AND ITS SELF-CONSERVATION. 141 



spontaneous action, and, hence, a world in which motion 

 can only occur through external impulse; that is, through 

 "impressed forces/' 



The second law expresses positively the externality of 

 the physical world by declaring that whatever motion a 

 body possesses it has received from without ; its motion is 

 always in the direction of, and is directly proportioned to, 

 the impressed forces. 



But the union of these two phases shows also that, 

 after all, no body is moved wholly by external or im- 

 pressed forces. For the body can in reality be acted 

 upon only in so far as it itself presents to the action a 

 corresponding force of reaction. 



Thus, finally, the third law declares in effect absolutely 

 that the externality of nature is, in truth, a completely 

 reflexive externality. The total round of nature presents 

 us with an externality which already bears within it the 

 factor of internality. It may be true that no body is 

 able, apart from other bodies, to change its own state. 

 But there is manifestly a vital, indestructible relationship 

 between body and body, such that change is ceaselessly 

 effected in every body. 



Chemistry, indeed, knows nothing of actions but only 

 of reactions. It is as if one were to say: "The 'atom/ 

 the isolated body, can indeed change its state in no other 

 way than through impressed forces, but in the totality of 

 bodies there is a principle initiative of change. The 

 totality alone is truly active. Particular aspects of the 

 totality are manifested only as reactions, or as mutually 

 balancing phases of the total action/' 



It turns out, then, that these three laws are but 

 the three successively deepening phases of a rational 



