Now as we have no possible means of distinguishing things other than by their attributes, the classification of these entails a fundamental order of arrangement comprehending everything. Henceforth the world is no longer a chaos for the child; his mind bears some resemblance to the orderly shelves of a library or a rich museum; each object is in its place, in its proper category. And each acquisition he makes will be no longer merely "stored," but duly "allocated." This primitive order will never be disturbed, but only enriched by fresh material. Thus the child, having acquired the power of distinguishing one thing from another, has laid the foundations of the intelligence. It is unnecessary to repeat what an internal impulse the acquired order contributes towards the seeking after objects in the environment; henceforth the child "recognizes" the objects which surround him. When he discovers with so much emotion that the sky is blue, that his hand is smooth, that the window is rectangular, he does not in reality discover sky, nor hand, nor window, but he discovers their position in the order of his mind by arrangement of his ideas. And this determines a stable equilibrium in the internal personality, which produces calm, strength, and the possibility of fresh conquests, just as the muscles which have coordinated their functions enable the body to maintain its equilibrium, and to acquire that stability and security which facilitate all movements. This order conduces to an economy of time and strength; like a well-arranged museum, it saves the time and strength of inquirers. The child can therefore perform a greater quantity of work without fatigue, and can react to stimuli in a briefer space of time. * * * * * To be able to distinguish, classify, and catalogue external things on the basis of a secure order already established in the mind--this is at once intelligence and culture. This is, indeed, the popular conception; when an educated person can recognize an author by his style, or the characteristics of the literary compositions of a period, he is pronounced "versed (_intelligente_) in literature." In the same way we say of one who can recognize a painter by the manner in which he lays his colors on the canvas, or fix the period of a sculptor from the fragment of a bas-relief, that he is "versed (_intelligente_) in art." The scientist is of the same type. He is able to observe things, and to give due value even to their minutest details; hence the differences between the characteristics of things are clearly perceived and classified. The scientist distinguishes objects in accordance with the orderly content of his mind. A seedling, a microbe, an animal or the remains of an animal, are not enigmas to him, though in themselves they may be strange to him. We may say the same of the chemist, the physicist, the geologist, the archaeologist.