306 THE RIDDLE OF THE UNIVERSE. 



the brain, they are nature's most valuable gift to man. 

 Very truly does Albrecht Eau say : " All science is 

 sensitive knowledge in the ultimate analysis ; it does 

 not deny, but interpret, the data of the senses. The 

 senses are our first and best friends. Long before 

 the mind is developed the senses tell man what he 

 must do and avoid. He who makes a general dis- 

 avowal of the senses in order to meet their dangers 

 acts as thoughtlessly and as foolishly as the man who 

 plucks out his eyes because they once fell on shameful 

 things, or the man who cuts off his hand lest at any 

 time it should reach out to the goods of his neighbour." 

 Hence Feuerbach is quite right in calling all philo- 

 sophies, religions, and systems which oppose the 

 principle of sense-action not only erroneous, but 

 really pernicious. Without the senses there is no 

 knowledge — "Nihil est in intellectu, quod nonfuerit in 

 senm," as Locke said. Twenty years ago I pointed 

 out, in my chapter " On the Origin and Development 

 of the Sense-Organs," 1 the great service of Darwinism 

 in giving us a profounder knowledge and a juster 

 appreciation of the senses. 



The thirst for knowledge of the educated thinker is 

 not contented with the defective acquaintance with 

 the outer world which is obtained through our imperfect 

 sense-organs. He endeavours to build up the sense- 

 impressions which they have brought him into valuable 

 knowledge. He transforms them into specific sense- 

 perceptions in the sense-centres of the cortex of the 

 brain, and combines them into presentations, by 

 association, in the thought-centres. Finally, by a 

 further concatenation of the groups of presentations 



1 Collected Popular Lectures ; Bonn, 1878. 



