PROGRESS 33 



would explain it adequately and without further 

 trouble, forgetting that there must be at least some 

 points of difference between a natural selection pro- 

 ducing a degenerate type and natural selection leading 

 to progress. Some biologists have lumped it, together 

 with all other evolutionary processes which seem to 

 show us a development along predetermined lines, 

 under the head of orthogenesis — the (hypothetical !) 

 tendency of organisms to unfold just one type of 

 hidden potentiality. Bergson has been particularly 

 struck with it : refuses to allow that it can have 

 anything to do with Natural Selection or any deter- 

 minist process, and ascribes it to his elan vital. 



Here, as so often elsewhere, Bergson reveals himself 

 as a good poet but a bad scientist. His intellectual 

 vision of evolution as a feet, as something happening, 

 something whole, to be apprehended in a unitary way 

 — that is unsurpassed. He seems to see it as vividly 

 as you or I might see a hundred yards race, holding its 

 different incidents and movements all in his mind 

 together to form one picture. But he then goes on 

 to give a symbolic description of what he sees — and 

 then thinks that his symbols will serve in place of 

 analytic explanations. There is an ' urge of life ' ; 

 and it is, as a matter of fact, urging life up the steps 

 of progress. But to say that biological progress is 

 explained by the clan vital is to say that the movement 

 of a train is ' explained ' by an elan locomotif of the 

 engine : it is to fall into the error, so often condemned 



c 



