40 PROGRESS OF SCIENCE IN THE CENTURY. 



part is linked to part by sure, though often subtle 

 bonds in which nude isolation is as rare as a vacuum. 

 In regard to all matters we have many questions to 

 ask, each difficult, each interesting, each often re- 

 quiring special methods of investigation, and in the 

 search of answers we are sometimes apt to forget the 

 unity of the subject. There can be no doubt, for in- 

 stance, that in the eager pursuit of comparative 

 anatomy, or chemical physiology, or any other par- 

 ticular line of biological enquiry, the unity of the 

 organism is often forgotten. The same is true, 

 though perhaps less markedly, in other sciences, 

 where the fascination of some one aspect or method 

 causes the investigator to lose his sense of the unity 

 of his subject. Specialism of enquiry is necessary 

 and valuable, but it loses its virtue if the specialist 

 remain like a beetle in a rut, the sides of which form 

 the horizon. 



Thus we reach a third criterion of scientific work 

 and thought ; we must force upon ourselves the ques- 

 tion Am I studying this whatever it is as I 

 would have myself studied, as a whole, as a unity, 

 and moreover as a part in the great system of things 

 which we call Nature, which is also a Unity ? 



To sum up, there are a certain number of 'isms 

 which we scornfully call fads. They express a loss 

 of perspective, intellectual, emotional, or practical, 

 the dominance of some fixed idea which distorts or 

 obscures vision. It is easy to scoff at one or other of 

 these fads, but the chances are that we are OUT 

 victims. It is more in the line of progress to study 

 their meaning, and then we see that they are often 

 reactions against some denial of the unity of life, the 

 nnity of science, the unity of nature, or some greater 

 unity than these. 



