Epictetus

“ For example, if you are convinced at this moment that it is night, do not change your opinion, if that seems best to you, but abide by it and say that you ought to abide by your decisions! Do you not wish to make your beginning and your foundation firm, that is, to consider whether your decision is sound or unsound, and only after you have done that proceed to rear thereon the structure of your determination and your firm resolve? ”

“ Why, what is more important or more to your advantage than to be convinced that it is not sufficient for a man merely to have reached decisions, and to refuse to change? These are the sinews of madness, not health. ”

“ That one ought to be steadfast, and that the moral purpose is naturally free and not subject to compulsion, while everything else is liable to interference and compulsion, subject to others and not our own—some men, I say, fancy that whenever they have formed a judgement they ought to stand by it immovably. ”