HISTORY OP THE ATOMIC THEORY. 129 



vacuity, as it is commonly thought, or erroneously supposed, 

 is a more dense body than the gold as gold. But if we con- 

 sider the whole content of the one with that of the other, 

 within the same or equal quantity of expatiation, then are 

 they both equally containing the materia or body." 



This argument will not appear so conclusive to his readers, 

 but it serves well to shew how unsettled were the opinions on 

 matter, when a man of Hooke's high standing spoke in this 

 manner. He could not believe in epicureaa atoms as he 

 called them, and he had as little faith in " the four elements, 

 the three chemical principles, magnetism, sympathy, fermen- 

 tation, alkaly, and acid, and divers other chimeras." The 

 quotation is by no means intended as a specimen of Hooke as 

 a philosopher. Aristotle's aether and the abstract ideas of 

 Plato are still perceptible here in confusing the reason and 

 obliterating the observation. 



When a definite form is given to the minutest particles of 

 bodies, it leads to their indivisibility by a very easy reasoning, 

 but the moment these ideas become vague, or if a prime matter 

 is allowed, taking various forms, or a few elements changing 

 into each other, essentially the same things, then infinite 

 divisibility is more likely to lay hold of the imagination. 



Des Cartes, speaking of the theory of Democritus, says, "it 

 is rejected because he supposed the existence of indivisible 

 corpuscles, because there was a vacuum around each, which 

 could be demonstrated impossible, and because there was 

 weight given to each, whereas no body has it when taken 

 alone, its existence depends on the situation and motion of 

 other bodies."* But he thinks also that natural things might 

 have been made in various ways. We must explain the 

 phenomena as we best can. *' Ita non dubium est, quin sum- 

 mus rerum opifex, omnia ilia quae videmus, pluribus diversis 

 modis potuerit efficere." t He also retained the four elements. 



* Renati Det Cartes, Principia Philosopbiae. Page 219. Amsterdam, 1(377. 



•j- Prop. ccii. 

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