272 ESSAYS OF A BIOLOGIST 



it is led off at a higher level, and we can learn to lead 

 off still more ; and we can make an installation of 

 pipes whereby it can be taken up to the original level, 

 and made to fall through new machines and do any 

 work we may ask of it. 



The mechanism of sublimation, however, deserves 

 a few more words. Recent work in biology has 

 shown that in low forms of animals and in early 

 stages of high forms, the head-region is in a certain 

 sense dominant to the rest, in that it forms first and 

 independently ; but that, once present, it exerts a 

 formative influence upon the rest of the body, keeping 

 the various organs in some way under control, making 

 them different from what they would otherwise have 

 been, and so moulding them to the part of a single 

 and higher whole. 



An extremely similar process is at work in sub- 

 limation. Ideas and ideals can be naturally dominant 

 over others, or they can become dominant through 

 becoming associated with primarily dominant ideas, 

 or by receiving a larger share of attention. Atten- 

 tion, concentration, what you will, is one of the most 

 remarkable mental functions. Not only can the 

 metaphor of intense illumination of a particular field 

 be justly used of it, but we may say that it seems to 

 accelerate the flow of mental process through a par- 

 ticular channel, and so to draw into that channel the 

 contents of other channels in connection with it, 

 just as a rapid flow of water through a pipe sucks in 

 water from connected pipes. 



