400 DARWINISM AND THE PROBLEMS OF LIFE 



The historian first chooses his theme. This is 

 usually a fact or event that interests him and seems 

 worth study. He then examines the antecedents of 

 this event, and selects those that have a bearing on 

 his subject. Thus a student who is writing a history 

 of the preparatory period of the Reformation will not 

 speak of fashions in dress or the price of food, but will 

 confine himself to the points that have some relation 

 to the Reformation. Again, the evolutionist who is 

 studying the origin of the vertebrates will only 

 describe those of the innumerable changes in the 

 animal world that may be regarded as stages in the 

 formation of the vertebrates. That is not an 

 unscientific procedure — not teleology in the sense we 

 described above. The historian neither forces the 

 chain of causes towards his aim, nor fancies that they 

 sought this end from the first ; he merely studies only 

 those meshes in the network of causes and effects that 

 lie before the phenomenon whose origin he is investi- 

 gating. This way of studying it arranges agencies in 

 a straight line, and makes them seem to be aiming at a 

 certain result. 



The evidence for the evolution of animals differs 

 from that we consult in human history. Most of it 

 is of such a character that we have first to justify our 

 action in regarding it as evidence. This justification 

 is furnished by the laws of science. The law which 

 says that organisms are constantly changing, and that 

 every living thing descends from some other one, gives 

 us the right to regard the remains of the different 



