n] BIOLOGICAL FOUNDATIONS 33 



we shall have to show some of the chief difficulties 

 which attend upon this point of view; and finally, 

 having thus cleared the decks for action, we shall be 

 able to take up our subject anew from its historical 

 and logical beginnings. 



A normal adult man or woman is an organism, 

 whose complicated and varied parts are almost all 

 designed for one end to prolong the existence of the 

 whole to which they belong 1 . It is in fact a machine 

 which has the power of running itself, independent, 

 within wide limits, of what is happening in the rest 

 of the world. Unlike our artificial machines, however, 

 whose working is constant, and whose only change is 

 one of wearing-down, the running of the organic 

 machine leads to changes in the actual structure of 

 the machine, and so to changes in its working. We 

 develop of necessity, of necessity we age, and at the 

 last we die. But we remain the same individual 

 throughout on that all common use is agreed. Till 

 death, when we obviously cease to be whatever we 

 have been before, we preserve our individuality in 

 spite of all fundamental differences in appearance 

 and behaviour. But as to our nature before birth, 

 there the common view is at a loss ; its uncertainty 



1 Those which do not serve this end (with the exception of some 

 which appear to be "accidental" by-products due to the interaction 

 of the purposeful factors) are of course destined to help in repro- 

 duction. 



H. 3 



