知人者智.自知者明.胜人者力.自胜者强.
战国•老子《道德经》
The one who knows well about others is only a smart guy, whereas the one who understands himself is the sensible Solomon.
The one who could defeat others is just a strong man, whereas the one who could win over his evil in mind (心魔) himself is really a powerful one.
Quoted from the work as Tao Te Ching (或意译:Canon of Morality) by Lao-tse (或:Laozi、Li Er,
李耳) during the Warring States period in ancient China