MUTATION THEORY OF EVOLUTION. 391 



I am encouraged to state my views the more boldly because 

 the current theory of evolution has already been challenged by 

 eminent scientists whose researches have taken them no further 

 than the confines of the vegetable and animal kingdom. There 

 are now two distinct theories of organic evolution. In the current 

 theory the idea of continuity or steady progress is the one usually 

 emphasised. " Organic evolution," says Karl Pearson, " is the 

 progressive change of living forms usually associated with the 

 development of complex forms from one or more simple forms." 

 This definition will do as well as any other for our purpose. It 

 indicates clearly enough a gradual progress from the simple to the 

 more complex. 



In opposition to this theory is the mutation or saltation theory 

 of evolution which affirms that, even in the organic world, develop- 

 ment is not continuous ; but " that sudden mutation is the normal 

 way in which nature produces new species and varieties " — that 

 there are breaks, abrupt changes, or leaps. Of this theory Hugo 

 de Vries is one of the most powerful exponents at the present time. 

 In the preface to his work on " Species and Varieties ; their Origin 

 and Mutation," he contrasts the two theories in these words — 

 " The current belief assumes that species are slowly changed into 

 new types. In contradiction to this conception the theory of 

 mutation assumes that new species and varieties are produced 

 from existing forms by sudden leaps." 



Now if such a theory as the mutation theory is applicable 

 at all to the development of plant life, where the cosmic process 

 works without challenge, it ought not to be very difficult to show 

 that it is far more obviously and extensively applicable to the 

 development of intelligent beings for whom, as Huxley says, in 

 his Romanes lecture in 1893, " Social progress means a checking of 

 the cosmic process at every step, and the substitution for it of 

 another which may be called the ethical process." The phrase 

 " cosmic process " has been subjected to searching criticism. It 

 is somewhat vague, though not more so than phrases generally 

 are which attempt to express the nature of ultimate forces. But 

 whether we reject the phrase or not, distinctions between the 

 organic world and the world of human beings can be put into 

 words plain enough. Man is endowed with self-consciousness, 

 animals and plants are not ; man looks before and after, animals 

 and plants do not ; man has the power of reflecting on his own 

 impulses and pronouncing them good or bad, animals and plants 

 have not ; man has the power of constructing ideals and regulating 

 his life by constant reference to these ideals, animals and plants 

 have not. 



All these are essential differences between the organic and the 

 human world which ought to make us far more cautious than 

 Herbert Spencer ever was in applying the principles of organic 

 ■evolution to the social and political development of man. They 

 are differences that point constrainedly, if not quite conclusively, 



