THE UNITY OF SCIENCE. 39 



of unity. It is the end towards which our teaching 

 and learning must move, even if the curve be asymp- 

 totic. 



As we have already noted, the study of living crea- 

 tures stands midway between the chemical and phys- 

 ical sciences, which are in a sense beneath it, and the 

 mental and social sciences, which are in a sense 

 above it ; there are lights from below and lights from 

 above; and to attempt to shut out either means un- 

 necessary obscurity. The living organism is a syn- 

 thesis, whose secret has certainly not been solved, 

 but we are surely saved from some misunderstand- 

 ings of it by the results of other sciences than Bi- 

 ology. 



Thus, there comes to the aid of the biologist or 

 any other scientific worker, this criterion: Am I, 

 as a thinker, teacher, and investigator, recognising, 

 respecting, doing no violence to, the unity of science f 

 Am I recognising other disciplines, other bodies of 

 thought, as I wish that they should recognise mine? 

 Even more positively, the criterion might read: 

 Does this piece of work in any way tend to the real- 

 isation of the Unity of Science ? 



UNITY OF NATURE. 



A third unity may perhaps be spoken of as 

 the unity of nature — by which we mean to refer 

 both to the unity of the particular subject of 

 scientific enquiry, and to the unity of the whole 

 system of things. To the psychologist, the unity 

 which must not be lost sight of is that of the person- 

 ality which he is studying. To the biologist, the 

 unity which cannot be ignored without fallacy is 

 the unity of the organism. But besides these there 

 is the unity of the whole system of nature in which 



