70 THE FOUNDATIONS OF SCIENCE 



of preparing the more complex organic substances 

 which have hitherto defied the resources of our chemi- 

 cal laboratories. It does not depend on our failure 

 to explain the more recondite physical and electrical 

 phenomena of living cells, nor on our failure to manu- 

 facture life from inorganic matter. It is never safe 

 to build conclusions on the mere gaps in knowledge. 

 But it is required because we have to account for 

 phenomena which are different in kind to those 

 others to account for growth, reproduction, for 

 the unity of a complex organism, for the transcen- 

 dent fact of consciousness, in short, for the problem 

 of life itself. 



