NATURE AND NURTURE 69 



Berkeley's assertion, that "the work of science is to unravel our 

 prejudices and mistakes, untwisting the closest connections, distin- 

 guishing things that are different; instead of confused and per- 

 plexed, giving us distinct views; gradually correcting our judgment 

 and reducing it to a philosophical exactness." 



Physical exercise corrects our bodily movements, and reduces 

 them to exactness, by giving us distinct movements, instead of 

 confused and perplexed ones ; but we are unable to believe that 

 training gives us any new muscles, and their fitness for improve- 

 ment by exercise is 'itself an adaptation which calls for explana- 

 tion. 



If Berkeley is right, as he seems to me to be, and if what we 

 call natural knowledge is no more than the correction of our 

 judgment and its reduction to exactness, it seems clear that 

 knowledge no more accounts for our judgment than training ac- 

 counts for our muscles, and that physical culture and mental cult- 

 ure are, in this respect, exactly alike. 



The modern zoologist, who reflects upon the phenomena of 

 nature, is forced, like all who have gone before him, to consider 

 anew the ancient and difficult question whether there are "innate 

 ideas"; and, even if his success be slight, and his conclusions 

 indefinite, he may, perhaps, make use of his acquaintance with 

 living things to focus the point at issue, and to show that this 

 may be, in part at least, a matter of words and definitions. 



" It is Plato's remark, in his ' Theaetetus,' that while we sit still 

 we are never the wiser, but going into the river, and moving up and 

 down, is the way to discover its depths and shallows. If we exercise 

 and bestir ourselves, we may even here discover something." 1 



So far as it concerns the zoologist, the question seems to be this : 

 Is it something we find in our nature, or something we discover in 

 the outer world, which justifies our confidence in our mental states 

 and in our responsive actions ; or may there not be a sense in which 

 each point of view is the true one ? 



I have tried to show, page 59, that, while the responsive activities 

 of living things do not take place until they- are called forth by a 

 proper stimulus, the things they do under stimulus are no more than 

 their organic mechanism would lead us to expect ; and that there 



1 Berkeley, " Siris," p. 367. 



