54 ON GOETHE'S SCIENTIFIC EESEAECHES. 



frangibility than the red rays of light, but are in every 

 other respect exactly similar to them. All these rays, 

 whether luminous or non-luminous, have heating proper- 

 ties, but only a certain number of them, to which for that 

 reason we give the name of light, can penetrate through 

 the transparent part of the eye to the optic nerve, and 

 excite a sensation of light. Perhaps the relation between 

 our senses and the external world may be best enunciated 

 as follows : our sensations are for us only symbols of the 

 objects of the external world, and correspond to them 

 only in some such way as written characters or articulate 

 words to the things they denote. They give us, it is true, 

 information respecting the properties of things without 

 us, but no better information than we give a Wind man 

 about colour by verbal descriptions. 



We see that science has arrived at an estimate of the 

 senses very different from that which, was present to the 

 poet's mind. And Newton's assertion that white was 

 composed of all the colours of the spectrum was the first 

 germ of the scientific view which has subsequently been 

 developed. For at that time there were none of those 

 galvanic observations which paved the way to a know- 

 ledge of the functions of the nerves in the production of 

 sensations. Natural philosophers asserted that white, to 

 the eye the simplest and purest of all our sensations of 

 colour, was compounded of less pure and complex mate- 

 rials. It seems to have flashed upon the poet's mind that 

 all his principles were unsettled by the results of this 

 assertion, and that is why the hypothesis seems to him so 

 unthinkable, so ineffably absurd. "We must look upon 

 his theory of colour as a forlorn hope, as a desperate at- 

 tempt to rescue from the attacks of science the belief in 

 the direct truth of our sensations. And this will account, 

 for the enthusiasm with which he strives to elaborate and 

 to defend his theory, for the passionate irritability with 



