INTRODUCTION XI 



This led to a serious crisis in the ideas of many scientists 

 of our century concerning the problem with which we are 

 dealing. Some of these scientists tried to get out of the 

 question by suggesting that life never arose on Earth but that 

 the first living things were brought here from somewhere 

 else such as the surface of one of the nearer or more distant 

 planets. Others got round the question of the origin of life 

 by adopting openly idealistic positions and declaring that 

 the problem belonged, not to the province of science but to 

 that of faith. 



It was, of course, not the nature of the problem which led 

 to this crisis but the fact that scientists were using faulty 

 methods in their approach to it. 



It was the outstanding service of Charles Darwin to biology 

 that he broke with the earlier metaphysical methods for attack- 

 ing the problem of the origin of the existing forms of animals 

 and plants. He showed, beyond question, that highly organised 

 living creatures can appear on the Earth only as the result 

 of prolonged development, that is, evolution of higher forms 

 from lower ones. In the absence of such evolution it was 

 impossible to maintain that human beings or other highly 

 developed organisms had arisen by natural means without 

 the intervention of any spiritual or supernatural agency. 



However, even after Darwin's work, scientists approached 

 the problem of the origin of the very simplest living things, 

 which were the first ancestors of every living thing on Earth, 

 in the same metaphysical way which had prevailed in regard 

 to more highly organised organisms before Darwin's time. 

 We have, however, already seen that, even after the work of 

 Darwin, people tried to explain the origin of life by separ- 

 ating it from the general development of matter. They 

 regarded it as a sudden act of spontaneous -generation of 

 organisms which, though themselves primitive, were still 

 endowed with all the complicated attributes of life. This 

 approach to a solution of the question was, however, found 

 to be radically inconsistent with the results of experiment 

 and observation and could therefore lead to nothing but 

 bitter disappointment. 



A completely different prospect opens out before us if we 

 try to approach a solution of the problem dialectically rather 



