PRINCIPLES OF NATURE AND GRACE 409 



natural machine, which is a machine not only as a whole, 

 but also in the smallest parts of it that can come into 

 observation ". Since the world is a, plenum all things are 

 connected together and each body acts upon every other, 

 more or less, according to their distance, and each, through 

 reaction, is affected by every other. Hence it follows that 

 each Monad is a living mirror, or a mirror endowed with 

 inner activity v ~, representative of the universe, according 

 to its point of view, and as subject to rule as is the 

 universe itself. /And the_ perceptions in the Monad are 

 produced one from another according to the laws of desires 

 [appetits] or of the final causes of good and evil, which con- 

 sist in observable perceptions, regular or irregular, as, on 

 the other hand, the changes of bodies and external pheno- 

 mena are produced one from another according to the 

 laws of efficient causes, that is to say, of motions 13 . Thus 

 there is a perfect harmony between the perceptions of the 

 Monad and the motions of bodies, a harmony pre-estab- 

 lished from the beginning between the system of efficient 

 causes and that of final causes. And it is in this way 

 that soul and body are in agreement and are physically 

 united, while it is not possible for the one to change the 

 laws of the other u . 



^4. Each Monad, with a particular body, forms a living 

 substance. Thus not only is there everywhere life, 

 accompanied with members or organs, but there is also 



11 Cf. Monadology, 64. 



12 ' This " mirror " is a figurative expression ; but it is suitable 

 enough and it has already been employed by theologians and 

 philosophers, when they spoke of a mirror infinitely more perfect, 

 namely, the mirror of the Deity, which they made the object of the 

 beatific vision.' Lettre a Masson (1716) (G. vi. 626). 



15 Ultimately, motions and desires (appetits) are different degrees 

 of the same thing, viz. appetition, or the passage from one con- 

 scious or unconscious perception to another. The unconscious 

 appetition is motion or efficient cause, not setting before itself an 

 end, while the conscious appetition or desire does set before itself 

 an end of good or evil, i. e. a final cause. 



14 Cf. Monadology, 78 sqq. 



