The Lake
Appears in fourteen chapters
Where the image appears
The lake is the Joyous: gathered water, open surface, the youngest daughter. Its trigram, Tui, is the smiling lake, and its doubled form is 58 Tui - The Joyous, Lake:
Lakes resting one on the other:
The image of THE JOYOUS.
Thus the superior man joins with his friends
For discussion and practice.
The commentary supplies the image's secret: "A lake evaporates upward and thus gradually dries up; but when two lakes are joined they do not dry up so readily, for one replenishes the other." Joy, like knowledge, is a gathered depth that must be fed, and "True joy, therefore, rests on firmness and strength within, manifesting itself outwardly as yielding and gentle."
The lake's giving is by evaporation, quiet enrichment from below. In 41 Sun - Decrease, "The lake at the foot of the mountain evaporates. In this way it decreases to the benefit of the mountain, which is enriched by its moisture," and in 31 Hsien - Influence (Wooing) the mountain with a lake on its sunken summit "is stimulated by the moisture from the lake." But gathered water is also pressure. In 45 Ts'ui - Gathering Together (Massing), "If the water in the lake gathers until it rises above the earth, there is danger of a break-through," and in 43 Kuai - Break-through (Resoluteness) the danger peaks: "When the water of a lake has risen up to heaven, there is reason to fear a cloudburst."
The lake also teaches limitation and fate. In 60 Chieh - Limitation, "A lake is something limited. Water is inexhaustible. A lake can contain only a definite amount of the infinite quantity of water; this is its peculiarity." And the dried lake is Exhaustion itself, 47 K'un - Oppression (Exhaustion): "When the water has flowed out below, the lake must dry up and become exhausted. That is fate."
The Taoist note is joy that comes from gathered depth rather than surface excitement. The low-lying lake that receives all streams recalls Tao Te Ching 66, where the sea is lord of the hundred valleys because it knows how to lie below them; the joyous, like the sage, gathers because it is low.