See a cat entering for the first time in a room; he visits, he watches, he smells, he doesn't remain one moment in rest, he doesn't trust anything that after having examined everything, all known. Makes an early child thus to walk, and, incoming so to speak in the space of the world. The whole difference is that to the view, common to the child and to the cat, the first joint, to observe, the hands that the nature gave to him, and the other the subtle smell of which it endowed it. This disposition, well or badly cultivated, is what returns the skillful or heavy, heavy or fresh, lightheaded or prudent children."

"Emile or Of the education" [Jean-Jacques Rousseau 1762]