130 THE WORLD-ENERGY 



Evidently, then, all motion is relative, though our 

 knowledge of such motion is in many respects absolute. 

 Among other things, we know, with absolute certainty, 

 that the expression, " absolute motion," is a contradic- 

 tion in terms ; or, in other words, we know absolutely 

 that no motion of a body can be really conceived save 

 as relative to some other body. 



What further is to be known of motion in its gen- 

 eral character has long since been formulated with at 

 least apparent " exactness," or, in other words, with 

 absolute precision. Our next task, then, will be to 

 examine these formulas. 



