NATURE OF EXACT SCIENCE 251 



deity — which will not be engulfed by the advance of 

 exact science; and our apprehension is not directed 

 against the particular entities of physics but against all 

 entities of the category to which exact science can apply. 

 For exact science invokes, or has seemed to invoke, a 

 type of law inevitable and soulless against which the 

 human spirit rebels. If science finally declares that man 

 is no more than a fortuitous concourse of atoms, the 

 blow will not be softened by the explanation that the 

 atoms in question are the Mendelian unit characters 

 and not the material atoms of the chemist. 



Let us then examine the kind of knowledge which is 

 handled by exact science. If we search the examination 

 papers in physics and natural philosophy for the more 

 intelligible questions we may come across one beginning 

 something like this: "An elephant slides down a 

 grassy hillside. . . ." The experienced candidate knows 

 that he need not pay much attention to this; it is only 

 put in to give an impression of realism. He reads on: 

 "The mass of the elephant is two tons." Now we are 

 getting down to business; the elephant fades out of the 

 problem and a mass of two tons takes its place. What 

 exactly is this two tons, the real subject-matter of the 

 problem? It refers to some property or condition which 

 we vaguely describe as "ponderosity" occurring in a 

 particular region of the external world. But we shall not 

 get much further that way; the nature of the external 

 world is inscrutable, and we shall only plunge into a 

 quagmire of indescribables. Never mind what two tons 

 refers to; what is it? How has it actually entered in so 

 definite a way into our experience? Two tons is the 

 reading of the pointer when the elephant was placed 

 on a weighing-machine. Let us pass on. "The slope 

 of the hill is 6o°." Now the hillside fades out of the 



