Lactantius

“ For every one, when he hears another giving precepts, is unwilling that the necessity of obeying should be imposed upon him, as though the right of liberty were taken from him. Therefore he answers his teacher in this manner: I am not able to do the things which you command, for they are impossible. ”

“ Or if you are so entirely of opinion that it is possible to resist nature, do you yourself practice the things which you enjoin, that I may know that they are possible? But since you yourself do not practice them, what arrogance is it, to wish to impose upon a free man laws which you yourself do not obey! ”

“ What, therefore, will that instructor do, if these things shall be objected to him? how will he deprive the self-willed [2] of an excuse, unless he teach them by deeds before their eyes [3] that he teaches things which are possible? Whence it comes to pass, that no one obeys the precepts of the philosophers. [4] For men prefer examples rather than words, because it is easy to speak, but difficult to accomplish. [5] Would to heaven that there were as many who acted well as there are who speak well! But they who give precepts, without carrying them out into action, are distrusted ”