“He who teaches others, teaches himself,” is very true, not only because constant repetition impresses a fact indelibly on the mind, but because the process of teaching in itself gives a deeper insight into the subject taught. Thus it was that the gifted Joachim Fortius29 used to say that, if he had heard or read anything once, it slipped out of his memory within a month; but that if he taught it to others it became as much a part of himself as his fingers, and that he did not believe that anything short of death could deprive him of it. His advice, therefore, was that, if a student wished to make progress, he should arrange to give lessons daily in the subjects which he was studying, even if he had to hire his pupils. “It is worth your while,” he says, “to sacrifice your bodily comfort to a certain extent for the sake of having some one who will listen while you teach, or, in other words, while you make intellectual progress.”
45. This would certainly be of use to many and could easily be put into practice if the teacher of each class would introduce this excellent system to his pupils. It might be done in the following way: in each lesson, after the teacher has briefly gone through the work that has been prepared, and has explained the meanings of the words, one of the pupils should be allowed to rise from his place and repeat what has just been said in the same order (just as if he were the teacher of the rest), to give his explanations in the same words, and to employ the same examples, and if he make a mistake he should be corrected. Then another can be called up and made go through the same performance while the rest listen. After him a third, a fourth, and as many as are necessary, until it is evident that all have understood the lesson and are in a position to explain it. In carrying this out great care should be taken to call up the clever boys first, in order that, after their example, the stupid ones may find it easier to follow.
46. Exercises of this kind will have a fivefold use.
(i) The teacher is certain to have attentive pupils. For since the scholars may, at any time, be called up and asked to repeat what the teacher has said, each of them
