JURIN V. ROBINS AND PEMBERTON 129 



that Sir Isaac Newton understood by the ultimate 

 sums and ratios of magnitudes no more than the 

 limits of varying magnitudes and ratio's ; and he 

 puts the defence of his method upon this, that the 

 determining any of these limits is the subject of 

 a problem truly geometrical. To insist, that the 

 variable magnitudes and ratio's do actually attain, 

 and exist under these limits, is the very essence of 

 indivisibles " (p. (34)). 



Robins's reply in the August and September, 

 1736, numbers of the Republick of Letters is con- 

 densed in form, yet covers 61 pages, It is im- 

 possible for us to convey an adequate idea of 

 the amount of detail entering in the discussion. 

 Altogether Robins shows greater willingness to 

 admit that Newton's views were different at differ- 

 ent periods in his career, and that even Newton 

 may be guilty of modes of expression that are 

 not free from obscurity. Moreover, Robins speaks 

 in general with greater sincerity than his opponent. 

 But Jurin proves himself the superior of Robins 

 in adhering to a broader and more comprehensive 

 conception of variables and limits. 



Pemberton enters the Debate 

 137. At this stage a new party enters the debate 

 — Henry Pemberton, who had studied medicine and 

 mathematics at Leyden and Paris, had been a friend 

 of Newton, and had edited the third edition of the 

 Principia. In an article follo wing the one of Robins 

 in the '' Appendix " (August and September 1736), 



9 



