THE PHYSICAL AND THE MENTAL SCIENCES 109 



the material with which these four different groups of sciences are 

 working. 



Let us start again from the consideration of our original logical 

 purpose. We feel ourselves bound and limited in our will by physical 

 things, by psychical contents, by the demands of other subjects, and 

 by norms. The purpose of all our knowledge is to develop completely 

 all that is involved in this bondage. We want to develop in an over- 

 individual way all the obligations for our submission which are 

 necessarily included in the given objects and the given demands of 

 subjects. We start of course everywhere and in every direction from 

 the actual experience, but we expand the experience by seeking those 

 objects and those demands to which, as necessarily following from the 

 immediately given experience, we must also submit. And in thus 

 developing the whole system of submissions, the interpretation of 

 the experience itself becomes transformed: the physicist may per- 

 haps substitute imperceptible atoms for the physical object and the 

 psychologist may substitute sensations for the real idea, and the 

 historian may substitute combinations of influences for the real per- 

 sonality, and the student of norms may substitute combinations of 

 conflicting demands for the one complete duty; yet in every case the 

 substitution is logically necessary and furnishes us what we call truth 

 inasmuch as it is needed to develop the concrete system of our sub- 

 missions and thus to express our confidence in the order-lines of real- 

 ity. And each of these substitutions and supplementations becomes, 

 as material of knowledge, itself a part of the world of experience. 



3. The Physical and the Mental Sciences 



The physicist, we said, speaks of the world of objects in so far as 

 they belong to every possible subject, and are material for a merely 

 passive spectator. Of course the pure experience does not offer us any- 

 thing of that kind. We insisted that the objects of our real life are 

 objects of our will and of our attitudes, and are at the same time un- 

 differentiatecl into the physical things outside of us and the psychical 

 ideas in us. To reach the abstraction of the physicist, we have thus to 

 cut loose the objects from our will and to separate the over-individual 

 elements from the individual elements. Both transformations are 

 clearly demanded by our logical aims. As to the cutting loose from our 

 will, it means considering the object as if it existed for itself, as if it 

 were a mere passively given material and not a material of our per- 

 sonal interests. But just that is needed. We want to find out how 

 far we have to submit ourselves to the object. If we want to live our 

 life, we must adjust our attitudes to things, and, as we know our will, 

 we must seek to understand the other factor in the complex experi- 

 ence, the object of our will, and we must find out what it involves in 



