442 SCIENCE PROGRESS 



regarded as purposive if we orientate our minds in a certain 

 way towards it; but all natural events are none the less me- 

 chanical, physical, chemical, etc., in their causes and mode of 

 working. So, in referring to the teleological harmony of 

 the bodily functions, Dr. Haldane is only naming one of the 

 results which most biologists attribute to the blind operation of 

 natural selection. It is a striking example only because of the 

 extreme perfection of the adaptation between the organs of 

 the body. Not the extremest vitalist would deny that natural 

 selection, a mechanical factor, may bring about adaptation : 

 that the fauna of a country is adapted to the climate for the 

 simple reason that non-adapted varieties could not live. And 

 if adaptation of a simple kind be thus mechanically explicable, 

 if adaptation itself be a mere mechanical event, then vitalists 

 cannot look to it for arguments against mechanism. 



Dr. Haldane's second argument is a very common one. 

 " The conceptions of physics and chemistry are insufficient to 

 enable us to understand physiological phenomena": hence we 

 must pass to some vitalistic theory. That argument has lain 

 at the base of every myth since the world began. Here is a 

 strange event : we do not see how natural forces could have 

 compassed it: therefore ghosts did it. It is the primitive ten- 

 dency to attribute animism to whatever we cannot understand. 

 I shall comment later upon this argument in connexion with 

 the work of Driesch. With reference to Dr. Haldane, I need 

 only refer further to his statement that biology " deals with 

 a deeper aspect of reality" than physics and protest once 

 more against the introduction of metaphysical conceptions into 

 science. "Reality" is not a stratified deposit into which we 

 may penetrate more or less deeply : all scientific truths are 

 equally real for the man of science, those of physics not less so 

 than those of biology. 



The Views of Hans Driesch 



One of the most frequently quoted of all authorities in favour 

 of vitalism is Hans Driesch, whose Science and Philosophy of the 

 Organism is a deliberate attempt to re-establish that discredited 

 doctrine on a secure foundation. It will be necessary, there- 

 fore, to devote some space to the examination of his three proofs 

 of vitalism. 



