ARCHELAFS, AND HERACL1TUS. 4jj)0 



of mathematical and physical science on the basis 

 of established principles. With the sages of 

 the oriental nations, he maintained the existence 

 of an omnipresent fiery aether, as the primary 

 efficient cause of motion throughout the universe ; 

 and which he termed avroicivriTov, for the purpose 

 of representing its self-moving power. According 

 to Cicero, he also regarded it as the soul or mind 

 of universal nature, because he conceived that a 

 self-moving principle, wherever it exists, must 

 have intelligence. (De Natura Deorum, lib. i.) 

 Aristotle termed it KIV^TIKOV, as indicating its 

 power of giving motion to other bodies. (De 

 Anima, lib. i. c. 2.) By the energy of this 

 principle, Thales maintained that the passive 

 elements of matter were reduced to order from a 

 fluid state, and that it is the proximate cause of 

 life in plants and animals. 



In conformity with the above doctrine, Par- 

 menides and Archelaus maintained that heat was 

 the cause of motion, and cold of rest ; or that heat 

 and cold were the first principles of action in 

 nature. Heraclitus also regarded fire as the cause 

 of energy throughout the universe ; and as it 

 seemed to produce all effects in a regular series, 

 in obedience to perfectly wise laws, he conceived 

 that it must be omniscient and divine. 



It has been often asserted by both ancient and 

 modern writers, that Democritus denied the ex- 

 istence of any independent principle as the 



