WHAT IS PHYSICAL LIFE 



quite justified in blaming his carelessness 

 in the strongest terms and giving him back 

 his instrument. Of course I shall not do 

 this with my eyes, and shall be only too 

 glad to keep them as long as I can 

 defects and all. Still, the fact that 

 however bad they may be, I can get no 

 others, does not at all diminish their 

 defects." 



Helmholtz is here speaking of the eye 

 only as an optical instrument used for the 

 ordinary purposes of life, and for these he 

 finds it abounding in deficiencies. He does 

 not allude at all to its utter inadequacy as 

 a help for us to go beyond our customary 

 world. But ordinarily no one's eye recog- 

 nizes anything clearly within eight, and 

 with many, ten, inches of his eyeball. 

 What is there to see within that distance? 

 Not until a microscope was made could 

 any one tell. It is a mistake, however, to 

 suppose that this artificial supplement to 

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