374 THE CONCEPT OF EVOLUTION 



spite of transformation of species here and extinction there 

 and blind alleys somewhere else. But there is also a con- 

 tinuity in the external staging, in the extra-organismal sys- 

 tematisations, in what we have called the web of life. This 

 is of extraordinary importance in the case of mankind ; 

 naturalists have not allowed enough for it in the case of 

 animal and plant organisms. 



But we must not exaggerate the idea of continuity. Both 

 as regards the organism and its environment of inter-relations 

 we have to recognise that with all the continuity there is 

 continual change. Birds are continuous with reptiles, but 

 not continuations of them, and at the time of their evolution 

 there was a correlated change in the genesis of the earth 

 which opened to birds a new world indeed. 



While birds are very different from reptiles, indubitable 

 new ideas, it is possible to imagine how a fore-limb could 

 become a wing and a scale a feather, and that sort of dis- 

 continuity is familiar to all students of evolution. On the 

 other hand, it is certain, from centuries of failures, that 

 by no jugglery of words can we account for thinking in 

 terms of matter and motion. Therefore the alternatives 

 (1) to regard the scientific belief in evolution as in part 

 at least an illusion, since what comes later, e.g., thinking, 

 is distinct in kind from what comes earlier; or (2) to sup- 

 pose that the lowest animals are potentially psychical; with, 

 as Sir Francis Darwin puts it (Presidential Address, British 

 Association, 1908), "faint copy of all we know as con- 

 sciousness in ourselves ". The first position is not easy, for 

 the evolutionary explanation is practically proved along ana- 

 tomical and physiological lines; the second position is not 

 easy, for the 'faint copy' becomes faint indeed when we 

 pass to the simplest organisms. 



