Philosophers, psychologists, sociologists and others have centered their interest on the child of 1 ½ to 2 years of age. This is an epoch of development in which special care must be taken not to destroy the tendencies of life. If nature has given us such clear indications that this is the period of maximum effort we must support this effort. This is a general statement, but those who observe become more exact in the details they give. They state that at this epoch the child begins to show an instinct of imitation. This, in itself, is not a new discovery, because at all times people have said that children imitate, but hitherto this was a superficial statement. Now it is realized that the human child must understand before it imitates; this is logical, but it had not occurred to anyone before. The old idea was that we only had to act and the children would follow, there was hardly any further responsibility for the adult. Of course it was also said that we had to set a good example. This sets forth the importance of all adults, especially teachers.