’ien k’un, in traditional Chinese cosmology, the names of the two most important trigrams in the system of I-Ching (the Book of Changes). Ch’ien (S) is composed of three undivided lines, the symbol of yang, and k’un (S S) three divided lines, the symbol of yin. Ch’ien means Heaven, the father, creativity; k’un means Earth, the mother, endurance. The two are complementary; they work together to form the whole cosmic order. In the system of I-Ching, there are eight trigrams, the doubling up of two trigrams forms a hexagram, and there are a total of sixtyfour hexagrams. The first two hexagrams are also named ch’ien (SS) and k’un (S SS S). See also T’AI- CH. S.-h.L.