Man is the measure of all things. The unexamined life is not worth living. Wonder is the feeling of a philosopher, and philosophy begins in wonder. All men by nature desire to know. We cannot learn without pain.
Man is by nature a political animal.
So the good has been well explained as that at which all things aim. A point is that which has no part. Virtue is its own reward. There is nothing permanent except change. He who has calmly reconciled his life to fate, and set proud death beneath his feet, can look fortune in the face, unbending both to good and bad.