6 READINGS IN EVOLUTION, GENETICS, AND EUGENICS 
with a large group of phenomena consistently arranged and properly 
classified. The discussion which followed the publication of Darwin’s 
‘Origin of Species’ lasted for nearly a generation, but it is now practi- 
cally closed, so far as any attempt to discredit evolution as a true 
scientific generalization is concerned. Scientists are no longer ques- 
tioning the fact of evolution; they are busied rather with the attempt 
to further explore and more perfectly understand the operation of the 
factors that are at work to produce that development of animals and 
plants which we call organic evolution.’”’—Maynard M. Metcalf, An 
Outline of the Theory of Organic Evolution (1911), pp. xxii-xxiii. 
“Biologists turned aside from general theories of evolution and 
their deductive application to special problems of descent, in order to 
take up objective experiments on variation and heredity for their own 
sake. This was not due to any doubts concerning the reality of 
evolution or to any lack of interest in its problems. It was a policy 
of masterly inactivity deliberately adopted; for further discussions 
concerning the causes of evolution had clearly become futile until a 
more adequate and critical view of existing genetic phenomena had 
been attained.’’—E. B. Wilson (address as president of the American 
Association for the Advancement of Science, 1914). 
“The theory of development, as it was revived by Darwin nearly 
half a century ago, is in its modern form prevailingly unhistorical. 
True, it has forced beneath its sceptre the methods of investigation 
of all the sciences which deal with the living world and to-day almost 
completely controls scientific thought... .. And yet science does 
not sincerely rejoice in its conquests. Only a few incorrigible and 
uncritically disposed optimists steadfastly proclaim what glorious 
progress we have made; otherwise, in scientific as in lay circles, there 
prevails a widespread feeling of uncertainty and doubt. Not as 
though the correctness of the principle of descent were seriously 
questioned; rather does the conviction steadily grow that it is 
indispensable for the comprehension of living nature, indeed self- 
evident.”—Gustav Steinmann (translated by W. B. Scott from 
Die Abstammungslehre [1908], pp. 1-2). 
“The many converging lines of evidence point so clearly to the 
central fact of the origin of forms of life by an evolutionary process 
that we are compelled to accept this deduction, but as to almost all 
the essential features, whether of cause or of mode, by which specific 
