566 PHILOSOPHICAL THOUGHT. 



words can be as little dispensed with in language and 

 literature as the terms matter and force. In using 

 them we appeal in the one case as well as in the other 

 to the meaning which every thinking person involun- 

 tarily connects with them, and which is based upon 

 definite subjective experience. Now the two classes of 

 experience, of which the terms matter and force on the 

 one side, idea and spirit on the other, are typical, differ 

 widely ; they represent the inner and the outer worlds 

 of experience. It is the desire of philosophy to bring 

 them together in some conception, theory, or creed in 

 which their mutual relation and respective importance 

 are recognised. In this endeavour it is, prima facie, 

 just as legitimate to start with the one class as with 

 the other. It depends upon the reality and importance 

 which the thinker attaches respectively to the two sides 

 of experience which way he will choose. Practice, how- 

 ever, has shown that the terms referring to the outer 

 world, such as matter and force, referring as they do 

 to things located in space, are capable of a mathematical 

 definition, and in consequence of a systematic elabora- 

 tion, to which the other class of terms do not lend 

 themselves. From this it of course does not follow 

 that the latter do not refer quite as much as the former 

 to real experiences, as we have slowly learned that ever 

 so clear a definition is not identical with, and does not 

 necessarily imply, certainty. 



if*. One of the principal causes of the widespread mis- 



inexactness 



uVterin 0pu ' understanding which existed, and still exists, about the 

 creed of materialism is to be found in the use of the 

 word Force. Not till the term was mathematically 



