A man of profound virtue is like a newborn babe. Venomous insects will not sting him, snakes will not bite him, beasts will not harm him, and ferocious birds will not prey on him. He is by no means strong physically, but keeps his fists tightly clenched. Although he knows nothing about intercourse with a woman, his genital hardens because he is full of vital energy. He wails all day without getting hoarse because his energy is mellow. An appreciation of mellow energy promises an understanding of permanence. This, in turn, is akin to wisdom. Indulging in sensual pleasures and unscrupulously craving for life will incur misfortune. If vital energy is dictated by desire, that is an outrageous flaunt. Excessive strength marks the beginning of aging, for it goes against the way of nature. Any violation of this rule will lead to one’s fall. (Laozi)

He who is capable of retaining a childlike heart is a truly virtuous man. (Mencius)