14 UNIVERSITY OF MISSOURI BULLETIN 



we may still further restrict our consideration chiefly to the 

 physical sciences. What constitutes the 'oneness' of any one 

 of these, in so far as its possession of a single and separate 

 name is not merely an arbitrary historical accident? And 

 what are the seemingly significant differences between these 

 sciences which a real unification would overcome? We speak 

 of any special science, in the familiar phrase of Herbert 

 Spencer, as "partially unified knowledge" ; upon what does 

 its unified character depend and why is the unification to be 

 regarded as only partial? 



A separate science, as we have seen, usually begins 

 through the grouping together of a number of objects or 

 phenomena which present sufficiently striking common pe- 

 culiarities to lead men's minds to classify them together. 

 Knowledge of these casually grouped objects or phenomena 

 becomes unified — becomes, indeed, a true science — only in so 

 far as, within the limits of the group, uniformities of coexist- 

 ence or succession are discovered which can be stated in gen- 

 eralized formulas or "laws". To unify, then, in any signifi- 

 cant sense, is to bring diverse and seemingly uncoordinated 

 particular facts under a relatively small number of general 

 laws ; and unification progresses in proportion as the laws be- 

 come fewer and the number of facts to which they apply 

 becomes correspondingly larger. It may, at the same time, 

 turn out that other classes of objects or types of phenomena, 

 not originally included in the given science, "obey" the same 

 laws ; and thus the boundaries of the science are at once ex- 

 tended and made more definite and less haphazard. All this, 

 of course, is sufficiently familiar and commonplace, and yet 

 it is easy even for men of science to fail to apprehend pre- 

 cisely what it is that is effected by this unification of diverse 

 phenomena through their reduction to a common law. I 

 give one example of what appears to me to be such a misap- 

 prehension. The question (to which we shall revert later) 

 whether organic phenomena can be 'reduced' to chemical or 

 physical laws, has been much debated of late; if they can, we 



