i BIOLOGY, PHYSICS AND CHEMISTRY 29 



progress, on which each visible organism rides during 

 the short interval of time given it to live. 



Now, the more we fix our attention on this con 

 tinuity of life, the more we see that organic evolution 

 resembles the evolution of a consciousness, in which 

 the past presses against the present and causes the 

 f* upspringing of a new form of consciousness, incom- 

 ( mensurable with its antecedents. That the appearance 

 |of a vegetable or animal species is due to specific causes, 

 nobody will gainsay. But this can only mean that if, 

 after the fact, we could know these causes in detail, we 

 could explain by them the form that has been pro 

 duced ; foreseeing the form is out of the question. 1 It 

 may perhaps be said that the form could be foreseen if 

 we could know, in all their details, the conditions under 

 which it will be produced. But these conditions are 

 built up into it and are part and parcel of its being ; 

 they are peculiar to that phase of its history in which 

 life finds itself at the moment of producing the form : 

 how could we know beforehand a situation that is 

 unique of its kind, that has never yet occurred and 

 will never occur again ? Of the future, only that is 

 foreseen which is like the past or can be made up 

 again with elements like those of the past. Such is 

 the case with astronomical, physical and chemical facts, 

 with all facts which form part of a system in which 

 elements supposed to be unchanging are merely put 

 together, in which the only changes are changes of 

 position, in which there is no theoretical absurdity 

 in imagining that things are restored to their place ; 

 in which, consequently, the same total phenomenon, 



1 The irreversibility of the series of living beings has been well set forth 

 by Baldwin (Development and Evolution, New York, 1902 ; in particular 

 p. 327). 



