292 STUDIES IN INSECT LIFE, ETC. 



of the law of gravitation, and his application of 

 it to the explanation of Kepler's laws of planetary 

 motion and of the principal inequalities in the 

 orbital motion of the moon, made him the founder 

 of the science of gravitational astronomy. His 

 discovery of the method of fluxions entitles him 

 to rank with Leibniz as one of the founders of 

 mathematical analysis. All these great discoveries 

 gave rise to long and sometimes acrimonious 

 controversies among his contemporaries, relating 

 both to the subjects themselves and to priority 

 of discovery. In a letter to Halley referring to 

 one of these disputes, Newton writes : 



" Philosophy is such an impertinently litigious 

 lady, that a man has as good be engaged in law- 

 suits, as have to do with her. I found it so 

 formerly, and now I am no sooner come near her 

 again, but she gives me warning." 



His chief work, " Principia," has been described 

 by Dean Peacock as " the greatest single triumph 

 of the human mind."* 



* Newton held the office of President of the Royal Society 

 for the last twenty-five years of his life, a period exceeded 

 only in the case of one President, Sir Joseph Banks, 



