SKEPTICISM AND IDOLATRY 195 



observed more and more, and generalized less and 

 less." 



" It is often said experiments must be made without 

 a preconceived idea. That is impossible. Not only 

 would it make all experiment barren, but that would 

 be attempted which could not be done. Everyone 

 carries in his own mind his own conception of the 

 world, of which he cannot so easily rid himself. We 

 must, for instance, use language; and our language is 

 made up only of preconceived ideas and cannot be 

 otherwise. Only these are unconscious preconceived 

 ideas, a thousand times more dangerous than the 

 others." 



And he goes on to show how barren would be the 

 mere accumulation of experimental facts, and how 

 the master minds group them into generalizations and 

 laws which make them fit for use. Out of complexity 

 they achieve simplicity and order. And he warns us 

 that even in this true phase of science, lurk the dangers 

 of preconceived ideas, and of inaccuracy of expression. 

 Having pointed out the proper path, he then enters the 

 more debatable field of hypothesis: 



" All generalization," he says, " is a hypothesis. 

 Hypothesis, then, has a necessary role that no one has 

 ever contested. Only, it ought always, as soon as pos- 

 sible and as often as possible, to be subjected to verifi- 

 cation. And of course if it does not stand this test it 

 ought to be abandoned without reserve. This is what 



