4 46 VRA GMENTS OF SCIENCE. 



who held that " tlie man who readily contradicts, and uses 

 many words, is unfit to learn anything truly right.'* He 

 is said to have discovered and educated Protagoras the 

 Sophist, being struck as much by the manner in which 

 he, being a hewer of wood, tied up his faggots, as by the 

 sagacity of his conversation. Democritus returned poor 

 from his travels, was supported by his brother, and at 

 length wrote his great work entitled " Diakosrnos," which 

 he read publicly before the people of his native town. He 

 was honored by his countrymen in various ways, and died 

 serenely at a great age. 



The principles enunciated by Democritus reveal his 

 uncompromising antagonism to those who deduced the 

 phenomena of nature from the caprices of the gods. They 

 are briefly these: 1. From nothing comes nothing. Noth- 

 ing that exists can be destroyed. All changes are due to 

 the combination and separation of molecules. 2. Nothing 

 happens by chance; every occurrence has its cause, from 

 which it follows by necessity. 3. The only existing things 

 are the atoms and empty space; all else is mere opinion. 



4. The atoms are infinite in number and infinitely various 

 in form; they strike together, and the lateral motions and 

 whirlings which thus arise are the beginnings of worlds. 



5. The varieties of all things depend upon the varieties of 

 their atoms, in number, size and aggregation. 6. The soul 

 consists of fine, smooth, round atoms, like those of fire. 

 These are the most mobile of all: they interpenetrate the 

 whole body, and in their motions the phenomena of life 

 arise. 



The first five propositions are a fair general statement 

 of the atomic philosophy, as now held. As regards the 

 sixth, Democritus made his finer atoms do duty for the 

 nervous system, whose functions were then unknown. The 

 atoms of Democritus are individually without sensation; 

 they combine in obedience to mechanical laws; and not 

 only organic forms, but the phenomena of sensation and 

 thought, are the result of their combination. 



That great enigma, "the exquisite adaptation of one 

 part of an organism to another part, and to the conditions 

 of life," more especially the construction of the human 

 body, Democritus made no attempt to solve. Empedocles, 

 a man of more fiery and poetic nature, introduced the 

 notion of love and hate among the atoms, to account for 



