22 INTRODUCTION 



seemed to him to arise from an inadequate conception of 

 substance, and the task he set himself was that of 

 deepening the current notion of substance, or, as he him- 

 self would have put it, finding a better hypothesis than 

 that which had satisfied his Cartesian predecessors. 



Stated in another way the problem is : How are we to 

 interpret the relation of whole and parts so that the 

 continuity or complete unity of the whole shall not be in 

 conflict with the definiteness or real diversity of the 

 parts ? To say that the whole is continuous or really one 

 seems to mean that, if it is divisible at all, it is infinitely 

 divisible. If it were not infinitely divisible, it would 

 consist of insoluble ultimate elements, and would thus be 

 discontinuous. Accordingly, if the whole be really con- 

 tinuous there seem to be no fixed boundaries or lines of 

 division within it, that is to say, no real, but only 

 arbitrary parts \ 



On the other hand, if the whole consists of real parts 

 and not merely possible subdivisions, these parts must 

 be definite, bounded, separate from one another, and 

 consequently the whole which they constitute must be, 

 not a real continuous unity, but a mere collection or 

 arbitrary unity. Nevertheless, we cannot hold either that 

 the whole is real and the parts unreal, or that the parts 

 are real and the whole unreal. 



Quantitative or extensive Notion of Substance held ly Des- 

 cartes and Spinoza, on the one hand, and ly the Atomists 

 on the other. 



The philosophy of Spinoza, with its cardinal principle 

 that * Determination is negation,' practically amounted 

 to an assertion of the unity and continuity of the whole 

 at the expense of the reality of the parts. According to 



1 For instance, the spectrum is continuous. There is no limit 

 to the number of varieties of colour that may be discriminated in 

 the rainbow : the usual division into seven colours is an arbitrary 

 arrangement made by observers. It probably originated in a sug- 

 gested analogy with the musical scale. 



