132 THE WORLD-ENERGY 



repulsion. And this not merely within itself, but also with 

 reference to all other bodies. For, as has already been 

 shown, even an atom is a force-center, which is also a 

 force-sphere, extending infinitely and laying hold on each 

 and all other such spheres. 



The relation of distance between any two bodies will 

 therefore depend upon the deeper relation expressed in 

 the algebraic sum of the centripetal and the centrifugal 

 forces constituting the complex relation of the bodies to 

 one another, and which must determine whether they 

 shall approach each other or become more widely sepa- 

 rated from one another. 



Thus every actual change of relation in space between 

 any two bodies is seen to be necessarily nothing else than 

 a manifestation of force. And since the motion can only 

 be a change of relation in distance, or direction, or both, 

 as between two or more bodies, such change resulting 

 from, or rather being itself a manifestation of, the pre- 

 dominance, either of attraction or of repulsion, between 

 them, it is evident that motion cannot be conceived as 

 taking place save in a multiple world of objects. 



It is further evident that no single body possesses 

 within itself alone the power to put itself in motion, as a 

 whole, in any direction whatever. And this implies also 

 that, once put in motion, it can never, of itself, change 

 either the direction or the rate of its motion. 



It would seem, then, that impulse toward motion or 

 hindrance from motion must come from without. And 

 yet, not wholly from without, since the force-relation is 

 ever essentially a mutual one. 



Here, indeed, we have an intimation of the primary 

 condition of all actual motion. We shall see, too, that 



