But how, you may object, can you tell me that there are many thousands of images there, where I can see none at all? Besides, as there is but one colour in the sun, why are there different colours in the 10 reflections of him? These objections which you have put forward, as well as others that no less call for refutation, I will endeavour to refute. And let me say, first of all, that nothing is more deceptive than our eyesight, not merely in objects whose careful examination is prevented by distance in position,[26] but even in objects seen close at hand. An oar, though quite whole, presents the appearance of being broken when seen in clear shallow water. Apples seen through glass appear much larger than they really are. In long colonnades, pillars 11 set at intervals present an apparently unbroken continuity of line. Or go back to the case of the sun himself; his orb, which reason proves to be larger than the whole earth, is so contracted by human sight that some of the philosophers have maintained that it is only a foot in diameter. He is, we know, the swiftest of all luminaries, yet none of us can see him move; nor should we believe that he does advance, were it not evident from time to time that he has advanced. The world itself glides on with headlong speed; within an instant of time it unfolds its risings and its settings, yet none of us is aware of its movement. What cause, then, is there for wonder if our eyesight cannot separate 12 the drops of the rain showers, and loses the distinction of the images on account of the vast distance at which they are beheld? At any rate no one can doubt this, that the rainbow is a reflection of the sun, formed in a hollow cloud full of moisture. This is made plain from the simple fact that the image is never seen except opposite the sun, high up or low down, in inverse relation, just as he sinks or elevates his course. When he descends, it is higher; when he is high in the heavens, it is more sunken. A cloud of the required kind is often at the side 13 of the sun without producing a rainbow, because it does not catch his image straight in front. [26] The received text gives “diversity of colours.”