THE SIGN:

Trigram Tui, the Joyousabove Tui the Joyous, Lake
Trigram Kên, Keeping Stillbelow Kên Keeping Still, Mountain

The name of the hexagram means "universal," "general," and in a figurative sense "to influence," "to stimulate." The upper trigram is Tui, the Joyous; the lower is Kên, Keeping still. By its persistent, quiet influence, the lower, rigid trigram stimulates the upper, weak trigram, which responds to this stimulation cheerfully and joyously. Kên, the lower trigram, is the youngest son; the upper, Tui, is the youngest daughter. Thus the universal mutual attraction between the sexes is represented. In courtship, the masculine principle must seize the initiative and place itself below the feminine principle.
Just as the first part of book 1 begins with the hexagrams of heaven and earth, the foundations of all that exists, the second part begins with the hexagrams of courtship and marriage, the foundations of all social relationships.