THE GREEK ATTITUDE 



nized, and the same unity accomplished, by supposing 

 that life is but a form of matter and motion. This 

 atomistic philosophy was proposed by Leucippus, 

 but the form, in which we know it, was devel- 

 oped by Democritus. This philosopher has hardly 

 received the recognition which he deserves. With no 

 data of experience he conceived and stated a theory 

 of the world by pure deduction and intuition which 

 is still the foundation of modern science. According 

 to Democritus, the elementary substance is not one 

 we can recognize by our senses; it consists of an in- 

 finite number of exceedingly small particles which 

 he calls atoms because they are indivisible. They can 

 differ among themselves only in shape, in order or 

 sequence, and in position. These postulates, according 

 to the Atomists, are sufficient to explain all the di- 

 versities of matter and its phenomena. In order to 

 compound themselves to form the world, the atoms 

 possess a primordial and eternal motion. This motion 

 was of two kinds; the larger atoms drift downwards 

 in straight lines towards what is now the centre of the 

 earth, and thus displace or compel the lighter ones to 

 move upwards; the collisions between these two 

 streams cause them to have lateral movements. In this 

 way, rotations were started which, extending farther 

 and farther, occasioned the formation of worlds. De- 

 mocritus also introduced the idea of a vacuum or 

 empty space between the atoms which has played so 



prominent a role in modern physics. And he gives in 



n4i 3 



