CHAP. V. 

 *Bfthe various Relations of Terrestrial Being*. 



1 . VV E have seen, that all is relation in the universe* 

 but we have only hitherto taken a distant view of this 

 fruitful truth. We may now approach nearer to it, and 

 bestow our attention on the most interesting particulars. 



The union of souls -to organized bodies, is the source 

 *>f the most abundant and most wonderful harmony that 

 exists in nature. A substance without extension, soli- 

 dity, and form, is united to an extended, solid, and 

 formed substance/ A substance that thinks, and which 

 lias a principle of action in it, is united to a substance 

 void of thought and purely passive. From this surpris- 

 ing connection there springs a reciprocal commerce be- 

 tween the, two substances : a kind of action and re-action, 

 which constitutes the life af organized animated beings. 

 The nerves, being .variously agitated by objects, commu- 

 nicate their motions to the brain, and to these impulses 

 the .perceptions in the soul correspond, which are totally 

 -distinct from the cause that occasions them. 



The rays which proceed from an object strike my op- 

 tic nerve, I have a perception that points out to me the 

 presence of the object. They affect this nerve in a vio- 

 lent manner : I have a sensation which I express by the 

 term of pain. 



The diversity of senses by which the soul receives the 

 .impression of objects, produces a diversity in her per- 

 ceptions and sensations. The sentiments occasioned by 

 the motion of the nerves of sight, differ absolutely from , 

 those that are produced by that of the nerves of hear- 



