38 PROGRESS OF SCIENCE IN THE CENTURY. 



physiology. Even the frequent break-downs of the 

 a priori methods prompted a posteriori enquiry. 



UNITY OF SCIENCE. 



The second unity — a recognition of which makes 

 for sanity — is the unity of science or knowledge. 

 The sciences in the broadest sense form one body of 

 truth. Blocked apart for practical convenience, 

 treated of in separate books, expounded by different 

 teachers, investigated in different laboratories, they 

 are parts of one discipline, illustrations of one 

 method, expressions of one mood, and attempts to 

 make clear — if never to solve — the one great prob- 

 lem of the Order of Nature. The sciences have their 

 ideal completeness only when inter-related. This is 

 the ideal alike of the philosopher's stone, of the en- 

 cyclopaedic movement, and of the most modern scien- 

 tific synthesis. 



This note of the unity of the sciences is sounded — 

 though so often quickly silenced — in the word Uni- 

 versity. Its value is demonstrated by the history of 

 the sciences, which shows how often a fresh contact 

 between two departments has led to great advances. 

 It becomes insistent when we consider a big subject 

 like the physiology of marine organisms, which there 

 is no hope of understanding except through the com- 

 bined efforts of chemist and physicist, botanist and 

 zoologist, meteorologist and geographer. 



Whether we take a hint from the term " Natural 

 History,^' or from the word " Organisata,'' which 

 Linnaeus used to include both animals and plants, or 

 from Comte's hierarchy of the sciences, or from 

 Caird's essay on the unity of science, or from 

 Spencer's Synthetic Philosophy — ^we have purposely 

 chosen incongruous examples — we hear the same note 



