14 Darwin’s Predecessors 
Selection in his exposition of the eliminative processes which go on 
in mankind, the suggestive value of his essay is undeniable, as is 
strikingly borne out by the fact that it gave to Alfred Russel Wallace 
also “the long-sought clue to the effective agent in the evolution of 
organic species.” One day in Ternate when he was resting between 
fits of fever, something brought to his recollection the work of Malthus 
which he had read twelve years before. “I thought of his clear 
exposition of ‘the positive checks to increase ’—disease, accidents, 
war, and famine—which keep down the population of savage races to 
so much lower an average than that of more civilized peoples. It 
then occurred to me that these causes or their equivalents are 
continually acting in the case of animals also; and as animals usually 
breed much more rapidly than does mankind, the destruction every 
year from these causes must be enormous in order to keep down the 
numbers of each species, since they evidently do not increase regularly 
from year to year, as otherwise the world would long ago have been 
densely crowded with those that breed most quickly. Vaguely 
thinking over the enormous and constant destruction which this 
implied, it occurred to me to ask the question, Why do some die 
and some live? And the answer was clearly, that on the whole the 
best fitted live. From the effects of disease the most healthy escaped ; 
from enemies the strongest, the swiftest, or the most cunning ; from 
famine the best hunters or those with the best digestion ; and so on. 
Then it suddenly flashed upon me that this self-acting process would 
necessarily «improve the race, because in every generation the inferior 
would inevitably be killed off and the superior would remain—that 
is, the fittest would survive.” We need not apologise for this long 
quotation, it is a tribute to Darwin’s magnanimous colleague, the 
Nestor of the evolutionist camp,—and it probably indicates the line 
of thought which Darwin himself followed. It is interesting also to 
recall the fact that in 1852, when Herbert Spencer wrote his famous 
Leader article on “The Development Hypothesis” in which he 
argued powerfully for the thesis that the whole animate world is 
the result of an age-long process of natural transformation, he wrote 
for The Westminster Review another important essay, “A Theory 
of Population deduced from the General Law of Animal Fertility,” 
towards the close of which he came within an ace of recognising that 
the struggle for existence was a factor in organic evolution. At 
a time when pressure of population was practically interesting men’s 
minds, Darwin, Wallace, and Spencer were being independently led 
from a social problem to a biological theory. There could be no 
better illustration, as Prof. Patrick Geddes has pointed out, of the 
Comtian thesis that science is a “social phenomenon.” 
1 A. R. Wallace, My Life, A Record of Events and Opinions, London, 1905, Vol. 2. 
2 Ibid. Vol. x. p. 361. ; + 1905, Vol. 1, p. 232. 
