Vain is the word of a philosopher that does not heal the suffering of humankind.
For just as there is no profit in medicine that does not expel diseases of the body, so there is no profit in philosophy either if it does not expel suffering of the heart and mind.
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.