488 FURTHER EVOLUTION 



above. At first organic materials developed over the course 

 of many hundreds of millions of years. Then they were trans- 

 formed into polymers of high molecular weight which formed 

 individual open systems, and only as a result of the directed 

 evolution of these systems did there arise the first, primitive 

 organisms, the simplest forms of life. 



However, when this happened the origin of living from 

 lifeless material began to take place on a gigantic scale with 

 extraordinary thoroughness, as we can see every day and 

 everywhere at the present time. 



The people who put the question are not, however, usually 

 interested in the origin of living material through the agency 

 of living things (this seems to them very trivial), but in 

 whether living material can now arise on our Earth primarily, 

 directly in a lifeless natural medium. This is yet a third 

 aspect of our question. 



Many people give a purely theoretical answer to this, being 

 convinced that when once any form of the motion of matter 

 has arisen, then it must still go on arising now. This assump- 

 tion, however, is only valid for the Universe as a whole and 

 not for some particular limited system such as the Earth. 

 In this case such a presentation of the problem can lead to 

 a completely unwarrantable inference. 



To clarify this I shall give the following simple example. 

 The origin of man was undoubtedly one of the most import- 

 ant stages in the development of matter. This stage is wholly 

 comparable with the origin of life. If the origin of life 

 involved the appearance of a new, biological form of the 

 motion of matter, so man is the culmination of this biological 

 development and his origin involved the transition to a still 

 higher, social form of the motion of matter. We do not doubt 

 that man arose on the Earth during the process of the develop- 

 ment of life but there can hardly be anyone who would main- 

 tain that he arises nowadays on our planet without being 

 born from another like himself, but in some other way. 



Let us imagine some sterile tank of water, free from living 

 things, with various organic substances dissolved in the water. 

 If it were left to itself, the processes of transformation of sub- 

 stances which we described above would come about slowly 

 in it. Finally, during many millions of years, this would lead 



