CHAPTEE Y. 



THE CONTINUITY OF MOTION. 



55. ANOTHEE general truth of the same order with the 

 foregoing, must here be specified. Like the Indestructibil- 

 ity of Matter, the Continuity of Motion, or, more strictly, of 

 that something which has Motion for one of its sensible 

 forms, is a proposition on the truth of which depends the 

 possibility of exact Science, and therefore of a Philosophy 

 which unifies the results of exact Science. Motions, visible 

 and invisible, of masses and of molecules, form the larger 

 half of the phenomena to be interpreted; and if such mo- 

 tions might either proceed from nothing or lapse into noth- 

 ing, there could be no scientific interpretation of them. 



This second fundamental truth, like the first, is by no 

 means self-evident to primitive men or to the uncultured 

 among ourselves. Contrariwise, to undeveloped minds the 

 opposite seems self-evident. The facts that a stone thrown 

 up soon loses its ascending motion, and that after the blow 

 its fall gives to the Earth, it remains quiescent, apparently 

 prove that the principle of activity* which the stone mani- 

 fested may disappear absolutely. Accepting, without criti- 

 cism, the dicta of unaided perception, to the effect that 

 adjacent objects put in motion soon return to rest, all men 

 once believed, and most believe still, that motion can pass 

 into nothing; and ordinarily does so pass. But 



* Throughout this Chapter I use this phrase, not with any metaphysical 

 meaning, but merely to avoid foregone conclusions. 



