CHAPTER XX. 



THE MULTIPLICATION OF EFFECTS. 



§ 156. To the cause of increasing complexity set forth 

 in the last chapter, we have in this chapter to add another. 

 Though secondary in order of time, it is scarcely secondary 

 in order of importance. Even in the absence of the cause 

 already assigned, it would necessitate a change from the 

 homogeneous to the heterogeneous; and joined with it, it 

 makes this change both more rapid and more involved. To 

 come in sight of it, we have but to pursue a step further, 

 that conflict between force and matter already delineated. 

 Let us do this. 



When a uniform aggregate is subject to a uniform force, 

 we have seen that its constituents, being differently condi- 

 tioned, are differently modified. But while we have con- 

 templated the various parts of the aggregate as thus under- 

 going unlike changes, we have not yet contemplated the un- 

 like changes simultaneously produced on the various parts 

 of the incident force. These must be as numerous and im- 

 portant as the others. Action and re-action being equal 

 and opposite, it follows that in differentiating the parts on 

 which it falls in unlike ways, the incident force must itself 

 be correspondingly differentiated. Instead of being as be- 

 fore, a uniform force, it must thereafter be a multiform 

 force — a group of dissimilar forces. A few illustrations will 

 make this truth manifest. 



A single force is divided by conflict with matter into 

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