What a sudden change you will say. Just now we were concerned with what touches ourselves, with our immediate environment, and all at once we are exploring the round world and leaping to the bounds of the universe. This change is the result of our growing strength and of the natural bent of the mind. While we were weak and feeble, self-preservation concentrated our attention on ourselves; now that we are strong and powerful, the desire for a wider sphere carries us beyond ourselves as far as our eyes can reach. But as the intellectual world is still unknown to us, our thoughts are bounded by the visible horizon, and our understanding only develops within the limits of our vision. Let us transform our sensations into ideas, but do not let us jump all at once from the objects of sense to objects of thought. The latter are attained by means of the former. Let the senses be the only guide for the first workings of reason. No book but the world, no teaching but that of fact. The child who reads ceases to think, he only reads. He is acquiring words not knowledge. Teach your scholar to observe the phenomena of nature; you will soon rouse his curiosity, but if you would have it grow, do not be in too great a hurry to satisfy this curiosity. Put the problems before him and let him solve them himself. Let him know nothing because you have told him, but because he has learnt it for himself. Let him not be taught science, let him discover it. If ever you substitute authority for reason he will cease to reason; he will be a mere plaything of other people's thoughts. You wish to teach this child geography and you provide him with globes, spheres, and maps. What elaborate preparations! What is the use of all these symbols; why not begin by showing him the real thing so that he may at least know what you are talking about?