'Know, that not easily shall a conviction arise in a man unless he every day speak the same things and hear the same things, and at the same time apply them unto life.
Every great power is perilous to beginners. Thou must bear such things according to thy strength. But must I live according to Nature? That is not for a sick man. Lead thy life as a sick man for a while, so that thou mayest hereafter live it as a whole man. Fast, drink water, abstain for a while from pursuit of every kind, in order that thou mayest pursue as Reason bids. And if Reason bids, then when thou shalt have aught of good in thee, thy pursuit shall be well. Nay, but we would live as sages and do good to men. What good? What will thou do? Hast thou done good to thyself? But thou would'st exhort them? And hast thou exhorted thyself? Thou would'st do them good - then no manner of men philosophy can make. In thy eating do good to those that eat with thee, in thy drinking to those that drink, by yielding and giving place to all, and bearing with them. Thus do them good, and not by spitting thy bile upon them.'
-- Epictetus, To The Learner