Institutio Oratoria
Quintilian
Quintilian. Institutio Oratoria, Volume 1-4. Butler, Harold Edgeworth, translator. Cambridge, Mass; London: Harvard University Press, William Heinemann Ltd., 1920-1922.
The reason which leads me to deal with this subject in this portion of my work is not that I regard character as a matter of indifference where other teachers are concerned, (I have already shown how important I think it in the preceding book), but that the age to which the pupil has now attained makes the mention of this point especially necessary.
For as a rule boys are on the verge of manhood when transferred to the teacher of rhetoric and continue with him even when they are young men: consequently we must spare no effort to secure
Nor is it sufficient that he should merely set an example of the highest personal self-control; he must also be able to govern the behaviour of his pupils by the strictness of his discipline.