An Introduction to a Biology 



abstraction of the human mind. Our very existence, accord- 

 ing to Bergson, is Time. I need not labour the point that 

 our very existence, our real being, is in essence a flow. 

 Anyone who has devoted himself closely to the study of 

 his fellow men, or of himself, must be aware that man's 

 psychic existence is a flow of moods like the procession of 

 shadow, rain, and sunshine across a landscape on a windy 

 day. 



Now if we hold a mechanistic interpretation of life 

 in other words, if we believe Natural Selection to be the 

 explanation of evolution, we believe that the changes which 

 have taken place in the habits and, in general, the actions 

 or activities of animals and plants have been preceded by 

 structural changes in the organs (I might almost say the 

 parts of the machines) which performed those actions. 

 According to this view, changes in form lead the way ; 

 changes in activity follow in their wake. 



But if you hold a vitalistic interpretation of life, as 

 Lamarck did, and Butler did, and Bergson does, it is just 

 the other way. That which leads the way is changes in 

 activity or attempted action ; that which follows behind 

 (because it is brought about by this action) is changes in 

 the organ which attempted to perform the action. Now 

 we know that the more often an action is performed the 

 more fixed does it become. And if we believe that the 

 shape of an organ becomes gradually fixed over the course 

 of countless generations by the repetition for myriads of 

 times of a particular action by that organ, then we believe 

 that the fixation of that character is due to the repeated 

 performance of an act by the organism which possesses it ; 

 which performance is an integral part of the very life of 

 the species ; which life is the stream made up of the suc- 

 cessive generations, i.e. the time lived by that species. In 

 other words, Time has everything to do with the fixation of 

 a character. The longer the action, which is the function 

 of a given organ, has been performed, the more fixed will 



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