Is the principle of loyalty and filial piety in my mind, or in the ruler and parent?
"Is the principle of loyalty in my mind, or in the ruler?"
爱问：「至善只求诸心，恐于天下事理有不能尽。」
先生曰：「心即理也。天下又有心外之事、心外之理乎？且如事父，非于父而求孝之理矣；事君，非于君而求忠之理矣。以此心之条理而言，谓之理。忠与孝之理，在吾心邪？在父与君邪？使在父与君，父没君薨之后，吾心遂无忠孝之理邪？」
Xu Ai asked: "If the supreme good is sought only in the mind, I fear it may not exhaust all the principles of affairs in the world."
The Master said: "The mind is principle. How can there be affairs or principles outside the mind? Take serving one's father — one does not seek the principle of filial piety from the father. Serving one's ruler — one does not seek the principle of loyalty from the ruler. Speaking of this mind's orderliness, it is called principle. Is the principle of loyalty and filial piety in my mind, or in the father and ruler? If it were in the father and ruler, then after the father passes and the ruler dies, would my mind have no more principles of loyalty and filial piety?"
Your moral judgment does not depend on external authority. Even without laws or social norms, you still know what is right deep inside. Yangming's thought experiment reminds us: the root of morality is inside, not outside.
"The mind is principle. How can there be affairs or principles outside the mind?"
Yangming repeats the fundamental proposition with a concrete thought experiment: if the principle of loyalty lies in the ruler (external), then after the ruler dies, would your mind have no more principle of loyalty? Obviously not — the principle of loyalty is in the mind, not in the external object.
"Speaking of this mind's orderliness, it is called principle."
"Principle" is not an external law but the mind's orderliness — the natural order and norms that the mind naturally presents in different situations. Facing your father is filial piety, facing your ruler is loyalty, facing your friends is trustworthiness — these are all the natural orderliness of the same mind in different relationships.