ESSAY-REVIEWS 137 



Artificial pathogenesis, intimately connected with Loeb's name, has revealed a 

 chemical mechanism in the fertilising action of the spermatazoon. Other 

 chemical mechanisms stand declared in the action of various salt solutions on 

 developing eggs, and in the chemistry of immunity. The vitalist can admit 

 physico-chemico "sets" in organisms to respond to stimuli — and plenty of them. 

 Is it so certain, besides, that if our planetary observer so perfected his instruments 

 that he could observe human action, he might not be tempted to regard the effects 

 of rain on the populations of cities as negative aqua-tropism, and the influence of 

 the summer sun as positive heliotropism ? The perfection of human contrivance 

 secures the perfect setting of mechanisms : the gramophone is " set " to deliver a 

 tune when a catch is released. In the sphere of human invention the greater 

 the distribution and perfection of delicately "set" mechanisms, the more evident 

 the extra-mechanical agency. There still remains the possibility, however, that 

 the vitalist is the victim of a false analogy and that the mechanist is right. 



When the human mind is confronted with an impasse only resolvable by an 

 indefinite analytical regress, and perhaps not then resolvable, it seeks for some 

 strategical point of view that will make it independent of imperfect knowledge. 

 Vitalism has endeavoured to demonstrate that no physiological or physicochemical 

 machinery could be solely responsible for the morphogenetic or physiological 

 processes of the organism or for the characteristic behaviour of the animal. If it 

 could be demonstrated that any reactions of living things are of such a sort that 

 purely physico-chemico processes could not, from their very nature, completely 

 account for them, the vitalist would occupy a strategic point that would enable 

 him to disregard the argument that complete knowledge might fill all present 

 gaps with a purely physico-chemico filling. If the nature of physico-chemico 

 forces be such that they could not produce some of the results evident in the 

 organism, vitalism can obviously dispense with the complete description of life- 

 activities and affirm that an extra-mechanical factor is present. The argument 

 with a most general appeal is drawn from animal behaviour and particularly from 

 animal behaviour in the higher part of the animal scale. This involves a factor 

 that appears, whatever the reality may be, to be extra-mechanical and to control, 

 in some measure, the activity of the organism. This factor is, of course, con- 

 sciousness, which, wherever any particular observer may place its point of origin 

 in the evolutionary series, must be assumed to exist in, at any rate, higher animals 

 like mammals and birds. Many writers attempt to separate the mechanico- 

 vitalistic problem entirely from consciousness. Thus, Prof. Schafer distinguishes, 

 in his Presidential Address to the British Association of 191 2, between the "soul" 

 and the " problems of life " that " are essentially problems of matter." Now, the 

 psychical element appears in connection with life. The morphogenetic processes 

 converge on the production of an animal that can "behave," and consciousness 

 appears in connection with this behaviour. It seems very arbitrary to make 

 consciousness, which appears quite continuous with the whole vital process, a 

 strict dividing-line between the purely physicochemical and the mechanical plus 

 an extra-mechanical agency. The lower down the scale of life the emergence 

 of consciousness is placed, the more arbitrary does the distinction become. 

 Amoeba and paramcecium cannot be positively credited with consciousness, but 

 neither can it be positively denied that there are good grounds for such crediting. 

 It would be unsafe to put any lower limit to genetic psychology. In any case it 

 is at least as unsatisfactory to regard, with Sir Noel Paton (in "A Physiologist's 

 View of Life and Mind" in the Hibbert Journal for January 191 5), consciousness 

 only as an epi-phenomenon linked to the more complexly developed living 



