NATURE'S INSURGENT SON 65 



gists would have led Lord Kelvin to perceive that those whom 

 he cites are but a trifling percentage of the whole. I do not 

 myself know of any one of admitted leadership among modern 

 biologists who is showing signs of ' coming to a belief in the 

 existence of a vital principle.' 



" Biologists were, not many years ago, so terribly hampered 

 by these hypothetical entities ' vitality,' 'vital spirits,' 'anima 

 animans,' ' archetypes,' ' vis medicatrix,' * providential arti- 

 fice,' and others which I cannot now enumerate that they are 

 very shy of setting any of them up again. Physicists, on the 

 other hand, seem to have got on very well with their proble- 

 matic entities, their * atoms ' and ' ether,' and ' the sorting 

 demon of Maxwell.' Hence, perhaps, Lord Kelvin offers to 

 us, with a light heart, the hypothesis of a * a vital principle ' to 

 smooth over some of our admitted difficulties. On the other 

 hand, we biologists, knowing the paralysing influence of such 

 hypotheses in the past, are as unwilling to have anything to do 

 with ' a vital principle,' even though Lord Kelvin erroneously 

 thinks we are coming to it, as we are to accept other strange 

 ' entities ' pressed upon us by other physicists of a modern 

 and singularly adventurous type. Modern biologists (I am 

 glad to be able to affirm) do not accept the hypothesis of * tele- 

 pathy ' advocated by Sir Oliver Lodge, nor that of the intru- 

 sions of disembodied spirits pressed upon them by others of 

 the same school. 



" We biologists take no stock in these mysterious entities. 

 We think it a more helpful method to be patient and to seek 

 by observation of, and experiment with, the phenomena of 

 growth and development to trace the evolution of life and of 

 living things without the facile and sterile hypothesis of *a 

 vital principle.' Similarly, we seek by the study of cerebral 

 disease to trace the genesis of the phenomena which are sup- 

 posed by some physicists who have strayed into biological 

 fields to justify them in announcing the 'discovery' of 'tele- 

 pathy ' and a belief in ghosts." 



