1. What is the cause that when distant visible objects seem smaller, and that, though separated by a great space, they seem to be close to each other, while if close, we see them in their true size, and their true distance? The cause of objects seeming smaller at a distance might be that light needs to be focussed near the eye, and to be accommodated to the size of the pupils[50]; that the greater the distance of the matter of the visible object, the more does its form seem to separate from it during its transit to the eyes; and that, as there is a form of quantity as well as of quality, it is the reason (or, form) of the latter which alone reaches the eye. On the other hand, (Epicurus) thinks that we feel magnitude only by the passage and the successive introduction of its parts, one by one; and that, consequently, magnitude must be brought within our reach, and near us, for us to determine its quantity. QUALITY IS MORE ESSENTIAL THAN QUANTITY. (Do objects at a distance seem smaller) because we perceive magnitude only by accident, and because color is perceived first? In this case, when an object is near, we perceive its colored magnitude; when at a distance, we perceive first its color, not well enough distinguishing its parts to gather exact knowledge of its quantity, because its colors are less lively. Why should we be surprised at magnitudes being similar to sounds, which grow weaker as their form decreases in distinctness? As to sounds, indeed, it is the form that is sought by the sense of hearing, and here intensity is noticed only as an accident. But if hearing perceive magnitude only by accident, to what faculty shall we attribute the primitive perception of intensity in sound, just as primitive perception of magnitude in the visible object is referable to the sense of touch? Hearing perceives apparent magnitude by determining not the quantity but the intensity of sounds; this very intensity of sounds, however, is perceived only by accident (because it is its proper object). Likewise, taste does not by accident feel the intensity of a sweet savor. Speaking strictly, the magnitude of a sound is its extent. Now the intensity of a sound indicates its extent only by accident, and therefore in an inexact manner. Indeed a thing's intensity is identical with the thing itself. The multitude of a thing's parts is known only by the extent of space occupied by the object. DIFFERENCES OF COLOR AID IN THE PERCEPTION OF MAGNITUDE.