312 RECEXT PROGRESS OF THE THEORY OF VISION. 



supposed) may be accepted or avoided as we please, are 

 not worth much. 



The reader will see that these investigations have led 

 us to a field of mental operations which has been seldom 

 entered by scientific explorers. The reason is that it is 

 difficult to express these operations in words. They have 

 been hitherto most discussed in writings on aesthetics, 

 where they play an important part as Intuition, Uncon- 

 scious Eatiocination, Sensible Intelligibility, and such 

 obscure designations. There lies under all these phrases 

 the false assumption that the mental operations we are 

 discussing take place in an undefined, obscure, half- 

 conscious fashion ; that they are, so to speak, mechanical 

 operations, and thus subordinate to conscious thought, 

 which can be expressed in language. I do not l)elieve 

 that any difference in kind between the two functions 

 can be proved. The enormous superiority of knowledge 

 which has become ripe for expression in language, is 

 sufficiently explained by the fact that, in the first place, 

 speech makes it possible to collect together the ex- 

 perience of millions of individuals and thousands of 

 generations, to preserve them safely, and by continual 

 verification to make them gradually more and more 

 certain and universal ; while, in the second place, all 

 deliberately combined actions of mankind, and so the 

 greatest part of human power, depend on language. In 

 neither of these respects can mere familiarity with phe- 

 nomena {das Kennen) compete with the knowledge of 

 them which can be communicated by speech (das Wis- 

 sen) ; and yet it does not follow of necessity that the 

 one kind of knowledge should be of a different nature 

 from the other, or less clear in its operation. 



The supporters of Intuitive Theories of Sensation often 

 appeal to the capabilities of new-born animals, many of 



