When the academic school wishes to make use of a background to a figure it confines itself to a hollow or a relief. Rodin desired that a statue should stand free and should bear looking at from any point, but he desired nevertheless that it should remain in relation with light and with the surrounding atmosphere. He was struck by the hard, cut-out aspect of ordinary statues, and asked himself how an atmosphere might be given to them. Painting has two means to this end: of which the first is _values. Values_ are independent of colour. Values, an element common to both arts, are in painting and sculpture _the relations as to opacity or transparence of an object and the background against which it is seen._ They may be dark on a light ground, light on a dark ground, or light upon a ground that is likewise light; but they are always the very life of the outline, and the important point is to fix that outline first of all. When we see a person placed between the sun and ourselves, against the light, we do not at first perceive the details within the outline, but we do see the general mass of the body, and that mass is filled with more or less intense colour, in which we presently distinguish details. Our perception at the moment is as much sculptural as pictorial. Rodin, struck by the importance of this idea, devoted himself to obtaining, _at once and together,_ the _volume;_ that is to say, the equivalent in sculpture of the _value,_ and the design of _successive views of one movement._ But the second means in painting is the employment of intermediate tones encircling the figure and combining with the background. How could an equivalent be found for that? Logic led Rodin on to a step which alarmed him: he made experiments after examining the antiques very closely. He took fragments of his statues and began to raise them in certain places by layers of clay, intensifying the modelling and enlarging the lines. He observed that the light now played better upon these enlarged lines; the refraction of light upon these amplified surfaces was softer, the hardness of the cut-out outline vanished, and a radiant zone shaped itself around his figures and united them gradually with the atmosphere. In this way, therefore, by means of this systematic accentuation of the outlines, an intermediate tone, _a radiancy of the forms,_ was produced.