14 THE GRAMMAR OF SCIENCE 



For we must note that when from a sufficient if partial 

 classification of facts a simple principle has been discovered 

 which describes the relationship and sequences of any 

 group, then this principle or law itself generally leads to 

 the discovery of a still wider range of hitherto unregarded 

 phenomena in the same or associated fields.^ Every great 

 advance of science opens our eyes to facts which we had 

 failed before to observe, and makes new demands on our 

 powers of interpretation. This extension of the material 

 of science into regions where our great-grandfathers could 

 see nothing at all, or where they would have declared 

 human knowledge impossible, is one of the most remark- 

 able features of modern progress. Where they interpreted 

 the motion of the planets of our own system, we discuss 

 the chemical constitution of stars, many of which did not 

 exist for them, for their telescopes could not reach them. 

 Where they discovered the circulation of the blood, we 

 see the physical conflict of living poisons within the blood, 

 whose battles would have been absurdities for them. 

 Where they found void and probably demonstrated to 

 their own satisfaction that there was void, we conceive 

 great systems in rapid motion capable of carrying energy 

 through brick walls as light passes through glass. Great 

 as the advance of scientific knowledge has been, it has 

 not been greater than the growth of the material to be 

 dealt with. The goal of science is clear — it is nothing 

 short of the complete interpretation of the universe. But 

 the goal is an ideal one — it marks the direction in which 

 we move and strive, but never a stage we shall actually 

 reach. The universe grows ever larger as we learn to 

 understand more of our own corner of it. 



^ 6. — Science and Metaphysics 



Now I want to draw the reader's attention to two 

 results which flow from the above considerations, namely : 



1 For example, while in the last two decades our theory of light and mag- 

 netism has advanced by leaps and bounds, we have at the same time discovered 

 wide ranges of novel phenomena, of which we had previously no cognisance. 



