THE HELLENIC PERIOD 47 



and not-Being must be admitted, for without empty 

 space movement is inconceivable ; if movement exists, 

 empty space also exists. On the other hand, to enable 

 particular movements to be effected everywhere, 

 empty space must penetrate and divide Being. But 

 this division cannot go on indefinitely or Being would 

 be annihilated. It results therefore that all bodies 

 must be composed of ultimate elements or atoms. 

 From a metaphysical point of view, these atoms 

 possess all the properties attributed by the Eleatics 

 to Being. They exist from all eternity, they are quite 

 complete and hence indivisible ; they are absolutely 

 simple, without any internal property which would 

 distinguish them qualitatively from one another. 

 However, they differ physically in form and magnitude, 

 and this is why the natural bodies resulting from their 

 combination appear to us so varied. The atoms have, 

 moreover, a weight which is proportional to their 

 magnitude. According to Burnet, this property exists 

 in a relative sense, for it does not appear in an isolated 

 atom. The lightness and heaviness of the atoms is 

 only due to a whirling collective movement. 1 Under 

 these conditions natural phenomena are easily 

 explained. Change, birth, and death result from the 

 combination or dissociation of atoms. Everything 

 is done in a purely mechanical manner, and where we 

 believe we discern a distant action, there is an inter- 

 mediate medium which transmits the action. Further, 

 to account for the perceptions of the senses, we must 

 distinguish between the primary or objective qualities 

 (weight, density, hardness) and the secondary qualities 

 (colour, taste) which depend upon our manner of per- 

 ception. On this atomic theory is based the explana- 

 tion given by the school of Abdera of the formation and 

 structure of the world. Unfortunately, having once 

 postulated the whirling movement and the combination 



1 8 Burnet, Aurore, p. 396. 



