THE FABRIC OF MATTER 13 



or be destroyed, and every change consists only 

 of a combination or separation. 



" (2) Nothing is accidental ; there is a reason 

 and necessity for everything. 



" (3) All except atoms and vacua is reason, and 

 not existence. 



" (4) The atoms, which are infinite in number 

 and form, constitute the visible universe by their 

 motion, impact, and consequent revolving motion. 



"(5) The variety of objects depends only on a 

 difference in the number, form, and order of the 

 atoms of which they are formed, and not upon 

 a qualitative difference of their atoms, which only 

 act upon each by pressure and impact. 



" (6) The spirit, like fire, consists of minute, 

 spherical, smooth, and very mobile and all- 

 penetrating atoms, whose motion forms the 

 phenomenon of life." 



Much the most important of these propositions 

 are the fourth and fifth. Though quite empiric 

 and intuitive, they yet were a forecast of the 

 principles and hypotheses on which modern science 

 is based, and they have influenced scientific thought 

 for over two thousand years, and have become only 

 more firmly established and more illuminating with 

 the progress of scientific discovery and the develop- 

 ment of scientific method. Only, indeed, in quite 

 recent years has their full philosophic meaning 



