2.2.1 Thus, when a child has arrived at such powers (=acquired such abilities) in studying that he can keep up with what I've called by (the above) judgement the first part of (the discipline of) the rhetors, he will have to be entrusted to the teachers of this art. Among the first (=especially) their characters have to be inspected:
2.2.2 I have begun to discuss this topic (>quod) chiefly in this part, not for the reason that I don't think that the same thing must be examined as carefully as possible in regard to other teachers as well, just as I've attested in the previous book, but because the age of the students makes the mention of this thing more necessary.
2.2.3 For, the children, who are almost grown up, are transferred to these teachers (of rhetorics) and, even after having been made (=grown up to be) young men, they abide with them; Thus greater care must be applied then so that both the sacredness of the teacher would guard (the children of) younger ages (than others) from injustice and the severity (of the teacher) would avert children who are fiercer (than others) (those in) fiercer period from licentiousness. * cf. Wtb. comment.
2.2.4 It is not quite enough to be responsible for the greatest self-restraint (by himself) unless he also tightens the behaviours of those coming to him (=his school) by the severity of discipline. // Thus, first of all, he (=a rhetor) must apply the mind of their parents towards his students, and think that he succeeds the postion (=role) of those from whom the sons are entrusted to him.
2.2.5 He mustn't have nor tolerate any vice. His severity mustn't be offensive, nor must his politeness be dissolved, so that neither hatred thence nor contempt hence would rise. He must have many talks about honesty and goodness: for, the more often he has warned (the students), the more rarely he will castigate (them); He (must be) least angry and, however, he (must) not (be) a concealer of those which will have to be amended; (he must be) simple in teaching, patient of the labour, and constant rather than immoderate.
2.2.6 He must respond willingly to those asking (him) and he must spontaneously inquire those not asking. When praising the oratories of the students, (he must be) neither malignant nor lavish, because one thing (=the former) produces tedium of the labour (=studying) and the other (=the latter) carelessness.
2.2.7 When amending what will have to be corrected, (he must be) not harsh and the least abusive, for it puts to flight many (students) indeed from the plan of studying, because someone (of the teachers) scold (them) as if he (hated) him.