72 BULLETIN OF THE 



can only be effected within the substance of the living protoplasm 

 of the animal that assimilates this food. It is not effected by the 

 chemistry of digestion, that merely makes peptone of the pro- 

 toplasm ; merely makes it soluble enough to pass into the substance 

 of the protoplasmic masses that are to appropriate it. These con- 

 siderations, then, would seem to show that the material, protoplasm, 

 cannot be rightly believed to be of itself the cause and essence of 

 life. 



If I should pause here, it seems to me that I should have brought 

 forward adequate reasons for believing in the existence of a vital 

 principle. But I cannot pause here. Beyond and above all this 

 there is another great group of phenomena peculiar to living beings — 

 a group of phenomena conceruing which, in my own individuality, I 

 have knowledge at least as positive as any I possess of the existence 

 of force, and which I am led, by a logic quite as convincing as that 

 by which any general proposition with regard to the external world 

 is proven, to believe exists in like kind and degree in the case of 

 my fellow-man. I refer to the phenomena of the perceiving, emo- 

 tional, willful, reasoning human mind. Into the argument that 

 makes it highly probable that a similar but less and less perfect 

 mind exists in the animal world, and identifies with mind the sensi- 

 bility of the lowest animal forms, and even that of vegetable proto- 

 plasm, I will not attempt to enter to-night. Mr. Herbert Spencer 

 himself has presented this view with so much ingenuity, that, with- 

 out committing myself to an approval of all his details, I must con- 

 tent myself by referring you to his writings for one of the best 

 discussions of this matter. It will be sufficient for my present pur- 

 pose to close this discourse by the presentation of a few considera- 

 tions in relation to mind as it exists in man. 



For myself I know mind only as a manifestation of life, if indeed 

 it is not the essence of life. But the old doctrine of Epicurus, 

 handed down to us in the poem of Lucretius, that in some way or 

 fashion mind is produced by the clashing together of the atoms, has 

 been boldly revived of late years, and transmuted into a form more 

 plausible to modern thought, although just as unsupported by any 

 actual knowledge of facts. 



No one has done this more boldly or more cleverly than Mr. 

 Herbert Spencer has done in his First Principles, and of course you 

 are all familiar with the ingenious argument, in favor of this view, 

 which runs through that masterly work. It would be, from many 



