SENSORY AND RATIONAL DISCRIMINATION 135 



field of measurement. Hence it is that the instru 

 ments valued in experimental psychology render no 

 aid in interpreting the phenomena of consciousness. 



The facts of external observation are set on one side, 

 the facts of rational exercise are set on the other. This 

 much is implied in the correlated claims of science, 

 and of philosophy. As the argument for continuity of 

 lifejsstrong along ^he whole line of research con- ^ 

 cerned wit JTorganTsm ; so is the argument for breach of 

 strong by failure of physiological science to 

 phenomena of rational life. Experimental 

 psychology has become demonstrator of the contrast. 

 Thus, fresh force is given to the words of Professor 

 Burdon Sanderson, already quoted : There is little 

 ground for the apprehension which exists in the 

 minds of some, that the habit of scrutinising the 

 mechanism of life tends to make men regard what 

 can be so learned as the only kind of knowledge. 

 What we have to guard against is the mixing of two 

 methods. The law of induction is the same, but it is 

 applied in two spheres. The laws of observation are 

 identical, whether observation is directed upon the 

 external or upon the internal. But there are two 

 modes of observation, the one by eye and hand, and 

 auxiliary senses; the other by direct consciousness 

 belonging to a rational life. Inclusion of the facts of 

 rational activity with functions of organism cannot be 

 maintained. Rational discrimination stands distinct 

 from sensory discrimination. 



Acting according to its own laws, and exercising 

 gift oT self-criticism, rational power concerns itself 

 with the manifold forms of existence. It distin 

 guishes at once the elements of conscious ex- 



