144 THE LIMITATIONS OF SCIENCE 



centuries ago. This dualism, as it may be called, 

 is not confined to science; it is but one phase of that 

 larger dualism of philosophy and ethics which has 

 come down to us from the Greek thinkers ; the claims 

 of two opposing schools of thought are always present 

 to show us that, if the mind can develop a system from 

 one set of postulates, the same results can be obtained 

 from their contraries. 



If then our conception of the nature of things is 

 but a matter of personal conviction, what value is 

 there in the opinion of Professor Lorentz, which I 

 have already quoted, if we wish to obtain an in- 

 sight into the mysteries and operations of nature, we 

 must make hypotheses? If such hypotheses are not 

 capable of proof then they must rest on what Boling- 

 broke so aptly calls our inward sentiment of knowl- 

 edge. The experimentalist who described phenomena 

 from his inward sentiment of what they should be 

 rather than from observations of what they are, would 

 be classed as a nuisance. Such a one not only does not 

 advance our knowledge but he actually retards it, since 

 his work must be repeated before the truth can be 

 known. So, too, the theorist, who relies on his per- 

 sonal conviction and not on facts and laws, builds a 

 structure which is not only temporary and false but 

 must be torn down. If we relegate to metaphysics so 

 large a part of what is commonly called physics, what 

 is left to the science of physics? The answer probably 



