XVI PKEFACE. 



Leibnitz had shown towards him in reference to it great 

 unfairness and want of candour. Newton always maintained 

 that Leibnitz was the aggressor in this dispute, and that he 

 had, by his language in the Leipsic Acts, covertly accused him 

 of plagiarism, whereas he might have known from the corre- 

 spondence that formerly took place between them, that Newton's 

 method was in his possession long before he himself became 

 acquainted with the Differential Calculus. 



On the other hand Leibnitz, without avowing himself the 

 author of the article in the Leipsic Acts, denied that it really 

 bore the meaning attributed to it by Newton, and maintained 

 that Newton had either been deceived by a false friend into 

 imagining that he had been accused of plagiarism, or else that 

 he was not sorry to find a pretext for attributing to himself the 

 invention of the new Calculus, contrary to the avowal he had 

 made in the Scholium in the 1st Edition of the Principia. 



From a paper by Leibnitz, which has been published by 

 Dr Gerhardt, it appears that the article in the Leipsic Acts, of 

 which Newton complained, was really written by Leibnitz, and it 

 also seems probable that the ambiguity of its language was not 

 unintentional. We cannot wonder, then, that Newton, firmly 

 believing that Leibnitz had charged him with plagiarism, 

 should have experienced a strong feeling of resentment, and 

 should have been induced to retort the charge upon his accuser 1 . 

 It was not unnatural that this embittered feeling should still 

 survive even after the death of Leibnitz. 



, It is clear from these Portsmouth papers that Newton 

 believed that Leibnitz, during his second visit to England in 

 October 1676, had obtained access to his MS. entitled De 

 Analysi per Equationes numero terminorum infinitas, which 

 was in the hands of Collins, and that he had thus been 

 materially assisted in discovering the Differential Calculus. 

 This tract of Newton's is printed in full in the Commercium 

 Epistolicum, and is there used merely in order to prove 

 Newton's priority to Leibnitz. It is nowhere asserted or even 

 implied in the Commercium that this tract of Newton had ever 



1 In connection with this Newton makes the following quotation from Ovid : 

 "Nee lex est justior ilia, etc." (Artis Amatorice, i. 656.) 



