Institutio Oratoria
Quintilian
Quintilian. Institutio Oratoria, Volume 1-4. Butler, Harold Edgeworth, translator. Cambridge, Mass; London: Harvard University Press, William Heinemann Ltd., 1920-1922.
But teachers must also insist on receiving an attentive and quiet hearing from the class when they themselves declaim. For the master should not speak to suit his pupil's standard, but they should speak to suit his. Further he should, if possible, keep his eyes open to note the points which each boy praises and observe the manner in which he expresses his approval, and should rejoice that his words give pleasure not only for his own sake, but for that of those who show sound judgment in their appreciation.
I do not approve of boys sitting mixed with young men. For even if the teacher be such an one as we should desire to see in charge of the morals and studies of the young, and can keep his youthful pupils under proper control, it is none the less desirable to keep the weaker members separate from the more mature, and to avoid not only the actual charge of corruption but the merest suspicion of it.
I have thought it worth while to put my views on this subject quite briefly. For I do not think it necessary even to warn the teacher that both he and his school must be free from the grosser vices. And should there be any father who does not trouble to choose a teacher for his son who is free from the obvious taint of immorality, he may rest assured that all the other precepts, which I am attempting to lay down for the benefit of our youth, will be absolutely useless to him, if he neglects this.
III. I do not think that I should pass by in silence
I do not think that I need waste much time in pointing out how much better it is to absorb the best possible principles, or how hard it is to get rid of faults which have once become engrained; for it places a double burden on the shoulders of the later teacher and the preliminary task of unteaching is harder than that of teaching.