Some are born with knowledge, some derive it from study, and some acquire it only after a painful realization of their ignorance. But the knowledge being possessed, it comes to the same thing. Some study with a natural ease, some from a desire for advantages, and some by strenuous effort. But the achievement being made, it comes to the same thing.
By three methods we may learn wisdom: First, by reflection, which is noblest; Second, by imitation, which is easiest; and third by experience, which is the bitterest.
There are three things which the superior man guards against. In youth ... lust. When he is strong ... quarrelsomeness. When he is old ... covetousness.
Study the past if you would define the future. I am not one who was born in the possession of knowledge; I am one who is fond of antiquity, and earnest in seeking it there. Learning without thought is labor lost; thought without learning is perilous.