Chap, i.] CONSTITUTION OF MATTER. 3 



persed through the limitless void- of the universe, did not furnish 

 a sujfficiently precise account of the constitution of bodies. 

 Epicurus appeared, whose doctrine was so magnificently sung 

 by the great poet Lucretius. He immensely improved the 

 atomic theory of Leucippus and Demociitus by vivifying atoms, 

 and by supposing them endowed with spontaneous movement. 

 From the mobility of atoms resulted their various aggregations 

 and the dissemblances of bodies. According to Epicurus, atoms 

 of necessity mingled together, intertwined, literally caught and 

 clung to each other. A philosopher who had the talent to 

 preach and to propagate in France the atomic theory without 

 seeming to offend the orthodoxy of his epoch, which was still 

 very suspicious, Gassendi, restored to honoui- the atomic doctiine 

 of the ancients. He admits, according to the expression of 

 Epicurus, that "that which is moves in that which is not," 

 that is, that atoms are not in contact, but that they are 

 separated by void spaces. 



Thus then, according to this theory, the world is composed 

 of an innumerable quantity of atoms, mobile, infinitely small, 

 distant from each other. These atoms are in a perpetual state 

 of movement, rushing toward each other, repelling each other, 

 for they have their sympathies and antipathies. It is from 

 the diversity of their affiriities that result their exceedingly 

 diversified modes of grouping and the variety of the external 

 world. It is by their vibrations, their oscillations that they 

 reveal themselves to man by impressing his organs of sense. 

 They have as essential qualities inalterability, eternity. When 

 they gather together, new bodies are formed ; when they dis- 

 aggregate, bodies previously existing dissolve and seem to vanish. 

 They are unhewn stones which have passed, pass, and are 



as man ; that everything consists of atoms, which he also calls ideas, and that 

 nothing else exists, forasmuch as generation cannot arise from that which is 

 not while likewise what exists cannot cease to he, because atoms are so firm 

 that they cannot change nor alter nor suffer." — Plutakoh, Miscellaneous 

 Works: Against the Epicwrean Colotes ; Amyot's translation, Clavier's 

 edition, vol. xx., Paris, 1803. 



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