152 THE NEW PHYSIOLOGY. 



of reality is presented. In the world of psychology 

 still more of reality comes before us. The real world 

 is not merely a physical or biological world, but also 

 a known world. In identifying it as a known world we 

 are making use of an additional category or working 

 hypothesis. What makes this necessary is simply the 

 nature of the empirical facts. A world which is not a 

 known world means as little to us as a world in which 

 the equation PV=RT holds good absolutely, or a world 

 of atoms indifferent to one another. Such worlds are only 

 ideal figments of our imagination, though the figments 

 are very useful for certain limited purposes. In judging 

 of the nature of reality we have no right to exclude the 

 facts which emerge in either biological or psychological 

 observation. It would be just as reasonable to exclude 

 from physics or chemistry all the facts relating to 

 ionisation. Conscious activity is a part of our objective 

 universe, and must be taken account of in our judgments 

 of reality. 



Consciousness has been looked upon as a mere accom- 

 paniment of physical and chemical changes in nerve- 

 cells. As has been already pointed out, the active 

 changes within the living body cannot be interpreted 

 as mere physical and chemical changes. 



An alternative view is that conscious activity is a 

 subjective accompaniment of what we interpret as vital 

 activity. To me it seems clear that this view is not 

 possible. Vital activity is " blind." This means that 

 the organic unity which we can always identify in vital 

 or biological activity is immediate in character. An 

 unconscious organism adapts itself to new conditions, 

 but only through a process which appears to be essen- 



