恆Heng.Duration.
Thunder moves above Wind: movement and responsiveness form a recurring rhythm. Heng concerns continuity that remains alive—principles stable enough to endure and methods flexible enough to renew themselves.
Build continuity that can survive change.
Heng means endurance, constancy and long continuance. Thunder activates while Wind penetrates and adapts; together they create movement that can recur without losing orientation.
After the attraction of Xian, Heng asks what can be sustained. Commitment depends neither on momentary intensity nor mechanical repetition, but on returning to a correct way through changing circumstances.
The question is what should remain constant—and what must change so that the essential direction can continue.
Thunder above. Wind below.
Wind works continuously from within while Thunder moves outward. Endurance joins gradual penetration with timely action.
Choose the way. Keep it correct. Renew the cycle. Continue with purpose.
Constancy succeeds when it is attached to a worthy direction. Persistence in what is wrong merely makes error durable.
Continue beyond mood
Build rhythm that does not depend on novelty or emotional intensity.
Remain constant in what is right
Endurance has value only when its direction remains correct.
Let each ending renew the beginning
Durable systems cycle, review and begin again.
Hold your orientation
Adapt tactics without abandoning the governing principle.
Image principle: Thunder and Wind form Duration. The cultivated person stands firmly and does not change direction.
What endures does so through rhythm, correctness and renewal.
The governing proposition
恆：亨，無咎，利貞，利有攸往。
Duration. Success, no blame. Correctness is beneficial. It is beneficial to have somewhere to go.
Continuity needs both a stable principle and purposeful movement.
Long continuance in the way
恆，久也。剛上而柔下，雷風相與，巽而動，剛柔皆應，恆。恆亨無咎，利貞；久於其道也。利有攸往，終則有始也。
Heng means duration. Thunder and Wind work together; firm and yielding respond. Success comes from long continuance in the correct way.
End becomes beginning: the sun, moon and seasons endure through ordered change.
Stand without changing direction
雷風，恆；君子以立不易方。
Thunder and Wind: Duration. The cultivated person stands firmly and does not change direction.
Stable orientation allows continual adjustment without loss of identity.
Six errors and disciplines of endurance.
The lines distinguish premature depth, centred continuity, inconsistent character, persistence in the wrong place, fixed roles and restless instability.
Digging too deeply for durationDemanding permanence at the beginning brings misfortune · Changes to 34 大壯
初六：浚恆，貞凶，無攸利。
Do not demand deep commitment before foundations exist. Forcing permanence too early damages what might have grown naturally.
小象傳 · 浚恆之凶，始求深也。The misfortune comes from seeking depth at the beginning.
Regret disappearsCentred continuity corrects imbalance · Changes to 62 小過
九二：悔亡。
Stay centred rather than proving endurance through excess. Balanced persistence allows regret to dissolve.
小象傳 · 九二悔亡，能久中也。Regret disappears because one can remain long in the centre.
Character without constancyInconsistency attracts humiliation · Changes to 40 解
九三：不恆其德，或承之羞，貞吝。
When principles change with convenience, trust has nowhere to settle. Persistence in inconsistency only compounds regret.
小象傳 · 不恆其德，無所容也.Without constancy in character, there is no place that can accommodate one.
No game in the fieldLong persistence in the wrong place yields nothing · Changes to 46 升
九四：田無禽。
Effort cannot produce what the field does not contain. Review position and method instead of praising persistence for its own sake.
小象傳 · 久非其位，安得禽也？How can game be found by remaining long in the wrong position?
Constant in one roleFidelity may suit one position but trap another · Changes to 28 大過
六五：恆其德，貞，婦人吉，夫子凶。
Constancy must match responsibility. Fidelity to one relationship can be virtuous; leaders who merely follow a fixed role abandon judgment.
小象傳 · 婦人貞吉，從一而終也；夫子制義，從婦凶也。One role follows a single commitment; another must determine what is right.
Agitated durationRestless persistence accomplishes nothing · Changes to 50 鼎
上六：振恆，凶。
Constant motion is not constancy. When agitation occupies the highest position, continuity loses direction and produces no lasting work.
小象傳 · 振恆在上，大無功也.Agitated duration above is greatly without accomplishment.
Design continuity around principles, cycles and review.
Work and leadership
Use Heng when initiatives must survive beyond launch energy.
- Define the principle that cannot be traded.
- Build repeatable review and renewal cycles.
- Leave fields that cannot yield the intended result.
Relationships
Commitment develops through consistent conduct rather than premature demands.
- Let trust deepen in sequence.
- Keep promises stable while roles evolve.
- Do not confuse restlessness with growth.
Timing and decisions
Ask whether persistence remains correctly placed.
- Continue what compounds value.
- Change the method when the field is wrong.
- Turn completion into the next sound beginning.
Heng is constructive when stable direction and adaptive renewal reinforce each other.
Aligned expression
- Principles remain stable across changing conditions.
- Commitment deepens at an appropriate pace.
- Practice is reviewed and renewed.
- Persistence remains correctly placed.
Distorted expression
- Permanence is demanded prematurely.
- Repetition replaces learning.
- Inconsistency damages trust.
- Restless activity masquerades as commitment.