CONTRIBUTION TO THE THEORY OF SCIENCE 225 



tions only those interest us which are repeated. This arbitrary though 

 fit selection creates the impression that these are the only recurring 

 combinations, or that, in other words, the law of casuality or of type 

 rules unqualifiedly. How universal or how limited is the application 

 of these laws is therefore rather a question of our skill in selecting the 

 constant combinations from among all those occurring than a question 

 of objective natural phenomena. 



Thus we observe the development and practise of all sciences pro- 

 gressing in this manner by the discovery, on the one hand, of ever more 

 numerous individual constant combinations, and, on the other, of more 

 and more universal laws by means of which components are brought 

 into relation with one another, which formerly no one had attempted to 

 bring together. Thus sciences grow in that they become complex and 

 at the same time unified. 



If now we consider the development and course of the various 

 sciences from this point of view we shall attain a rational classification 

 of all science by an inquiry into the extent and complexity of the com- 

 binations or complexes which they treat. Both characteristics are in a 

 sense antagonistic. The simpler a complex is, that is, the fewer the 

 components united in it, the more frequently will it occur; and vice 

 versa. It will therefore be possible to classify all the sciences in this 

 fashion by beginning with the minimum of complexity and the maxi- 

 mum of extent and ending with the maximum of complexity and the 

 minimum of extent. The first science will include the most general 

 and therefore the poorest and most meager concepts ; the last the most 

 specialized and therefore the richest. 



What then are these limiting concepts ? The most universal is the 

 thing, any fraction of experience arbitrarily selected from the stream 

 of our experiences and capable of repetition. The most specialized and 

 the richest is the concept of human society. Between the study of 

 things and the study of human society all the remaining sciences may 

 be interpolated in an orderly series. The attempt to follow out this 

 scheme leads to the following table: 



1. Science of manifoldness or assemblages, Logic. 



2. Science of numbers or arithmetic, "1 



3. Science of time, r Mathematics. 



4. Science of space or geometry, J 



h 



5. Mechanics, 



6. Physics, 5-Energetics. 



7. Chemistry, J 



8. Physiology, "] 



9. Psychology, j-Biology. 

 10. Sociology, J 



This table contains an arbitrary element inasmuch as the steps 

 assumed in it may be multiplied. Thus mechanics and physics might 

 vol. Lxvm, — 15. 



