Wind and Wood
Appears in fifteen chapters
Where the image appears
Wind and wood are one trigram, Sun, the Gentle, and one idea: gentle, ceaseless, invisible penetration. The wind slips through every crack; the root works its way around every stone; neither forces, and neither stops. The home hexagram is 57 Sun - The Gentle (The Penetrating, Wind):
Winds following one upon the other:
The image of THE GENTLY PENETRATING.
Thus the superior man
Spreads his commands abroad
And carries out his undertakings.
Its commentary states the law of the image: "The penetrating quality of the wind depends upon its ceaselessness. This is what makes it so powerful; time is its instrument." Effects won this way "are less striking to the eye than those won by surprise attack, but they are more enduring and more complete."
As wood, the same power works underground. In 46 Shêng - Pushing Upward, "Adapting itself to obstacles and bending around them, wood in the earth grows upward without haste and without rest." As wind, it works across the whole surface of the world: in 20 Kuan - Contemplation (View), "When the wind blows over the earth it goes far and wide, and the grass must bend to its power"; in 18 Ku - Work on what has been spoiled (Decay) the wind thrown back low on the mountain becomes the challenge to stir up what has stagnated; in 59 Huan - Dispersion (Dissolution) "The wind drives over the water" and dissolves the rigidity of frozen, selfish hearts.
The book is honest about the limits of gentleness. In 09 Hsiao Ch'u - The Taming Power of the Small the wind drives the clouds across heaven and makes them dense, "yet, being nothing but air, without solid body, it does not produce great or lasting effects." Restraint by gentleness is real but small; its successes are preparatory, won bit by bit. Wood in wind's service reaches from the well rope of hexagram 48 and the caldron's fuel of 50 to the slow tree of Development (53).
The Taoist parallel is Tao Te Ching 43: the softest thing in the world rides roughshod over the hardest, and the unsubstantial penetrates where there is no crevice. Influence by atmosphere rather than command is the Taoist ruler's whole method, and it is Sun's method too.