Book 7
10.8
But it is clearly useless to take one or two cases, or even a hundred or a thousand, since their number is infinite. It is the duty of the teacher to demonstrate daily in one kind of case after another what is the natural order and connexion of the parts, so that little by little his pupils may gain the experience which will enable them to deal with other cases of the same character. For it is quite impossible to teach everything that can be accomplished by art.
10.9
For example, what painter has ever been taught to reproduce everything in nature? But once he has acquired the general principles of imitation, he will be able to copy whatever is given him. What vase-maker is there who has not succeeded in producing a vase of a type which he had never previously seen?
10.10
There are, however, some things which depend not on the teacher, but on the learner. For example, a physician will teach what treatment should be adopted for different diseases, what the dangers are against which he must be on his guard, and what the symptoms by which they may be recognised. But he will not be able to communicate to his pupil the gift of feeling the pulse, or appreciating the variations of colour, breathing and temperature: this will depend on the talent of the individual. Therefore, in most instances, we must rely on ourselves, and must study cases with the utmost care, never forgetting that men discovered our art before ever they proceeded to teach it.
