28o THE EVOLUTIONARY CAREER 



inherited (which is denied by many investigators) there is organic 

 evolution. 



But obviously Lamarckian evolution means individual 

 organismal change with tendency. 



ii. Darwinian evolution. Organisms, in themselves, display 

 randomly occurring changes and such randomness is inherent in 

 the organismal make-up. If some of the random changes in 

 activity are inherited by the progenies of the individuals in which 

 they first occur there is evolution. This is because some of the 

 random changes are " selected," which means that organisms and 

 their progenies have changed so that they may become more 

 ubiquitous in distribution, live longer and reproduce more often. 

 Not all random and inheritable changes have such effects and 

 therefore in Darwinian evolution there is individual organismal 

 change with tendency. 



Hi. Evolution by special creation. This means, it would 

 appear, that the novelties, or changes, in organic life-histories are 

 to be regarded as " acts of God." But since the novelties appear 

 to have occurred as sequences that have tendencies the creative 

 acts cannot be regarded as arbitrary, or random ones. It has 

 been said that organic evolution may be thought about as the 

 working-out of a creative thought in the Divine mind. We do 

 not know, of course, what we mean by God in this connection 

 except as an agency that operates in nature and we can only regard 

 the results of that agency as individual organismal change with 

 tendency. On ultimate analysis (so far as we can proceed with it) 

 it is therefore difficult to say in what essential respect the hypo- 

 theses of evolution that we have considered differ from each other. 

 Except in this way — and here we find two ways of thinking 

 about our problem. Formal religions include the idea that the 

 Divine agency may only be modified by supplication, or prayer : 

 thus we contemplate the processes of evolution rather than attempt, 

 by our own efforts, to modify them. On the other hand, science 

 may be regarded not only as the search for truth, that is, the 

 discovery of whatever there is in the external world (whether the 

 discovery be useful or not), but also as the attempts by man to 

 modify the course of events in the external world (whether, or 

 not, such modifications are useful to us). Scientific men believe 

 that they are (however slightly) influencing the evolutionary 

 process by experimental interference and the idea that there is 



