714 ON FORM AND MECHANICAL EFFICIENCY [ch. 



in this limited and subordinate sense, that they are farts of a 

 whole which, when it loses its composite integrity, ceases to 

 exist. 



The biologist, as well as the philosopher, learns to recognise 

 that the whole is not merely the sum of its parts. It is this, and 

 much more than this. For it is not a bundle of parts but an 

 organisation of parts, of parts in their mutual arrangement, 

 fitting one with another, in what Aristotle calls "a single and 

 indivisible principle of unity" ; and this is no merely metaphysical 

 conception, but is in biology the fundamental truth which lies at 

 the basis of Geoffroy's (or Goethe's) law of "compensation," or 

 "balancement of growth." 



Nevertheless Darwin found no difficulty in believing that 

 "natural selection will tend in the long run to reduce any fart 

 of the organisation, as soon as, through changed habits, it becomes 

 superfluous : without by any means causing some other part to 

 be largely developed in a corresponding degree. And conversely, 

 that natural selection may perfectly well succeed in largely deve- 

 loping an organ without requiring as a necessary compensation 

 the reduction of some adjoining part*." This view has been 

 developed into a doctrine of the "independence of single char- 

 acters" (not to be confused with the germinal "unit characters" 

 of Mendelism), especially by the palaeontologists. Thus Osborn 

 asserts a "principle of hereditary correlation," combined with a 

 " principle of hereditary separability whereby the body is a colony, 

 a mosaic, of single individual and separable charactersf-" 

 I cannot think that there is more than a small element of truth 

 in this doctrine. As Kant said, "die Ursache der Art der Existenz 

 bei jedem Theile eines lebenden Korpers ist im Ganzen enthalten..'^ 

 And, according to the trend or aspect of our thought, we may 

 look upon the co-ordinated parts, now as related and fitted to the 

 end or function of the whole, and now as related to or resulting 

 from the physical causes inherent in the entire system of forces 

 to which the whole has been exposed, and under whose influence 

 it has come into being J. 



* Origin of Species, 6th ed. p. 118. 



t Atner. Naturalist, April, 1915, p. 198, etc. Cf. infra, p. 727. 



J Driesch sees in "Entelechy" that something which differentiates the whole 



