DEDUCTIVE HABITS. 32,9 



Since the difference is so great between the 

 process of inductive generalization of physical 

 facts, and that of mathematical deduction of 

 consequences, it is not surprising that the two 

 processes should imply different mental powers 

 and habits. However rare the mathematical 

 talent, in its highest excellence, may be, it is far 

 more common, if we are to judge from the history 

 of science, than the genius which divines the 

 general laws of nature. We have several good 

 mathematicians in every age ; we have few great 

 discoverers in the whole history of our species. 



The distinction being thus clearly established 

 between original discovery and derivative specu- 

 lation, between the ascent to principles and the 

 descent from them, we have further to observe, 

 that the habitual and exclusive prosecution of 

 the latter process may sometimes exercise an 

 unfavourable effect on the mind of the student, 

 and may make him less fitted and ready to appre- 

 hend and accept truths different from those with 

 which his reasonings are concerned. We conceive, 

 for example, that a person labours under gross 

 error, who believes the phenomena of the world 

 to be altogether produced by mechanical causes, 

 and who excludes from his view all reference to 

 an intelligent First Cause and Governor. But 

 we conceive that reasons may be shown which 

 make it more probable that error of such a kind 

 should find a place in the mind of a person of 



