Discourses: Book 2 12 : 1
What a man ought to learn before he will know how to conduct an argument has been precisely defined by the philosophers of our school; but as to the proper use of what we have learned we are still utterly inexperienced. At all events, give to anyone of us you please some layman with whom to carry on an argument; he will find no way of dealing with him, but after moving the man a little, in case the latter thwarts him, our man gives up trying to handle him, and thereafter either reviles him, or laughs him to scorn, and remarks, "He is a mere layman; it is impossible to do anything with him." But the real guide, whenever he finds a person going astray, leads him back to the right road, instead of leaving him with a scornful laugh or an insult. So also do you show him the truth and you will see that he follows. But so long as you do not show him the truth, do not laugh him to scorn, but rather recognize your own incapacity.