CHAPTER III 



THE SCIENTIFIC LAW 



S I . — Resume and Foreword 



The discussions in my first two chapters have turned 

 upon the nature of the method and material of modern 

 science. The material of science corresponds, we have 

 seen, to all the constructs and concepts of the mind. 

 Certain parts of this material, namely, constructs associ- 

 ated with immediate sense-impressions, we project outwards 

 and speak of as physical facts or phenomena ; others, 

 which are obtained by the mental processes of isolation 

 and co-ordination from stored sense-impressions, we are 

 accustomed to speak of as mental facts or concepts. 

 In the case of both these classes of facts, the scientific 

 method is the sole path by which we can attain to know- 

 ledge. The very word knowledge, indeed, only applies to 

 the product of the scientific method in this field. Other 

 methods, here or elsewhere, may lead to fantasy, as that 

 of the poet or of the metaphysician, to belief or to super- 

 stition, but never to knowledge. As to the scientific 

 method, we saw in our first chapter that it consists in 

 the careful and often laborious classification ^ of facts, in 

 the comparison of their relationships and sequences, and 

 finally in the discovery by aid of the disciplined imagina- 

 tion of a brief statement or formula, which in a few words 

 resumes a wide range of facts. Such a formula, we have 



1 The reader must be careful to recollect that classification is not identical 

 with collection. It denotes the systematic association of kindred facts, the 

 collection, not of all, but of relevant and crucial facts. 



