Younger children also have their uses, especially in the years from three to six; these uses are chiefly in connection with moral education. So long as a child is with adults, it has no occasion for the exercise of a number of important virtues, namely, those required by the strong in dealing with the weak. A child has to be taught not to take things by force from a younger brother or sister, not to show excessive anger when the junior inadvertently knocks over his tower of bricks, not to hoard toys he is not using which the other desires. He has to be taught that the junior can be easily hurt by rough handling, and to feel compunction when he has wantonly caused tears. In protecting a younger child, one can speak to the senior with a sharpness and suddenness which would not otherwise be justified, but which have their uses through the strong impression produced by their unexpectedness. All these are useful lessons, which it is hardly possible to give naturally in any other way. It is a folly and a waste of time to give abstract moral instruction to a child; everything must be concrete, and actually demanded by the existing situation. Much that, from an adult point of view, is moral education, feels to the child just like instruction in handling a saw. The child feels that he is being shown how the thing is done. That is one reason why example is so important. A child who has watched a carpenter at work tries to copy his movements; a child who has seen his parents behaving always with kindness and consideration tries to copy them in this respect. In each case, prestige is attached to what he wants to imitate. If you gave your child a solemn lesson in the use of a saw, but yourself always tried to use it as a chopper, you would never make a carpenter of him. And if you urge him to be kind to his little sister, but are not kind to her yourself, all your instruction will be wasted. For that reason, when you have to do something that makes a little child cry, such as cleaning its nose, you should be careful to explain to the older child why it is necessary to do it. Otherwise he is quite likely to rise up in defence of the younger child, and fight you to make you stop being cruel. If you allow him to remain under the impression that you are cruel, you will have lost the power to curb his own impulses towards tyranny.