Further; it is demonstrated that there is formed in my eye an angle a degree larger when a thing is near, when I see a man four feet from me than when I see the same man at a distance of eight feet. However, I always see this man of the same size. How does my mind thus contradict the mechanism of my organs? The object is really a degree smaller to my eyes, and yet I see it the same. It is in vain that we attempt to explain this mystery by the route which the rays follow or by the form taken by the crystalline humor of the eye. Whatever may be supposed to the contrary, the angle at which I see a man at four feet from me is always nearly double the angle at which I see him at eight feet. Neither geometry nor physics will explain this difficulty. These geometrical lines and angles are not really more the cause of our seeing objects in their proper places than that we see them of a certain size and at a certain distance. The mind does not consider that if this part were to be painted at the bottom of the eye it could collect nothing from lines that it saw not. The eye looks down only to see that which is near the ground, and is uplifted to see that which is above the earth. All this might be explained and placed beyond dispute by any person born blind, to whom the sense of sight was afterwards attained. For if this blind man, the moment that he opens his eyes, can correctly judge of distances, dimensions, and situations, it would be true that the optical angles suddenly formed in his retina were the immediate cause of his decisions. Doctor Berkeley asserts, after Locke--going even further than Locke--that neither situation, magnitude, distance, nor figure would be discerned by a blind man thus suddenly gifted with sight.