268 THE KIDDLE OF THE UNIVERSE. 



creator seemed to man to be of human shape, to think 

 with his brain, see with his eyes, and fashion with 

 his hands, it was possible to form a definite picture 

 of this " divine engineer " and his artistic work in the 

 great workshop of creation. This was not so easy 

 when the idea of God became refined, and man saw 

 in his " invisible God " a creator without organs — a 

 gaseous being. Still more unintelligible did these 

 anthropomorphic ideas become when physiology substi- 

 tuted for the conscious, divine architect an uncon- 

 scious, creative " vital force " — a mysterious, 

 purposive, natural force, which differed from the 

 familiar forces of physics and chemistry, and only 

 took these in part, during life, into its service. This 

 vitalism prevailed until about the middle of the 

 nineteenth century. Johannes Miiller, the great 

 Berlin physiologist, was the first to menace it with 

 a destructive dose of facts. It is true that the 

 distinguished biologist had himself (like all others 

 in the first half of the century) been educated in a 

 belief in this vital force, and deemed it indispensable 

 for an elucidation of the ultimate sources of life ; 

 nevertheless, in his classical and still unrivalled 

 Manual of Physiology (1833) he gave a demonstra- 

 tive proof that there is really nothing to be said for 

 this vital force. Miiller himself, in a long series of 

 remarkable observations and experiments, showed 

 that most of the vital processes in the human 

 organism (and in the other animals) take place 

 according to physical and chemical laws, and that 

 many of them are capable of mathematical determina- 

 tion. That was no less true of the animal functions of 

 the muscles and nerves, and of both the higher and the 

 lower sense-organs, than of the vegetal functions of 



