兌

王弼以為兌卦的核心在「剛中柔外」——內有剛實之德，外現柔和之悅。如此的悅才能久。讀此卦最該記住「利貞」二字——悅必以正，無正則悅而不久。

Wang Bi takes the core of Dui to be 'firm within, soft without' (gang zhong rou wai 剛中柔外) — solid virtue inside, gentle pleasure showing outside. Only such joy can last. The two characters most worth remembering here are li zhen 利貞: joy must rest on correctness, and without correctness a joy does not endure.

兌是悅。彖傳點出骨架「剛中而柔外」：裡頭有實在的東西，外面纔悅得起來，也纔悅得長久。爻上分真偽：初九「和兌，吉」，九二「孚兌，吉」，和氣而悅、有信而悅，都立得住；六三「來兌，凶」就翻了面，自己空著，四處湊上去討人家給的高興，討來的終究留不住。大象給的路子是「君子以朋友講習」，同道切磋講論，悅從裡面生出來，這種高興有根。如今各路餵到眼前的熱鬧刺激，多半走的是來兌一路，看時興奮，看完更空。辨一個悅的真偽，就看它從自己心裡長出來，還是從外頭遞過來。

Dui is joy. The Tuan commentary names the skeleton: 'firm within, soft without.' There has to be something real inside before the outside can be pleasant — and before the pleasure can last. The lines sort real joy from fake. Line 1, 'harmonious joy, auspicious,' and line 2, 'sincere joy, auspicious' — joy from good temper, joy from good faith — both stand on their own. Line 3, 'joy that comes courting, ominous,' flips it: empty inside, going around soliciting happiness that others hand over, and what is begged never stays. The Great Image gives the practice: 'the superior man joins with friends in discussion and practice' — joy that grows from working through things with people on the same path has roots. Most of the stimulation now fed to our eyes runs on the line-3 pattern: exciting while you watch, emptier when it ends. To test whether a joy is real, ask whether it grew from your own heart or was passed to you from outside.