THE METAPHYSICS OF SENSATION 263 



become so fused together that they are often con- 

 founded under the same name. 



If freedom to move in all directions is the very 

 essence of that conception of space of three dimen- 

 sions which we obtain by the sense of touch ; and 

 if that freedom to move is really another name 

 for the feeling of unopposed effort, accompanied 

 by that of change of place, it is surely impossible 

 to conceive of such space as having existence apart 

 from that which is conscious of effort. 



But it may be said that we derive our concep- 

 tion of space of three dimensions not only from 

 touch, but from vision ; that if we do not feel 

 things actually outside us, at any rate we see 

 them. And it was exactly this difficulty which 

 presented itself to Berkeley at the outset of his 

 speculations. He met it, with characteristic bold- 

 ness, by denying that we do see things outside us ; 

 and, with no less characteristic ingenuity, by de- 

 vising that " New Theory of Vision " which has 

 met with wider acceptance than any of his views, 

 though it has been the subject of continual con- 

 troversies. 1 



In the "Principles of Human Knowledge," 

 Berkeley himself tells us how he was led to those 



1 I have not specifically alluded to the writings of Bailey, 

 Mill, Abbott, and others, on this vexed question, not because I 

 have failed to study them carefully, but because this is not a 

 convenient occasion for controversial discussion. Those who are 

 acquainted with the subject, however, will observe that the 

 view I have taken agrees substantially with that of Mr. Bailey. 



