230 Force y Energy, and Will 



We shall naturally at first be disposed to think that a 

 conception based upon such discoveries, and which has been 

 propagated energetically by thinkers so distinguished, must 

 be a valid one, and that the new phraseology must therefore 

 be a real improvement. Now I should be the last to under- 

 rate either the value of the physical discoveries of equivalence 

 between activities or the merit of the illustrious discoverers. 

 Deference is most justly due to the expressed opinions of 

 such men, and we may well hesitate before venturing to 

 regard as mistakes what they appear to deem so important 

 and so true. We have, however, but to consult the history 

 of a few years back to find sufficient evidence that the most 

 distinguished leaders of thought may fall into the most 

 elaborate speculative errors. Hegel and Schelling, in their 

 day, were men at least as eminent and as esteemed as any of 

 our living philosophers. Yet who now beHeves that any 

 profound truth lies hid in the judgment that 'being and not- 

 being are identical,' enunciated by the former, or considers 

 that the biological speculations of the latter have any real 

 scientific value ? On the other hand, there are not a few 

 who feel no trifling grudge against these writers for having 

 led them through the fame of their ^vritings to expend 

 much time in acquiring a knowledge of systems which 

 when acquired proved empty and worthless. I should be 

 very sorry to be thought wanting in respect for the labours 

 and fruitful speculations of the veteran Professor Schwann, 

 who will ever deserve the gratitude no less than the admira- 

 tion of biologists ; but fully recognising his merits, we may 

 yet ask. Who now accepts his cell theory as put forward by 

 him ? 



Fortified with such reflections, we need not shrink from 

 respectfully questioning the conclusions of the most distin- 

 guished physicists or the most widely accepted philosophers 

 of to-day, even if it were not the rule both in science and 



