Duration
The Enduring Course
What lasts is not stillness but a direction held long enough to renew itself; rigidity is not constancy.
Heng places Zhen, the arousing, thunder, above Xun, the gentle, wind, forces that in the old reading always accompany each other. Zhen is the eldest son and Xun the eldest daughter, so where hexagram 31 shows courtship, this shows the settled relation of marriage. Duration is not understood as rest or immobility; it is movement held to a constant direction, a cycle that renews itself and therefore does not exhaust itself. The Image has the superior man stand firm and not change his direction, and the Judgement adds that it furthers one to have somewhere to go.
Light
Stands for constancy, settled relations and enduring institutions, and for holding a fixed direction long enough that the course renews itself rather than running down.
Shadow
The lines fault both haste and rigidity: seeking duration too soon brings misfortune, and so does making restlessness a permanent condition. Persisting in what ought to change is not constancy.
