Ill SCIENCE AND PSEUDO-SCIENCE 107 



will the form of the orbits, the varying rates of 

 motion of the planets, and the ratio between 

 those rates and their distances from the sun, 

 which must follow by mathematical reasoning 

 from these premisses, agree with the order of 

 facts determined by Kepler and others, or not ? 



Newton, employing mathematical methods 

 which are the admiration of adepts, but which 

 no one but himself appears to have been able 

 to use with ease, not only answered this question 

 in the affirmative, but stayed not his constructive 

 genius before it had founded modern physical 

 astronomy. 



The historians of mechanical and of astronomi- 

 cal science appear to be agreed that he was the 

 first person who clearly and distinctly put forth 

 the hypothesis that the phenomena comprehended 

 under the general name of " gravity " follow the 

 same order throughout the universe, and that all 

 material bodies exhibit these phenomena ; so that, 

 in this sense, the idea of universal gravitation 

 may, doubtless, be properly ascribed to him. 



Newton proved that the laws of Kepler were 

 particular consequences of the laws of motion 

 and the law of gravitation in other words, the 

 reason of the first lay in the two latter. But to 

 talk of the law of gravitation alone as the reason 

 of Kepler's laws, and still more as standing in 

 any causal relation to Kepler's laws, is simply a 

 misuse of language. It would really be interest- 



