We have not equal control of all our senses. One of them, the sense of touch, is in continual action so long as we are awake. Diffused over the entire surface of the body, it serves as a perpetual sentinel to warn us of what is likely to harm us. By the constant use of this sense, voluntary or otherwise, we gain our earliest experience. It therefore stands less in need of special cultivation. We observe however, that the blind have a more delicate and accurate touch than we, because, not having sight to guide them, they depend upon touch for the judgments we form with the aid of sight. Why then do we not train ourselves to walk, like them, in the dark, to recognize by the touch all bodies we can reach, to judge of objects around us, in short, to do by night and in the dark all they do in daytime without eyesight? So long as the sun shines, we have the advantage of them; but they can guide us in darkness. We are blind during half our life-time, with this difference, that the really blind can always guide themselves, whereas we dare not take a step in the dead of night. You may remind me that we have artificial light. What! must we always use machines? Who can insure their being always at hand when we need them? For my part, I prefer that Émile, instead of keeping his eyes in a chandler's shop, should have them at the ends of his fingers. As much as possible, let him be accustomed to play about at night. This advice is more important than it would seem. For men, and sometimes for animals, night has naturally its terrors. Rarely do wisdom, or wit, or courage, free us from paying tribute to these terrors. I have seen reasoners, free-thinkers, philosophers, soldiers, who were utterly fearless in broad daylight, tremble like women at the rustle of leaves by night. Such terrors are supposed to be the result of nursery tales. The real cause is the same thing which makes the deaf distrustful, and the lower classes superstitious; and that is, ignorance of objects and events around us. The cause of the evil, once found, suggests the remedy. In everything, habit benumbs the imagination; new objects alone quicken it again. Every-day objects keep active not the imagination, but the memory; whence the saying "Ab assuetis non fit passio."[22] For only the imagination can set on fire our passions. If, therefore, you wish to cure any one of the fear of darkness, do not reason with him. Take him into the dark often, and you may be sure that will do him more good than philosophical arguments. When at work on the roofs of houses, slaters do not feel their heads swim; and those accustomed to darkness do not fear it at all.