The Domain of Physical Science 197 



no one seems to know what the supposed qualification is, nor is it 

 explained in what way the prestige of the external world would be 

 enhanced if it passed the test. It is sufficient that it is the world 

 which confronts our common experience and that therefore we 

 are interested in knowing all we can about it. Scientific theories 

 of it are continually changing, and no one would maintain that the 

 present conception is undiluted ultimate truth ; we can, if we like, 

 take comfort in the reflection that, true or not, it " economises 

 thought." But it would be difficult to justify .the vehemence of 

 the scientific attack on superstition if the sole objection were that 

 it is wasteful of thought. We are roused because we believe that 

 the victims of superstition are embodying in the external world — 

 the common element of experience — conceptions which have no 

 right to be there, and that our conception though not free from 

 error contains more of the truth than theirs. 



We have now discussed to some extent the method employed by 

 physics in reaching its conception of the external world ; we have 

 seen that this world has a claim on our attention not on account of 

 some metaphysical function of " existing," but because it is the 

 world confronting us ; and we have seen why the commonplace 

 view of the world is almost unrecognisable in the scientific view. 

 We have hinted that the scientific view has certain limitations 

 (beyond the ordinary limitations of human fallibility) ; it lays 

 undue stress on the microscopic point of view, and it does not 

 attempt to include a point of view other than that of an intelligence 

 like our own which has presumably developed in rather specialised 

 directions through the operation of natural selection. Those 

 limitations are justified when the scientific conception is used for 

 the purposes of science, but must be borne in mind when the con- 

 ception is studied from the point of view of philosophy or religion. 

 It is now time to consider what is the general nature of the world 

 of physics reached by these methods. 



2. The Scientific Conception of the Universe 



A distinguishing characteristic of physics is that it is an " exact 

 science " and the phrase domain of physics is often used synony- 

 mously with domain of exact science. The vision that with the 

 advance of knowledge it may be found that physical laws are 

 sufficient to explain completely the phenomena of life and heredity 



