AND ITS SELF-CONSERVATION. 167 



and of the force that would be required to bring it to 

 rest. 



The moving body itself, then, is a factor which, com- 

 bined with velocity,, constitutes a realized force ; and the 

 greater the velocity the greater the force, so long as the 

 mass of the body remains unchanged. 



But, again, velocity is a product, the formal factors of 

 which are space and time. In other words, velocity is 

 the unity of time and space relations. Evidently also, as 

 a factor of force, velocity has greater value in proportion 

 as the time-element is diminished and the space-element 

 is increased. Thus the kinetic energy of a given body or 

 mass increases, not in the same degree as the velocity of 

 such mass increases, but in a ratio corresponding to the 

 square of the velocity. 



Here, then, a new phase of force develops, the force of 

 motion itself. For momentum, or quantity of motion, is 

 the product of mass and velocity, and a moving body is 

 nothing else than a certain mass possessing a certain 

 velocity. Motion, therefore, is not something apart from 

 force. It is just force itself in realized form. 



Let us next recall the fact, already developed, that the 

 abstract phases of attraction and repulsion are but mere 

 vague pull and push in the realm of " matter." And let 

 us also recall the further fact that has come to light in 

 the course of our inquiry: that it could be only through 

 the spontaneous element of self-activity necessarily im- 

 plied in the totality of the World-Energy, as self-meas- 

 ured, that aggregations of force-centers could take place 

 at all. 



Putting these two facts together, it is evident that not 

 only is motion inevitable as a state of all bodies, but that 



