X INTRODUCTION 



According to the idealistic way of thinking all living 

 things, including human beings, originally came into being 

 in more or less the same form in which we now see them, 

 owing to the effect of supernatural spiritual forces, that is to 

 say as the result of a creative act by a deity, formative origin- 

 ating spirit, life force, entelechy or some such concept. In 

 other words, they arose as the result of the influence of a 

 primary spiritual cause which was, itself, according to the 

 idealists, the essence of life. 



In opposition to this, the materialistically minded scientists 

 and philosophers set out from the premise that life is material 

 in nature like everything else in the world, and that no 

 spiritual force need be invoked to explain its origin. As most 

 of them accepted spontaneous generation as a fully confirmed 

 ' fact ', they had to explain it as the result of the action 

 of natural laws, while denying the intervention of any 

 spiritual force whatever. It seemed to them that the most 

 direct approach to a solution of the problem of the origin 

 of life was to find in nature, or produce in the laboratory, 

 instances of spontaneous generation, and to study the pheno- 

 menon by all the available scientific methods. 



However, very accurate observations and experiments, 

 especially the researches of Louis Pasteur, demonstrated con- 

 clusively the illusory nature of the very ' fact ' of the spon- 

 taneous generation of even the most primitive organisms 

 from inanimate material. It was established with complete 

 certainty that all previous reports of the occurrence of spon- 

 taneous generation had been the fruit of errors of method, 

 incorrect setting up of experiments or superficial interpreta- 

 tion of them. 



This removed the ground from under the feet of those 

 students of nature who saw spontaneous generation as the 

 only conceivable way in which life could have arisen. After 

 Pasteur they lost all possibility of an experimental approach 

 to the solution of this problem and this led them to form 

 very pessimistic conclusions and to assert that the problem 

 of the origin or life was * accursed ' and that it was an 

 insoluble question unworthy of the work of any serious 

 investigator and to study it would be simply a waste of his 

 time. 



