There is a difference between boys and men, but it is a difference of self-knowledge chiefly. A boy wants to do everything because he does not know he cannot; a man wants to do something because he knows he cannot do everything; a boy always fails, and a man sometimes succeeds because the man knows and the boy does not know. A man is better than a boy because he knows better; he has learned by experience that what is a harm to others is a greater harm to himself, and he would rather not do it. But a boy hardly knows what harm is, and he does it mostly without realizing that it hurts. He cannot invent anything, he can only imitate; and it is easier to imitate evil than good. You can imitate war, but how are you going to imitate peace? So a boy passes his leisure in contriving mischief. If you get another fellow to walk into a wasp's camp, you can see him jump and hear him howl, but if you do not, then nothing at all happens. If you set a dog to chase a cat up a tree, then something has been done; but if you do not set the dog on the cat, then the cat just lies in the sun and sleeps, and you lose your time. If a boy could find out some way of doing good, so that he could be active in it, very likely he would want to do good now and then; but as he cannot, he very seldom wants to do good.