10 UNIVERSITY OF MISSOURI BULLETIN 



it is certainly not applicable at all. The sciences are one, for 

 example, in the sense that they all deal with different aspects 

 or parts of one universe. But this is a pretty barren kind of 

 unity; it remains always the same and always equally obvious. 

 The sciences do not in this sense become more nearly unified 

 through the progress of inquiry ; for there needs no inquiry 

 to discover this empty truism. Again, in a very broad sense 

 the method of all the sciences is one ; they all consist in the 

 use of a certain limited number of intellectual processes for 

 the purpose of arriving at generalizations or 'laws' relating to 

 various larger or smaller classes of facts. But this likewise 

 is a sort of unity too evident and too constant to be worth 

 dwelling upon. The unity — or rather the unification, the 

 progress toward unity — about which it is significant to inquire 

 is a thing not obvious at first glance, a unity which does not 

 follow merely from the definition of the abstract term 'science' : 

 one which, rather, reduces, overcomes, harmonizes what ap- 

 pear to be actual and essential differences and discontinuities 

 between the methods or the laws of one science and the 

 methods or laws of another. Thus, in order that the idea of 

 the unity of science may mean something definite and concrete 

 — and in order that the question concerning the present degree 

 of approach to that unity may be intelligently discussed — it is 

 necessary first of all to notice what the more fundamental 

 and significant differences between the sciences are. 



Now, though, in the arrangement of the topics of the 

 lectures to follow, we have adopted the conventional divisions, 

 I suppose every one understands that the determination of 

 what bodies of knowledge should be set apart as distinct 

 sciences and given a proper name has always been a good 

 deal of an historical accident. The traditional classification 

 has no great logical value. Certain superficially obvious pecul- 

 iarities of certain classes of objects caused them to be dis- 

 criminated as the subjects of a specialized study; or certain 

 considerations of mere convenience caused the segregation of 

 certain fields of inquiry. Stars, for example, seem very dif- 



