34 THE ADVANCE OF SCIENCE 



facts which is absurdly called ' Baconian ' 

 induction. But anyone who is practically 

 acquainted with scientific work is aware 

 that those who refuse to go beyond fact, 

 rarely get as far as fact ; and anyone who 

 has studied the history of science knows 

 that almost every great step therein has 

 been made by the 'anticipation of Na- 

 ture,' that is, by the invention of hy- 

 potheses, which, though verifiable, often 

 had very little foundation to start with ; 

 and, not unfrequently, in spite of a long 

 career of usefulness, turned out to be 

 wholly erroneous in the long run. 

 Fruitful The geocentric system of astronomy, 



use of an . . 



hypoth- with its eccentrics and its epicycles, was 

 ^vhen L an hypothesis utterly at variance with 

 wrong, jp ac ^ wn i cn nevertheless did great things 

 for the advancement of astronomical 

 knowledge. Kepler was the wildest of 

 guessers. Newton's corpuscular theory 

 of light was of much temporary use in 

 optics, though nobody now believes in it ; 



