28 PHYSICS 



opening passages of his recent Treatise on Physics, Chwolson 1 has 

 employed. 



"For every one there exist two worlds, an inner and an outer, and 

 our senses are the medium of communication between the two. The 

 outer world has the property of acting upon our senses, to bring about 

 certain changes, or, as we say, to exert certain stimuli. 



"The inner world, for any individual, consists of all those phe- 

 nomena which are absolutely inaccessible (so far as direct observa- 

 tion goes) to other individuals. The stimulus from the outer world 

 produces in our inner world a subjective perception which is de- 

 pendent upon our consciousness. The subjective perception is made 

 objective, viz., is assigned time and place in the outer world and given 

 a name. The investigation of the processes by which this objectiv- 

 ication is performed is a function of philosophy." 



Some such confession of faith is good for the man of science, lest 

 he forget; but once it is made he is free to turn his face to the light 

 once more, thankful that the investigation of objectivication is, indeed, 

 a function of philosophy, and that the only speculations in which he, 

 as a physicist, is entitled to engage are those which are amenable at 

 every step to mathematics and to the equally definite axioms and 

 laws of mechanics. 



1 Chwolson, Physik, vol. i, Introduction. 



