DIFFERENT KINDS OF EVOLUTION 5 



bones of mammals, vet in neither case does a knowl- 

 edge of the order in which these things arose explain 

 them. If we appeal to the psychologist he will prob- 

 ably tell us that human inventions are either the 

 result of hapj)y accidents, that have led to an un- 

 foreseen, but discovered use; or else the use of the 

 invention was foreseen. It is to the latter process 

 more especially that the idea of pur pose is applied. 

 When we come to review the four great lines of 

 evolutionary thought we shall see that this human 

 idea of purpose recurs in many forms, suggesting 

 that man has often tried to explain how organic evo- 

 lution has taken place by an appeal to the method 

 which he believes he makes use of himself in the 

 inorganic world. 



What, I repeat, has the evolution of the stars in 

 common with the evolution of the horse, and what 

 have these in common with the evolution of human in- 

 ventions? Clearly no more than that from a simple 

 beginning through a series of changes something 

 more complex, or at least different, has come into 

 being. To lump all these kinds of changes into one 

 and call them evolution is only to assert that you be- 

 lieve in consecutive series of events (which is history) 

 causally connected (which is science). It is the aim 

 of science to find out ^/^^cZ/zca//?/ what kinds of causes 

 were at work when the stars evolved in the sky, when 

 the horse evolved on the earth, and the steam engine 

 was evolved from the mind of man. 



