THE ORIGIN OF LIFE 87 



So far as direct observation goes, it teaches us that every 

 living organism which originates to-day presupposes another 

 homogeneous organism from which it originates. The old doc- 

 trine of the great English physiologist Harvey, Omne vivum 

 ex ovo, or more correctly, Omne vivum e vivo, is true to-day if 

 we are content to consult our own experience gained from obser- 

 vation. It would, of course, be most convenient to assume that 

 life on earth has existed in its present variety since eternity 

 in other words, that this wealth of animal and plant life was 

 called forth by a spontaneous divine act of creation, and had main- 

 tained itself by reproduction. Indeed, as long as man clung to 

 the traditions of the Church this theory remained victorious. 

 Even to-day we find in certain orthodox circles the attempt to 

 defend the biblical creation myths as scientific facts. Science, 

 however, has long since passed over these endeavours ' and pro- 

 ceeded to the first item of the business of the day.' 



To-day we can admit no justification for tendencies of this 

 kind without doing violence to our reason. The results of 

 researches made in geology, palaeontology, comparative anatomy 

 and biology impel us in an equally convincing manner to assume 

 for the world of organisms a gradual law-governed development 

 from the simplest forms to more and more complex and higher 

 organisms. 



The number of investigators who have tried the edge of their 

 speculative powers since ancient times on this most difficult and 

 most interesting problem of all is legion. We have already 

 seen that Anaximander and Empedocles attempted to give a 

 natural explanation of the origin of organisms, but the state 

 of contemporary knowledge being what it was, these theories 

 did not exceed the value of an ingenious fancy sketch. We are 

 even inclined to regard with derision the conception of Aristotle, 

 according to which even the higher organized animals, such as 

 eels and frogs, were generated spontaneously out of mud, or 

 insects out of putrifying wood. But we have very little cause 

 for feeling superior to him, for it is not so long since similar 

 views were discussed seriously even in scientific circles. Every- 

 one knows that in mediaeval times, when alchemy was flourish- 

 ing, serious men were endeavouring to generate in the retort of 

 the chemical laboratory a little mannikin, the Homunculus. 



