The disease of the soul is both more common and more deadly than the disease of the body. Just as medicine is the art devoted to healing the body, so philosophy is the art devoted to healing the soul, curing it of improper emotions, false beliefs, and faulty judgments, which are the causes of so much hardship and handicap. To heal the body one turns to the practitioner of the art of healing the body, but to heal the soul there is no doctor to turn to, and each of us is left to become that doctor unto himself. Yet, this need not stop us from exhorting others to imitate us in the godly art, in the forlorn hope that they might transform themselves into better citizens for Athens and better companions for us.
Neel Burton, Plato: Letters to my Son