362 THE CONSERVATION OF FORCE. 



former be contained in it ; that however well or perfectly the 

 definition may include and represent the state of things com 

 monly considered under it, that state or result is only partial, 

 and must not be accepted as exhausting the power or being 

 the full equivalent, and therefore cannot be considered as 

 representing its whole nature ; that, indeed, it may express only 

 a very small part of the whole, only a residual phenomenon, 

 and hence give us but little indication of the full natural truth. 

 Allowing the principle its force, we ought, in every hypothe 

 sis, either to account for its consequences by saying what the 

 changes are when force of a given kind apparently disappears, 

 as when ice thaws, or else should leave space for the idea of 

 the conversion. If any hypothesis, more or less trustworthy 

 on other accounts, is insufficient in expressing it or incompat 

 ible with it, the place of deficiency or opposition should be 

 marked as the most important for examination, for there lies 

 the hope of a discovery of new laws or a new condition of 

 force. The deficiency should never be accepted as satisfac 

 tory, but be remembered and used as a stimulant to further 

 inquiry ; for conversions of force may here be hoped for. 

 Suppositions may be accepted for the time, provided they are 

 not in contradiction with the principle. Even an increased or 

 diminished capacity is better than nothing at all, because such 

 a supposition, if made, must be consistent with the nature of 

 the original hypothesis, and may, therefore, by the application 

 of experiment, be converted into a further test of probable 

 truth. The case of a force simply removed or suspended, 

 without a transferred exertion in some other direction, appears 

 to me to be absolutely impossible. 



If the principle be accepted as true, we have a right to 

 pursue it to its consequences, no matter what they may be. 

 It is, indeed, a duty to do so. A theory may be perfection, 

 as far as it goes, but a consideration going beyond it, is not 

 for that reason to be shut out. We might as well accept our 

 limited horizon as the limits of the world. No magnitude, 



