THE MECHANISTIC CONCEPTION 15 



when he said : "The essence of life is not protoplasm, 

 but purpose." Yet we see about us animals and 

 plants which are continually changing dead into 

 living substance. That these transformations are 

 accomplished by the aid of perfectly definite physical 

 and chemical mechanisms is a reasonable belief, and 

 there is no doubt that much is to be learned by the 

 further investigation and imitation of these natural 

 processes. But we must not forget the possibility 

 that life has never had a beginning at all, or that it 

 is as old as matter itself. To so good a mind as that 

 of Helmholtz this seemed a not unreasonable view. 

 And Helmholtz asked " whether seeds have not been 

 carried from one planet to another and been developed 

 everywhere where they have fallen on a fertile 

 soil." This hypothesis of panspermia has latterly 

 been ingeniously extended by Arrhenius and deserves 

 serious attention. 



Thus we see that the origin and nature of living 

 protoplasm is veiled in the utmost obscurity. For 

 many investigators this obscurity seems so serious 

 as to discourage attempts to create living from dead 

 material; others, however, feel that it is essential 

 to continue to make trials in this direction, if only in 

 the hope of incidentally gaining a deeper insight 

 into living processes. What here especially con- 

 cerns us is that even if the attempts to make liv- 

 ing matter should ultimately fail, this failure would 

 not necessarily compel us to abandon a mechanistic 

 hypothesis of living material. In other words, the 



