158 GALILEO AND HIS JUDGES. 



system from a simple though strong probability, a 

 question on which at any rate something might be 

 said for and against it, to a probability of almost 

 overwhelming force ; for it not only showed how the 

 heavenly bodies moved, but it explained the cause of 

 their motions, and in a word furnished the key that 

 unlocked the arcana of Nature. When you came to 

 know not only how the Moon and the planets moved, 

 but the law which regulated their movements, and 

 when you found that all fitted into one harmonious 

 whole (at least with some minor exceptions), it was 

 not easy to refuse assent to a theory supported by 

 such powerful evidence. 



Yet in saying this we are perhaps rather viewing 

 the question from our present standpoint, than as a 

 contemporary would have done. As a matter of fact, 

 Newton's hypothesis, though eagerly received in Eng- 

 land, met with a long opposition on the Continent, 

 and particularly in France, where Descartes' theory 

 of vortices reigned supreme for many years. It must 

 not be supposed that these Cartesian philosophers were 

 anti-Copernicans ; far otherwise, only they accounted 

 for the celestial motions in a different way from 

 Newton, and, as every one now admits, in a wrong 

 way. 



I have already remarked that there were some 

 apparent difficulties in the application of the law of 

 universal gravitation to all the heavenly bodies, and 

 that these have been removed by subsequent calcu- 

 lation. One of these difficulties, if indeed it could 



