Principle 01
The Four Sprouts 四端
「恻隐之心,仁之端也;羞恶之心,义之端也;辞让之心,礼之端也;是非之心,智之端也。人之有是四端也,犹其有四体也。」Compassion, shame, deference, discernment — the sprouts of benevolence, righteousness, ritual, wisdom — are as universal as four limbs. The mechanism is extension (扩充): every person already feels compassion in some case — the child at the well — and the work is to extend that response to all cases. 「苟不充之,不足以事父母」— unfilled out, the sprouts cannot even serve one's parents. The moral material is given; the failure mode is always neglect, never absence.
Principle 02
Seek Within Yourself 反求诸己
「爱人不亲,反其仁;治人不治,反其智;礼人不答,反其敬。行有不得者,皆反求诸己。」Love that meets no closeness, governance that meets no order, courtesy that meets no answer — in each case, inspect your own sincerity, skill, and respect. The mechanism is control-variable analysis: the only variable you command is your own input, so that is where the diagnostic runs. The payoff compounds: 「其身正,而天下归之」— when the self is rectified, the world gravitates to it. Blaming outward skips the only fix that is available.
Principle 03
Noble, Righteous Qi 浩然之气
「其为气也,至大至刚,以直养而无害,则塞于天地之间。」Mencius's noble, righteous qi is moral courage as a stock variable: 「是集义所生者,非义袭而取之也」— it is generated by accumulated right action, not seized by a single heroic act. Every small right deed deposits; any act of self-betrayal withdraws — 「行有不慊于心,则馁矣」, one deed that leaves the heart ashamed and the whole store collapses. The mechanism rules out both shortcuts and cover-ups: the stock cannot be faked, because it is audited from inside.
Principle 04
Never Force the Growth 勿助长
A man of Song pulled up his seedlings to help them grow and went home boasting of his work; the seedlings were dead. 「天下之不助苗长者寡矣」— few indeed avoid forcing. Mencius names the two failure modes of cultivation: abandoning the field as hopeless (不耘苗者, the non-weeder) and forcing the pace (揠苗者, the puller). The prescription is 「必有事焉而勿正,心勿忘,勿助长也」— keep steadily at the work, without fixating on the outcome, without forgetting, without forcing. Growth has an internal clock; the cultivator's art is tending, not acceleration.