But the wide expansion of this field and of the whole manifoldness of emotional possibilities in the moving pictures is not sufficiently characterized as long as we think only of the optical representation in the actual outer world. The camera men of the moving pictures have photographed the happenings of the world and all its wonders, have gone to the bottom of the sea and up to the clouds; they have surprised the beasts in the jungles and in the Arctic ice; they have dwelt with the lowest races and have captured the greatest men of our time: and they are always haunted by the fear that the supply of new sensations may be exhausted. Curiously enough, they have so far ignored the fact that an inexhaustible wealth of new impressions is at their disposal, which has hardly been touched as yet. There is a material and a formal side to the pictures which we see in their rapid succession. The material side is controlled by the content of what is shown to us. But the formal side depends upon the outer conditions under which this content is exhibited. Even with ordinary photographs we are accustomed to discriminate between those in which every detail is very sharp and others, often much more artistic, in which everything looks somewhat misty and blurring and in which sharp outlines are avoided. We have this formal aspect, of course, still more prominently if we see the same landscape or the same person painted by a dozen different artists. Each one has his own style. Or, to point to another elementary factor, the same series of moving pictures may be given to us with a very slow or with a rapid turning of the crank. It is the same street scene, and yet in the one case everyone on the street seems leisurely to saunter along, while in the other case there is a general rush and hurry. Nothing is changed but the temporal form; and in going over from the sharp image to the blurring one, nothing is changed but a certain spatial form: the content remains the same.