THE BREATH OF LIFE 



forces, but material and chemical forces do not hold 

 the secret of life. This is vitalism as opposed to 

 mechanism, or scientific materialism, which is the 

 doctrine of the all-sufficiency of the physical forces 

 operating in the inorganic world to give rise to all 

 the phenomena of the organic world — a doctrine 

 coming more and more in vogue with the progress of 

 physical science. Without holding to any belief in 

 the supernatural or the teleological, and while ad- 

 hering to the idea that there has been, and can be, 

 no break in the causal sequence in this world, may 

 one still hold to some form of vitalism, and see in 

 life something more than applied physics and chem- 

 istry? 



Is biology to be interpreted in the same physical 

 and chemical terms as geology? Are biophysics and 

 geophysics one and the same? One may freely ad- 

 mit that there cannot be two kinds of physics, nor 

 two kinds of chemistry — not one kind for a rock, 

 and another kind for a tree, or a man. There are 

 not two species of oxygen, nor two of carbon, nor two 

 of hydrogen and nitrogen — one for living and one 

 for dead matter. The water in the human body is 

 precisely the same as the water that flows by in the 

 creek or that comes down when it rains; and the sul- 

 phur and the lime and the iron and the phosphorus 

 and the magnesium are identical, so far as chemical 

 analysis can reveal, in the organic and the inorganic 

 worlds. But are we not compelled to think of a 



72 



