Now the modes of all help and communication from one to another are three. One is, by attending to another, as the master of gymnastics, in training the boy. The second is, by assimilation, as in the case of one who exhorts another to benevolence by practising it before. The one co-operates with the learner, and the other benefits him who receives. The third mode is that by command, when the gymnastic master, no longer training the learner, nor showing in his own person the exercise for the boy to imitate, prescribes the exercise by name to him, as already proficient in it.