CORRESPONDENCE 



To the Editor of " Science Progress " 



" THE MIRROR OF PERCEPTION " 



Sir, — Will you kindly afford me space to reply to the criticisms 

 contained in the review of my book, The Mirror of Perception, 

 which appears in the current issue of Science Progress ? 



I desire, in the first place, to express my appreciation of 

 the reviewer's generous recognition of merit in the book, all 

 the more so that he does not agree with my conclusions. 



The reviewer says : " The representation of matter in 

 terms of consciousness does not, properly understood, involve 

 any falling off in the ' reality ' of material existence. It 

 would be as reasonable to say that because colour can be 

 represented in terms of ethereal undulations, therefore it 

 ceases to be real." 



This comparison would be valid against me if, and only 

 if, I based my reasons for believing that matter is not real on 

 the distortion which the secondary qualities of bodies (e.g. 

 colour) have undergone in the process leading to their per- 

 ception ; but all these reasons are based on the distortion 

 which the spatial qualities of matter have undergone, the 

 first thing which I set out to establish being the fact of this 

 distortion. 



If the positions of the various points of a body are changed 

 according to any fixed law, we get, as the result, an unreal 

 image of the body, a thing which does not exist, but only 

 appears to exist. Thus, as I say on p. 13, " the question of 

 the reality of material bodies depends entirely on the question 

 whether space is real or not." A few lines further on I admit 

 that the distortion of the secondary qualities of bodies has 

 no effect on their reality, if space is real ; for I say, arguing 

 on the supposition that space is real, " even if our knowledge 

 of material bodies is not true knowledge of them, there is 



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