274 THE METAPHYSICS OF SENSATION 



to me that it is the special peculiarity of visual 

 sensations, that they invariably give rise to the 

 idea of remoteness, and that Berkeley's dictum 

 ought to be reversed. For I think that any one 

 who interrogates his consciousness carefully will 

 find that " every proper visual idea " appears to be 

 without the mind and at a distance off. 



Not only does every visibile appear to be re- 

 mote, but it has a position in external space, just 

 as a tangibile appears to be superficial and to have 

 a determinate position on the surface of the body. 

 Every visibile, in fact, appears (approximately) to 

 be situated upon a line drawn from it to the point 

 of the retina on which its image falls. It is re- 

 ferred outwards, in the general direction of the 

 pencil of light by which it is rendered visible, just 

 as, in the experiment with the stick, the tangibile 

 is referred outwards to the end of the stick. 



It is for this reason that an object, viewed with 

 both eyes, is seen single and not" double. Two 

 distinct images are formed, but each image is 

 referred to that point at which the two optic axes 

 intersect; consequently, the two images cover 

 one another, and appear as completely one as any 

 other two equally similar super-imposed images 

 would be.* And it is for the same reason, that, if 

 the side of the ball of the eye is pressed upon at 

 any point, a spot of light appears apparently out- 



* In the case of a near, solid, external object, such as a 

 cube, this is not the whole story. 



