SIR J. ARTHUR THOMSON 179 



Ignore the implications these involve, as well as the 

 question of purpose which they necessarily ignore. 



Darwin's magnanimous colleague, Alfred Russel 

 Wallace, went beyond Biology and beyond science 

 when he postulated special "spiritual influxes" to ac- 

 count for various "big lifts" in evolution, such as the 

 emergence of man. He thought that without some 

 such postulate the outcome could not be accounted for 

 In terms of the pre-conditions, but his postulate was a 

 departure from the method of descriptive naturalism 

 which keeps to empirical formulae. Thus the biologist 

 in trying to account for the facts of life keeps to the 

 verifiable factors that are known to be resident in or- 

 ganisms and their surroundings. These factors in- 

 clude : 



(a) Chemical and physical processes, operative in 

 and around organisms; 



(b) Qualities of protoplasm that remain in greater 

 part (at present) irreducible, such as irritability, vital 

 persistence or inertia, growth, development, and varia- 

 bility; 



(c) Resident mental or psychical activities, when 

 these are convincingly recognisable as operative. 



Only when the biologist has exhausted the potency 

 of these verifiable resident factors, is he at liberty to 

 say that this or that fact of life cannot be scientifically 

 accounted for. He must therefore remain radically 

 opposed to every attempt to eke out empirical factors 

 with subsidies from transcendental treasuries. 



Thus the evolutionist vision sees a Creative Purpose 

 that so endowed the primitive irreducibles that the first 

 organisms included for all their descendants freedom 



