شش خطی 51
تندر، شوک، زلزله (Zhen)

Thunder is movement, action, represented as thunder. In the body of the hexagram, one yang is born below two yins, symbolizing the presence of movement within stillness. Here two thunders combine: From this action you arrive at that action, from that action you produce this action—a thousand actions, myriad acts, are all this one action; therefore it is called thunder.

This hexagram represents acting so as to proceed on the Path, warily practicing introspection; it follows on the previous hexagram revolution. Revolution involves gaining joy through illumination, refining metal by fire, removing old impurities. Removing old impurities does not mean forgetting things, forgetting the body, extinguishing the mind, and stopping thoughts; it is necessary to remove impurities in the midst of action in order to accomplish the task. This is because the Tao is alive, in movement; it is neither material nor void. We use worldly realities to practice the reality of the Tao, and use human affairs to cultivate celestial virtues; both striving and nonstriving, comprehending essence and comprehending life, the endless work all must be done in the midst of activity. Therefore there is a path of development in thunder.

However, there is inner activity and outer activity. Inner activity means the movement of inward thoughts, outer activity means the activity of affairs that come up. Inner activity is in the realm of self, outer activity is in the realm of other. If inner activity is genuine, outward activity will also be genuine; if inner activity is artificial, outward activity will also be artificial. Superior people are careful about what they do not see, wary about what they do not hear; this means being careful and wary about inner activity. If there is no random activity within, there will naturally be genuine activity. The movement of genuine activity may go on all the time without causing any disturbance; using this to deal with external activity, one responds without minding. Therefore “when thunder comes, there is alarm, then laughter.”

The coming of thunder means that within stillness there is suddenly movement; alarm followed by laughter means initial carefulness and subsequent ease. One moment of goodness in people’s minds, and the mind of Tao appears; this is heaven. One moment of evil in the mind, and the human mentality acts; this is hell. Hell and heaven do exist in the world—they are both created in people’s minds. It is the good and evil, falsehood and truth of thoughts, which distinguish them.

When you have thoughts, if you can practice introspection, gradually eliminating bad thoughts and gradually producing good thoughts, after a long time of consistency thought after thought all return to correct orientation, so that the mind of Tao is ever-present, and the human mentality does not arise: Filled with living energy, the real self sits peacefully in the center, tranquil and unperturbed, yet sensitive and effective. Whatever comes up, you are cheerful and calm, responding with good humor, not minding at all—even if “thunder startles for a hundred miles,” still you “don’t lose spoon and wine.”

A spoon is for eating; wine represents fine drink. When thunder peals over a hundred miles, it is very loud, and can easily startle people. If you don’t lose your marbles when this happens, this means the vicissitudes of circumstance aren’t able to disturb your balance. Because superior people are wary of inner activity, they do not fear outward activity.

Being wary of inner activity means nurturing the energy; not fearing outward activity means not agitating the energy. If one can inwardly nurture energy and outwardly not agitate energy, acting when the time is for action, not acting when the time is for inaction, accompanying the “thunder,” going along with the time, myriad actions are all genuine activity—there is no impediment in action. Herein lies the developmental quality of thunder.

Thunder is movement. Above and below is thunder ; this represents the movement of the sound of thunder, traveling from here to there, from there to here. When the thunder here stops, thunder elsewhere erupts; thunder continuing upon thunder is the image of thunder.

What superior people see in this is that errant thoughts arise wildly, another thought arising before one thought is ended, thought after thought continuing, like the movement of traveling thunder, reverberating unceasing. So if people are unable to practice introspection, they will injure nature and reason, abandon the real and enter the false, ultimately destroying their own essential life.

Therefore superior people cautiously practice introspection, striving to cause true mindfulness to grow and errant thought to vanish, not allowing the slightest defect to remain in the heart. This is because good and evil, fortune and calamity, depend on the movement of a single thought, which makes the difference between heaven and hell. One can only sustain good thoughts and get rid of bad thoughts if one is able to be cautious before the movement of thought and introspective after the movement of thought, guarding against dangers, aware of perils, not daring to slack off at any time.

Sustaining good thoughts and getting rid of bad thoughts until all bad thought is gone and all thought is purely good, ultimately wholesome without any ill, then thought may be active all the time without one being hindered by its activity, that activity returning to the state of total integration with the celestial design.