AND ITS SELF-CONSERVATION. 169 



thought from all action of force save that between two 

 bodies mutually attracting each other. 



In such case, the resultant motion must, of course, 

 be literally in the direction of the straight line joining 

 the bodies ; and this could not but terminate in the 

 meeting and fusion of the two bodies unless their 

 inherent elasticity should be of such degree as to cause 

 their rebound from one another, to be once more drawn 

 together and again rebound, and so on ad infinitum. 



On the other hand, however, the recognition of the 

 truth of the universality of the law of gravitation 

 recalls us to a consciousness of the very abstract, incom- 

 plete, and therefore, thus far, untrue representation 

 which we have as yet formed of the actual relation 

 of body to body in space. 



Nevertheless, it can hardly be denied that we have 

 proceeded consistently with the second law of motion in 

 finding the resultant of two directions of the action of 

 force. So that the representation we have thus far 

 formed is doubtless " untrue" only in the sense of being 

 inadequate. 



What remains to be done, then, in this respect is 

 that we shall proceed to the further step of finding 

 the resultant of a third direction of the action of force 

 with the resultant already obtained, and thus gain a 

 clue by which we may approach the conception of 

 something like a complete system of forces the system 

 itself being in perfect equilibrium, while the bodies 

 comprised in the system are in ceaseless motion. 



It will be found, too, that actual motion can never 

 be in a straight line, but rather that it must ever be 

 in curved directions. It is to the consideration of such 

 motion, then, that the next chapter will be devoted. 



