210 HOLISM AND EVOLUTION chap. 



ditive, so that the total activities of a system are repre- 

 sented by the sum of all the individual activities, the situa- 

 tion is entirely different in the case of a living whole. Here 

 all action, as we have seen, is holistic, not only that of the 

 whole itself, but also that of the parts. The stamp of Holism 

 is impressed on the activities of the parts no less than on the 

 individual whole itself. The individual and its parts are 

 reciprocally means and end to one another; neither is merely 

 self-regarding, but each supports the other in the moving 

 dynamic equilibrium which is called life. And so it happens 

 that the central control of the whole also maintains and 

 assists the parts, and the functions of the parts are ever 

 directed towards the conservation and fulfilment of the 

 whole. With this conception of living unity and holistic 

 action in an organism before us, let us try once more to read 

 the riddle of Variation and Natural Selection as the twin 

 factors in Evolution. 



In the first place we realise that each individual organism 

 is a unitary system whose inmost nature is its own balanced 

 self-maintenance and self-development as a whole. Hered- 

 ity is but the expression of this self-conservative character. 

 The organism both as structure and field, while carrying 

 with it the past which is its expressed self, also carries with 

 it the still unrealised future which flows organically from 

 that past, and it maintains a living, moving harmony be- 

 tween the two; its presently existing self is the more or 

 less harmonious realisation of the organic unity of its past 

 and its future in its present. Variations arise as the ten- 

 tacles it throws out under environmental stimulation 

 towards the future, a stretching of hands dimly and uncon- 

 sciously towards future adjustment, welfare and better- 

 ment. These variations, while apparently accidental and 

 uncontrolled, arise from the stimulus of the environ- 

 ment and are under the central control of the organism as 

 a whole. 



Let us for a moment consider the appearance of a small 

 variation. It is really neither spontaneous nor accidental. 

 It is the expression of the moving, developing organism as 



