292 DRIESCH'S THEORIES OF DEVELOPMENT V 



struction of the egg- out of like particles all similarly polarized 

 and all oriented in the same way. 1 



This being so, the first argument based on the ' causal harmony ' 

 will fall to the ground; for this will be given in the initial structure 

 of the egg, and if that may be divided, then the ' causal harmony ' 

 may be divided too. The correct proportionality of the organs 

 of partial larvae, then, offers no peculiar difficulty. The corrobora- 

 tive argument is founded on a consideration of responses to stimuli. 

 This is not a question for the embryologist, but it may be 

 pointed out that there are still physiologists who maintain that 

 even the complex phenomena presented to us in the activities of the 

 nervous system are susceptible of a purely mechanical explanation. 



The second series of objections to the new ' vitalism } is 

 philosophical. Driesch has quoted the authority of Kant and 

 Aristotle in support of his doctrine. The former is, however, 

 rather a difficult witness, as Driesch is well aware. He com-" 

 plains, indeed, that Kant's teleology is descriptive or ' static ' 

 rather than ' dynamic ', as is perfectly true, except in the case 

 of man, a point of which Driesch naturally makes the most. 

 There are no doubt passages where Kant speaks of 'a cause 

 < which brings together the required matter, modifies it, forms it 

 ' and puts it into its appropriate place ', 2 but against these must 

 be set the explicit statement that if the body has an alien 

 principle (the soul) in communion with it, ' the body must either 

 ' be the instrument of the soul which does not make the soul 

 'a, whit more comprehensible ' 3 or be made by the soul, in which 

 case it would not be corporeal at all. ' Vitalism ' can glean small 

 comfort from this. 



Let us turn, then, to the second authority. 



Aristotle's matured reflections on the soul (v//^ 7 /); its nature, 

 functions, and development, are to be found in the treatises 

 De Anima and De Generatione Animalium. 



Soul is defined in the most general way as an activity of 



1 C. M. Child (Biol. Centralbl. xxviii, 1908) has recently published 

 a similar criticism of Driesch's absolutely equipotential systems. Child 

 points out in particular that in the regeneration of the head of Titbularia 

 the proportionality of the parts differs in different regions of the stem, 

 and under different conditions, and cannot therefore always be exact. 

 The equipotentiality of the system is therefore not absolute. 



2 66. 3 65. 



