He worked over it eighteen months. There is no part of this harmonious figure that has not been passionately thought out. He had to render, beneath the supple covering of the skin, those firm, fine muscles which possess the elasticity of youth and its sobriety. In giving the sense of the presence of these things, one creates the illusion of their activity. This is the secret of great sculpture and of all the arts, to evoke that which we do not see by the quality of that which we do see. "Carefully examine the Venus de Medici," Rude used to advise his pupils, "and under the polish of the skin you will see the whole muscular system appear." Rodin did not spare either his own strength or that of his model. An implacable goddess led him on, his conscience. He did not content himself with rendering only the masses that his direct vision gave him. In this way he would have possessed only two dimensions, the length and width of the human body. He needed the exact relief of masses, which is the basis of _ronde-bosse_, of "cubic sculpture." He studied his profiles not only from below, but from above. He mounted a painting ladder and looked down over his model; he measured the surface of the skull, which, seen from above, has an ovoid form; he took and compared with his clay model the dimensions of the shoulders, the chest, the hips, the feet as they appeared with the floor as a background. He observed the points where the arm muscles were inserted, and those of the thighs and the legs. How, after such a rigorously minute process of noting his masses, could his work be flat? That became impossible. But the geometric labor, the taking of measurements, was not all. The next question was to reassemble the different profiles by careful transcription. There is an entire school of conscientious sculptors who believe that they can obtain reality by the simple method of making identical points correspond. They multiply the measurements taken from the model with the aid of a plumb-line and a compass; it is only a mechanical process which does not even give good practical effects. To unify the manifold surface of the human body, to endow the whole with the suppleness of life, with its harmonious continuity and poise, the personal judgment of the artist must unceasingly intervene. His own special taste is supremely what adjusts the elements which are waiting to be unified by him in order to take on animation and to live one beside another. It is during this last effort that the expression, summoned up by the truth of the ensemble, comes almost of itself to the fingers of the sculptor. If the preceding principles have not been scrupulously observed, it seems to refuse to come; it is the reward only of conscience joined with intelligence; it is the fruit of this indissoluble union that works in the spirit of the true artist. The true expression is that to which we give the indefinable name of poetry. [Illustration: MAN AWAKENING TO NATURE.]