OF THE NEW SYSTEM 335 



conceived as extended and yet without either actual 

 or ideal 11 parts; and if it is so, I do not know what 

 is meant by being extended 12 . I even hold that matter 

 is essentially an aggregate, and consequently that there 

 are always actual parts. Thus it is by reason, and not 

 merely by the senses, that we judge that it is divided, 

 or rather that it is ultimately nothing but a collection 

 [multitude]. I hold it as true that matter (and even each 

 part of matter) is divided into a greater number of parts 

 than it is possible to imagine. And accordingly I often 

 say that each body, however small it may be, is a world 

 of creatures infinite in number. Thus I do not believe 

 that there are atoms, that is to say, parts of matter which 

 are perfectly hard or of invincible solidity ; while, on the 

 other hand, I as little believe that there is a perfectly 

 fluid matter 1S , and my opinion is that each body is fluid 

 in comparison with more solid bodies and solid in com- 

 parison with the more fluid. I am surprised that it is 

 still said that an equal quantity of motion, in the Car- 

 tesian sense, is always conserved ; for I have proved the 

 opposite, and already excellent mathematicians have 

 admitted it. Nevertheless I do not regard the solidity 

 or consistence of bodies as a primary quality, but as 

 a consequence of motion, and I hope that my Dynamics 

 will show in what this consists, as the understanding of 

 my hypothesis will also serve to remove several diffi- 

 culties which' still engage the attention of philosophers. 

 In fact, I believe I can intelligibly answer all the doubts 

 to which the late M. Bcrnier 1 * has specially devoted a 



11 mentales, i. e. thinkable. 



12 The reference is probably to the views of Foucher, who denied 

 that the essence of matter is extension, holding that all our ideas 

 (including those of external objects) are merely modifications of 

 ourselves and that, in order to represent an object, an idea must 

 be like it. See Foucher de Careil, Lettres et Opuscules inedits de Leibniz, 

 Introduction. 



13 Hartsoeker's theory was that the ultimate elements of things 

 are perfectly hard atoms in a perfect fluid, the atoms combined 

 forming tangible bodies, while the fluid transmits light, &c. 



14 Fran9ois Bernier (d. 1688) was more famous as a traveller 



