GENERAL PRINCIPLES 37 



be the infinite totality of Monads, representing the 

 universe from every possible point of view. And thus, 

 while the Monads are entirely separate from one another, 

 each must represent the universe in a way which differs 

 to the least possible extent from the representation given 

 by some other. No two Monads (and a fortiori no two Y 

 things, which are all aggregates of Monads; can be exactly y 

 the same : no thing can have a merely numerical differ- *""" 

 ence from another. The Monads are essentially non- 

 quantitative, and number by itself is merely a measure 

 of quantity. The Monads differ from one another in 

 quality or intension alone, so that two Monads not 

 differing in quality are impossible. This is the doctrine 

 of Leibniz which is usually called the 



cerniblesV It is simply his law of continuity in a ^ 

 negative form. The number of Monads must be in- 

 finite 2 : otherwise the universe would not be represented 

 from every possible point of view, and would thus be 

 imperfect. But if the number of Monads is infinite, and 

 if every Monad differs in quality from every other, then 

 the Monads must be such that they might be considered 

 as a series, each term or member of which differs from 

 the next by an infinitely small degree of quality, i. e. by 

 a degree of quality less than any which can be assigned. 1> - 

 Leibniz explains his principle of continuity in a letter y 

 quoted by his biographer, Guhrauer 3 . *I think, then,' 



1 < There are no two indiscernible individuals. A clever gentle- 

 man of my acquaintance, talking with me in presence of Mme. the 

 Electress, in the garden of Herrenhausen, was of opinion that he 

 could quite well find two leaves entirely alike. Mnie. the Electress 

 would not believe it, and he spent a long time vainly seeking them. 

 Two drops of water or of milk, looked at through a microscope, will 

 be found discernible. This is an argument against atoms, to which, 

 no less than to the void, the principles of true metaphysic are 

 opposed ... To suppose two indiscernible things is to suppose the 

 same thing under two names.' IF"* 5 Lettre a Clarke, 4 and 6 

 (E. 755 b, 756 a ; G. vii. 372). Cf. Nouveaux Essais, bk. ii. ch. 27, 3 

 (E. 277 b ; G. v. 214). 



2 Du Bois-Reymond compares the infinite series of Monads to 

 the ordinates of a curve, which grow from nothing to infinity. 



3 G. W. F. von Leibnitz, eine Biographic, vol. i., Anmerkungen, p. 32. 



