The artist may suggest brilliant sunlight by means of deep shadow. The old painters gained color at the expense of light and therefore lowered the scale of color in their representations of nature. It is interesting to see how increasing knowledge, as centuries passed, directed painters as it did others onward toward the truth. Turner was one of the first to abandon the older methods in an attempt to raise the scale of his paintings toward a brilliance more resembling nature. By doing this he was able to put color in shadows as well as in lights. Gradually paintings became more brilliant. Monet, Claude, and others worked toward this goal until the brightnesses of paintings reached the limits of pigments. The impressionists, in their desire to paint nature's light, introduced something which was nothing more nor less than science. All this time the true creative artist was introducing science--in fact, illusions--to produce the perfect illusion which was his goal. A survey of any representative paintings' gallery shows the result of the application of more and more knowledge, as the art of painting progressed through the centuries. Surely we cannot go back to the brown shadows and sombre landscapes of the past. In the earliest art, in the efforts of children, in the wall-paintings of the Egyptians, and in Japanese representation of nature, the process is selective and not imitative. Certain things are chosen and everything else is discarded. In such art selection is carried to the extreme. Much of this simplicity was due to a lack of knowledge. Light and shade, or shading, was not introduced until science discovered and organized its facts. Quite in the same manner linear and aerial perspective made their appearances until in our present art the process of selection is complex. In our paintings of today objects are modeled by light and shade; they are related by perspective; backgrounds and surroundings are carefully considered; the proper emphasis of light, shade and color are given to certain details. The present complexity provides unprecedented opportunities for the application of knowledge pertaining to illusions but it should be understood that this application tends only toward realism of external things. Idealism in art and realism of character and expression are accomplished by the same tools--pigments and brushes--as realism of objective details is attained and there is nothing mysterious in the masterpieces of this kind. Mystery in art as in other activities is merely lack of understanding due to inadequate knowledge. Mysteries of today become facts tomorrow. Science moves with certainty into the unknown, reaping and binding the facts and dropping them behind where they may be utilized by those who will.