DESCARTES 



but he was strongly attracted by mathematics, which 

 he was destined to greatly improve. His biographer, 

 Biot, states : 



"His first endeavor, on leaving school, was to 

 erase from his understanding, as far as possible, all 

 that was uncertain in its nature, and thenceforward 

 to admit only that which was capable of being proved 

 by reason and demonstration. He thus invented 

 that system of doubt and of examination which has 

 since been the first principle of all positive science. 

 We do not now appreciate the value of such an 

 effort; for we have grown up under its teaching, so 

 that it seems reasonable and natural. But at the 

 time of Descartes the Aristotelian Philosophy ruled 

 despotically over all minds. It was considered in 

 the Colleges the necessary support of all religion. 

 To doubt Aristotle was not only a novelty, but a 

 crime. What strength of mind must this young man 

 of nineteen have possessed to have hoped to reform 

 the judgment of all. It is not less astonishing that 

 Descartes appears at that time to have already made 

 his most brilliant mathematical discoveries. 



" He thought it was not yet the time to publish his 

 new ideas. He determined to enter the Army, 

 which would give him the opportunity to travel and 

 to see the world. He served as a Volunteer in the 

 troops of Holland and of the Duke of Bavaria. 



63 



