BIOLOGICAL PHILOSOPHY 433 



approach; and this contains elements of the greatest importance to our 

 philosophy and to our practical outlook. One is that the universe is not 

 dualistic but monistic; another is the incorporation of values within the 

 scientific picture, and a reconciliation of their absoluteness in principle 

 with their relativity in practice; a third is the real existence of progress in 

 evolution; a fourth is the complete and sole responsibility of man for achiev- 

 ing any further progress that may be made on this planet, and the falsity 

 of all his attempts to shift any of the burden of his responsibilities onto 

 the shoulders of outside powers; and a fifth is the establishment of the de- 

 veloped human personality as the highest product of the universe (or at 

 least the highest product of which we have any knowledge), with all the 

 implications of this fact for our social and political philosophy. 



DARWIN IS VINDICATED 



Let me take these points one by one, to show their interconnection. The 

 way of advance for truth is in general the same as the way of advance for 

 existing life: of two alternatives, one dies out, not because the other destroys 

 it directly, but because it is less fitted to survive. Even after Copernicus, 

 the doctrine that the sun goes round the earth could still be logically main- 

 tained. But it demanded enormous complexity of epicycle upon epicycle. 

 The rival theory that the earth goes round the sun was far simpler and more 

 satisfying; in the climate provided by developing civilization it survived, 

 the other simply died out of human thinking. 



The monistic, unitary vaew of the universe will survive for the same kind 

 of reason. Our scientific knowledge now permits us to assert definitely that 

 there is no break in the continuity of phenomena. All matter, living or life- 

 less, is composed of the same units — all the millions of diff"erent lifeless sub- 

 stances, as well as of living species, are made of different combinations of 

 still more elementary particles (or "Wavicles"). In reproduction, there is 

 no moment at which life enters; there is continuity of life between the off- 

 spring and its parent or parents. The offspring is merely a detached portion 

 of the parental living svibstance. Nowhere in the transformation of micro- 

 scopic ovum to adult human being is there a break at which one can say 

 "here mind appears," or "there personality enters"; development is con- 

 tinuous. 



It is the same with the vast process of organic evolution. Here too grad- 

 ualness and continuity reign; there is no moment at which we can say that 

 reptile ends or bird begins, no definite demarcation between man and not- 

 man, no sharp line at which we must or indeed could postulate the sudden 

 injection of thought or soul into evolving life. The ideas of evolution by 

 brusque mutations of large extent have disappeared: with the new knowl- 

 edge of the last twenty years the overwhelming consensus of biology has 

 returned to support Darwin's original view of the extreme gradualness of 

 all evolutionary change. 



