OF KNOWLEDGE. 405 



of their gradual development identified with the lead- 

 ing representatives of the various mathematical, physical, 

 and natural sciences. 



If we now look at the whole of this change, in the 

 midst of which we are living, from a different point of 

 view, we are led back to the observation with which I 

 opened the Introduction to this, the second, part of our 

 historical survey. We may say that this change consists 

 in finding and fixing new meanings to the existing words 

 of our current language ; occasionally also in coining 

 new terms wherewith to fix certain ideas and meanings 

 which are unconsciously striving after clearness and 

 adequate expression. Prominent examples of this kind 

 are afforded by the words force, cause, and development. 

 It is a clarifying process. But every definition has not 

 only the advantage of producing clearness and exacti- 

 tude ; it has also the disadvantage of narrowing the field 

 of vision, of limiting the view, leaving out much that 

 lies outside, but which, though less defined, is not 

 necessarily less real and important. If the scientific 

 definition of the word force tends in the direction of 

 making the word superfluous in mechanical science, it 

 does not therefore destroy the deeper meaning of force 

 as the cause or origin of motion which we continually 

 experience individually in our voluntary efforts. If the 

 terms cause and effect are discarded for the more easily 

 defined terms antecedent and subsequent in time, we do 

 not hereby get rid of looking for the sufficient reason 

 and ultimate ground of this sequence and for the final 

 end and purpose. If we are told that the object of 

 science is to describe phenomena as simply and as com- 



