22 UNIVERSITY OF MISSOURI BULLETIN 



empirical knowledge they were not, and could not be, carried 

 out convincingly in detail. From Descartes's or even New- 

 ton's general laws of motion it was not found possible to de- 

 duce any empirically correct and predictive special laws for all 

 the diverse classes of phenomena. In certain branches of 

 physics, indeed, — in celestial mechanics, and even in optics, — 

 it was, for fairly obvious reasons, practicable to find in certain 

 laws of motion a common denominator, so to say, for a con- 

 siderable variety of superficially dissimilar facts. But chem- 

 istry, physiology, embryology, phylogeny remained essentially 

 ununified, in spite of some energetic efforts of various seven- 

 teenth century scientists in that direction, and in spite of some 

 special discoveries that seemed to encourage a hope for the 

 success of the enterprise. Most of the sciences made better 

 progress by not worrying too much about the unity of science, 

 by segregating each its own class of phenomena and arriving 

 at partial generalizations about that class by means of patient 

 inductive inquiry. The one science, which was virtually the 

 ideal of Descartes, of Hobbes, of Leibniz, was broken up into 

 many highly specialized sciences ; and each specialist was con- 

 tent to deal with the unresolved peculiarities of his own par- 

 ticular type of subject matter. Each discipline had its char- 

 acteristic categories and primary notions, its own technical 

 vocabulary of general terms. The chemist was not in the 

 habit of regarding himself as only a slightly differentiated 

 and specialized breed of physicist, the biologist did not ordin- 

 arily conceive his studies to be only a subsidiary branch of 

 chemistry, the psychologist was quite unlikely to fancy him- 

 self a biologist of somewhat narrow view, and the economist 

 and the theorist about society, though they may have not in- 

 frequently recognized that they dealt primarily with a sub- 

 division of psychology, certainly seldom thought of them- 

 selves as chemists twice or physicists thrice removed. The 

 chemist could not borrow from the physicist, nor the biologist 

 from the chemist, nor the sociologist from the biologist, laws 

 which would spare him the necessity of establishing all the 



