This course of conduct seems difficult because we do not reflect upon it; but taking it altogether, it ought not to be so. I am justified in supposing that you know enough to understand the business you have undertaken; that you know the natural progress of the human mind; that you understand studying mankind in general and in individual cases; that among all the objects interesting to his age that you mean to show your pupil, you know beforehand which of them will influence his will. Now if you have the appliances, and know just how to use them, are you not master of the operation? You object that children have caprices, but in this you are mistaken. These caprices result from faulty discipline, and are not natural. The children have been accustomed either to obey or to command, and I have said a hundred times that neither of these two things is necessary. Your pupil will therefore have only such caprices as you give him, and it is just you should be punished for your own faults. But do you ask how these are to be remedied? It can still be done by means of better management and much patience. Physical Training. Man's first natural movements are for the purpose of comparing himself with whatever surrounds him and finding in each thing those sensible qualities likely to affect himself. His first study is, therefore, a kind of experimental physics relating to his own preservation. From this, before he has fully understood his place here on earth, he is turned aside to speculative studies. While yet his delicate and pliable organs can adapt themselves to the objects upon which they are to act, while his senses, still pure, are free from illusion, it is time to exercise both in their peculiar functions, and to learn the perceptible relations between ourselves and outward things. Since whatever enters the human understanding enters by the senses, man's primitive reason is a reason of the senses, serving as foundation for the reason of the intellect. Our first teachers in philosophy are our own feet, hands, and eyes. To substitute books for these is teaching us not to reason, but to use the reason of another; to believe a great deal, and to know nothing at all.