132 WHAT IS LIFE 



not necessarily exhausted ; that new forms may be 

 discovered ; and that if new forms exist, until they 

 are discovered, the Law of Conservation of Energy, 

 as now stated, may in some cases be strictly untrue, 

 though partially and usefully true ; just as it would 

 be untrue, though partially and usefully true, in 

 the theory of machines, if heat were unknown or 

 ignored." 



We may feel perfectly clear from what we know 

 best ourselves from our intimate and everyday 

 experience, namely, conscious human life, and from 

 the processes which take place in living matter, 

 that life or the vital principle does modify the 

 forces, energies, and movements of matter. Is it 

 not perfectly obvious that the war-fever, religious 

 revivals, electoral excitements are all ideas, yet all 

 exercise potent influences over the energies and 

 movements of matter, in the shape of human 

 beings, not to speak of all the material activities 

 which they control ? 



If the arguments in favour of the existence of 

 an energy in living matter which is not to be found 

 amongst the known energies of chemistry or physics 

 are conclusive, as they appear to be to the present 

 writer, and, as he has tried to show, to many men 

 of science whose claims to be heard on this point 

 are far greater than any which he can put forward, 

 then it is quite clear either that the Law of Con- 



