DEGENERA TION. 



as not being " exact science," yet we may boldly 

 admit the truth of the assertion that we biologists 

 are largely occupied with speculations, hypotheses, 

 and other products of the imagination. All true 

 science deals with speculation and hypothesis, and 

 acknowledges as its most valued servant — its indis- 

 pensable ally and help-meet — that which our German 

 friends^ call " Phantasie " and we ''the Imagination." 

 Our science — biology — is not less exact ; our con- 

 clusions are no less accurate because they are only 

 probably true. They are "probably true" with a 

 degree of probability of which we are fully 

 aware, and which is only somewhat less than the 

 probability attaching to the conclusions of other 

 sciences which are commonly held to be " exact." 

 These remarks are addressed to an Association 

 for the advancement of science — of science which 

 flourishes and progresses by the aid of suppositions 

 and the working of the imagination. The Association 

 has been holding its annual sitting in various parts of 

 the British Islands for more than thirty years, and yet 

 it is still a very common and widely spread notion 

 that science, that is to say, true science according to 



^ See Note A. 



B 2 



