40 THE NEW PHYSIOLOGY. 



sufficient, it makes little or no difference to the consump- 

 tion in the long run if that consumption is measured, in 

 terms of energy value ; and whether light is super- 

 abundant or just sufficient it makes, within enormous 

 limits, equally little difference to our sense of the 

 brightness and visibility of things. It is the same with 

 oxygen. On the summit of Pike's Peak, with the partial 

 pressure of oxygen in the lungs only half the normal, 

 there was not the slightest diminution of the oxygen 

 consumption, just as there is not the slightest increase 

 when pure oxygen is breathed and the partial pressure 

 in the lungs is six times the normal. The organic de- 

 termination which dominates the internal environment 

 of the body dominates also the causal influence on the 

 body of the external environment. Hence we cannot 

 possibly look to the constancy of physical and chemical 

 influence of the external environment for an explanation 

 of the constancy of the internal environment and activi- 

 ties of the body. We should again be playing an aimless 

 game of battledore and shuttlecock. If we seek for a 

 " causal " explanation in the past history of the organism 

 itself, we are no better off. 



The end of the argument is in sight. The phenomena 

 represented by a living organism cannot possibly be 

 grasped and interpreted one by one, in the manner in 

 which we grasp and interpret what present themselves 

 to us as physical or chemical phenomena occurring in 

 space and time. We must grasp them as a whole, 

 simply because, whether we will or not, they present 

 themselves to us as an organically determined whole. 

 If we take them one by one as events in space and time, 

 and let slip our mental grasp of the whole, we find, as I 



