THE STABILITY OF TRUTH. 343 



plausible ? Has it logical continuity ? Is it satisfying 

 to the human heart?" And in this connection the fig- 

 urative word "heart " is best left undefined. In other 

 words, the sources and tests of philosophy are alike 

 subjective, intellectual or emotional. If we take from 

 philosophy the "heart " element, the personal equation, 

 it becomes logic or mathematics. Mathematics is meta- 

 physics working through methods of precision. It is 

 a most valuable instrument for the study of the rela- 

 tions and ramifications of knowledge, but it can give no 

 addition to knowledge itself. Dr. William James defines 

 metaphysics as " the persistent attempt to think clearly." 

 This definition is good so far as it goes, but to think 

 clearly is a function of science also. Metaphysics is 

 rather the " attempt to think clearly" in fields where 

 exact data are unattained or unattainable. 



For example, the claim is made in the name of evo- 

 lutionary philosophy that all matter is one in essence, 



n , therefore all the chemical elements. 



Frotyl. ' 



some seventy in number, must be the 

 same in substance. In this case all must be derived 

 from the same primitive stuff, and the hypothetical basis 

 of all ponderable matter has been called protyl. As a 

 working theory this is most ingenious. But is it science ? 

 Is it worthy of belief ? Certainly science knows nothing 

 as yet of the identity of these elements. In a general 

 way science is finding out that the processes of Nature 

 are more complex than man had supposed, while the 

 elements on which these processes rest, matter and 

 force, are more simple. How far can this generaliza- 

 tion go ? To every test human experience has devised 

 each chemical element remains the same, its atoms un- 

 changeable as well as indestructible. Therefore to 

 speak of them as forms of one substance is to go beyond 

 knowledge. Science does not teach this. But to phi- 



