On the basis of the favorable stimulations of all these activities taken together, must we judge as pleasing the so- called quality of line. But it is clear that we cannot really separate the question of quality of line from that of form, figure, and arrangement in space. The motor innervations enter with the first, and the moment we have form at all, we have space-composition also. But space-composition means unity, and unity is the objective quality which must be translated, in our investigations, into aesthetic repose. It is thus with the study of composition that we pass from the study of the elements as favorably stimulating, to the study of the beauty of visual form. V We may begin by asking what, as a matter of fact, has been the arrangement of spaces to give aesthetic pleasure. The primitive art of all nations shows that it has taken the direction of symmetry about a vertical line. It might be said that this is the result of non-aesthetic influences, such as convenience of construction, technique, etc. <1>It is clear that much of the symmetry appearing in primitive art is due (1) to the conditions of construction, as in the form of dwellings, binding patterns, weaving and textile patterns generally; (2) to convenience in use, as in the shapes of spears, arrows, knives, two-handled baskets or jars; (3) to the imitation of animal forms, as in the shapes of pottery, etc. On the other hand, (1) a very great deal of symmetrical ornament maintains itself AGAINST the suggestions of the shape to which it is applied, as the ornaments of baskets, pottery, and all rounded objects; and (2) all distortion, disintegration, degradation of pattern- motives, often so marked as all but to destroy their meaning, is in the direction of geometrical symmetry. The early art of all civilized nations shows the same characteristic. Now it might be said that, as there exists an instinctive tendency to imitate visual forms by motor impulses, the impulses suggested by the symmetrical form are in harmony with the system of energies of our bilateral organism, which is a system of double motor innervations, and thus fulfill our demand for a set of reactions corresponding to the organism as a whole. But we should then expect that all space arrangements which deviate from complete symmetry, and thus suggest motor impulses which do not correspond to the natural bilateral type, would fail to give aesthetic pleasure. Such, however, is not the case. Non-symmetrical arrangements of space are often extremely pleasing. <1> The following is adapted from the author's _Studies in Symmetry, Harvard Psych. Studies_, vol i, 1902. This contradiction disappears if we are able to show that the apparently non-symmetrical arrangement contains a hidden symmetry, and that all the elements of that arrangement contribute to bring about just that bilateral type of motor impulses which is characteristic of geometrical symmetry.