116 INTRODUCTION TO SCIENCE 



intellectual house in order a process that tends 

 to clear thinking, but to have a vividly real 

 scheme or map of knowledge is to have a sort of 

 Philosopher's Stone. It adds to the value of 

 our knowledge by always suggesting inter-rela- 

 tions and by serving as a test of completeness 

 and consistency. We all need to be constantly 

 reminded of Plato's demand that the true lover 

 of science shall be interested in the whole of his 

 subject. 



(6) The second great interest of the classifica- 

 tion of the sciences is that it raises the largest 

 and deepest questions. Willy-nilly it expresses 

 a Philosophy. Its boundary-lines express our 

 conclusions as to the autonomy or the depen- 

 dence of Biology and of Psychology, our decisions 

 on the difficult questions of Vitalism and Materi- 

 alism. It is not a matter of indifference whether 

 Sociology should be reckoned as a general science 

 (Comte) or as a branch of Biology (Pearson). It is 

 not by a misprint that we have placed Metaphys- 

 ics beside Mathematics as an Abstract Science. 



As we think over the conflicting classifications 

 of the sciences, we see that a frequent cause of 

 confusion has been the attempt to map out 

 territories as preserves of particular sciences. 

 This implies a wrong idea of the constitution of a 

 science, which is defined not by its subject-matter, 

 but by the categories under which it thinks of 



