SPACE, TIME, MATTER, MOTION, AND FORCE. 



is not less legitimate than the conception of aggregate 

 masses as extended and resistent. The atomic hypothesis, 

 as well as the kindred hypothesis of an all-pervading ether 

 consisting of molecules, is simply a necessary development 

 of those universal forms which the actions of the Unknow- 

 able have wrought in us. The conclusions logically worked 

 out by the aid of these hypotheses, are sure to be in harmony 

 with all others which these same forms involve, and will 

 have a relative truth that is equally complete. 



49. The conception of Motion as presented or repre- 

 sented in the developed consciousness, involves the concep- 

 tions of Space, of Time, and of Matter. A something that 

 moves; a series of positions occupied in succession; and a 

 group of co-existent positions united in thought with the suc- 

 cessive ones these are the constituents of the idea. And 

 since, as we have seen, these are severally elaborated from 

 experiences of force as given in certain correlations, it fol- 

 lows that from a further synthesis of such experiences, the 

 idea of Motion is also elaborated. A certain other element 

 in the idea, which is in truth its fundamental element, 

 (namely, the necessity which the moving body is under 

 to go on changing its position), results immediately from the 

 earliest experiences of force. Movements of different parts 

 of the organism in relation to each other, are the first pre- 

 sented in consciousness. These, produced by the action of 

 the muscles, necessitate reactions upon consciousness in the 

 shape of sensations of muscular tension. Consequently, each 

 stretching-out or drawing-in of a limb, is originally known 

 as a series of muscular tensions, varying in intensity as the 

 position of the limb changes. And this rudimentary con- 

 sciousness of Motion, consisting of serial impressions of 

 force, becomes inseparably united with the consciousness 

 of Space and Time as fast as these are abstracted from fur- 

 ther impressions of force. Or rather, out of this primitive 

 conception of Motion, the adult conception of it is developed 



