36 INTRODUCTION 



As the Monads are purely intensive centres or units, 

 each must be absolutely exclusive of all others. Not 

 being quantitative, they are simple, in the sense of 

 having no parts 1 ; and thus no one Monad can include 

 another. Further, no Monad can really influence another 

 or produce any change in it. For that would mean 

 a transference of quality from one to the other. But 

 as the quality of a substance, being its very essence, is 

 inseparable from it, such a transference is impossible 2 . 

 The Monads are also real ultimate elements, because, 

 being entirely non- quantitative, they cannot have been 

 formed out of any combination of simpler elements, nor 

 is it possible in any way to dissolve them, as they are 

 without parts 3 . The point which is at once real and 

 indivisible has thus (Leibniz thinks) been found in the 

 Monad, as contrasted, on the one hand, with the mathe- 

 matical point of Descartes, which is indivisible only 

 when it ceases to be real, and, on the other hand, with 

 the physical point of the Atomists, which, if it is real, 

 must always be divisible l . 



>L The Identity of Indiscernibles and the Law of Continuity. 



The indivisible having thus been established, there 

 remains the question of continuity and the infinite. As 

 we have seen, a quantitative continuum cannot have 

 indivisible parts. But, as the actual indivisible elements 

 of reality are essentially perceptive, real continuity must 

 also be a continuity of perception. As each Monad is 

 a part or element of the universe, in the sense that each 

 represents it or reflects it as in a mirror from some 

 particular angle, in some special aspect, the whole must 



perception and appetition, although we do not distinctly know 

 the imperceptible elements of the confused perceptions, by which 

 the imperceptible elements of bodies are expressed.' Epistola ad 

 Bierlingntm (1711) (E. 678 a ; G. vii. 501). 



1 Monadology, i. 2 Ibid. 7. 



3 Ibid. 3-6. 



* As to the contrast between Leibniz's view of substance and 

 that of Locke, see Locke's Essay, Fraser's ed, . vol. i. pp. 399 sqq. 



ty 



