RELATIONS OF LOGIC TO OTHER DISCIPLINES 311 



(5) While logic thus goes back to epistemology for its bases and for 

 the theoretical determination of the interrelation of knowledge and 

 truth, it goes forward in its application to the practical service of the 

 sciences as their methodology. A part of its subject-matter is therefore 

 the actual procedure of the sciences, which it attempts to organize 

 into systematic statements as principles and formulae. This body of 

 rules given implicitly or explicitly in the workings and structure of 

 the special sciences, consisting in classification, analysis, experiment, 

 induction, deduction, nomenclature, etc., logic regards as a concrete 

 deposit of inferential experience. It abstracts these principles from 

 the content and method of the sciences, describes and explains them, 

 erects them into a systematic methodology, and so creates the 

 practical branch of real logic. Formal logic, therefore, according to 

 the foregoing account, would embrace the questions of the internal 

 congruity and self-consistency of thought and the schematic arrange- 

 ment of judgments to insure formally valid conclusions; real logic 

 would embrace the epistemological questions of how knowledge is 

 related to reality, and how it is built up out of experience, on the 

 one hand, and the methodological procedure of science, on the other. 

 The importance of mathematical logic seems to be mainly in the 

 facilitation of logical expression through symbols. It is rather with 

 the machinery of the science than with its content and real problem 

 that the logical algorithm or calculus is concerned. In these con- 

 densed paragraphs sufficient has been said, I think, to show that logic 

 and psychology should be regarded as coordinate disciplines; for their 

 aims and subject-matter differ too widely to subordinate the former 

 under the latter without confusion to both. 



I wish now to add a brief note on the relation of logic to another 

 discipline. 



III. Relation of logic to metaphysics. 



As currently expounded, logic either abuts immediately on the 

 territory of metaphysics at certain points or is entirely absorbed in it 

 as an integral part of the metaphysical subject-matter. I regard the 

 former view as not only the more tenable theoretically, but as 

 practically advantageous for working purposes, and necessary for 

 an intelligible classification of the philosophical disciplines. The 

 business of metaphysics, as I understand it, is with the nature of 

 reality; logic is concerned with the nature of validity, or with the 

 relations of the elements of thought within themselves (self-consist- 

 ency) and with the relations of thought to its object (real truth), but 

 not with the nature of the objective world or reality as such. Further, 

 metaphysics is concerned with the unification of the totality of 

 knowledge in the form of a scientific cosmology; logic is concerned 



