THE MULTIPLICATION OF EFFECTS. 469 



When, from unlikeness between the effects they produce 

 on consciousness, we predicate unlikeness between two ob- 

 jects, what is our warrant? and what do we mean by the 

 unlikeness, objectively considered? Our warrant is the per- 

 sistence of force. Some kind or amount of change has been 

 wrought in us by the one, which has not been wrought by 

 the other. This change we ascribe to some force exercised 

 by the one which the other has not exercised. And we have 

 no alternative but to do this, or to assert that the change had 

 no antecedent; which is to deny the persistence of force. 

 Whence it is further manifest that what we regard as the 

 objective unlikeness is the presence in the one of some force, 

 or set of forces, not present in the other something in the 

 kinds or amounts or directions of the constituent forces of 

 the one, which those of the other do not parallel. But now 

 if things or parts of things which we call different, are those 

 of which the constituent forces differ in one or more re- 

 spects; what must happen to any like forces, or any uniform 

 force, falling on them ? Such like forces, or parts of a uni- 

 form force, must be differently modified. The force which 

 is present in the one and not in the other, must be an element 

 in the conflict must produce its equivalent reaction; and 

 must so affect the total reaction. To say otherwise is to say 

 that this differential force will produce no effect; which is 

 to say that force is not persistent. 



I need not develop this corollary further. It manifestly 

 follows that a uniform force, falling on a uniform aggre- 

 gate, must undergo dispersion; that falling on an aggregate 

 made up of unlike parts, it must undergo dispersion from 

 each part, as well as qualitative differentiations ; that in pro- 

 portion as the parts are unlike, these qualitative differentia- 

 tions must be marked ; that in proportion to the number of 

 the parts, they must be numerous ; that the secondary forces 

 so produced, must undergo further transformations while 

 working equivalent transformations in the parts that change 

 them; and similarly with the forces they generate. Thus 



