盡其心者知其性也
He Who Fully Develops His Heart Knows His Nature
孟子曰:"盡其心者,知其性也。知其性,則知天矣。存其心,養其性,所以事天也。殀壽不貳,修身以俟之,所以立命也。"
Mencius said: “He who fully develops his heart knows his nature. Knowing his nature, he knows heaven. To preserve one’s heart and nourish one’s nature is the way to serve heaven. Whether life is short or long, to not waver but cultivate oneself and await one’s fate — this is how to establish one’s destiny.”
Notes
This opening line gives the chapter its name. It establishes the chain: fully developing the heart (盡心) → knowing human nature (知性) → knowing heaven (知天). This is the metaphysical foundation of Mencian thought.
