It may be objected that a color cannot be less large, and that it can only be less vivid. However, there is a common characteristic in something smaller and less vivid; namely, that it is less than what it is its being to be. As to color, diminution implies weakness; as to size, smallness. Magnitude connected with color diminishes proportionally with it. This is evident in the perception of a varied object, as, for instance, in the perception of mountains covered with houses, forests, and many other objects; here the distinctness of detail affords a standard by which to judge of the whole. But when the view of the details does not impress itself on the eye, the latter no longer grasps the extent of the whole through measurement of the extent offered to its contemplation by the details. Even in the case where the objects are near and varied, if we include them all in one glance without distinguishing all their parts, the more parts our glance loses, the smaller do the objects seem. On the contrary, if we distinguish all their details, the more exactly do we measure them, and learn their real size. Magnitudes of uniform color deceive the eye because the latter can no longer measure their extent by its parts; and because, even if the eye attempt to do so, it loses itself, not knowing where to stop, for lack of difference between the parts. DISAPPEARANCE OF THE FORM IMPLIES THAT OF THE SIZE. The distant object seems to us close because our inability to distinguish the parts of the intervening space does not permit us to determine exactly its magnitude. When sight can no longer traverse the length of an interval by determining its quality, in respect to its form, neither can it any longer determine its quantity in respect to magnitude. REFUTATION OF ARISTOTLE'S "VISUAL ANGLE" THEORY.