The bearing of natural selection on the present-day evolution of the human race, particularly in the United States of America, must be reviewed in a few closing paragraphs.
Selection by death may result either from inadequate food supply, or from some other lethal factor. The former type, although something of a bugaboo ever since the time of Malthus, has in reality relatively little effect on the human race at present. Non-sustentative lethal selection in man is operating chiefly through zymotic diseases and the bad hygiene of the mentally inferior.
Reproductive selection is increasingly effective and its action is such as to cause grave alarm both through the failure of some to marry properly (sexual selection) and the failure of some to bear enough children, while others bear too many (fecundal selection). It is obvious that the racial result of this process will depend on what kind of people bear and rear the most children; and it has been shown that in general the larger families are in the section of the population that makes fewer contributions to human prosperity and happiness, while those endowed with great gifts, who ought to be transmitting them to their children, are in many cases not even reproducing their own number.
Natural selection raised man from apehood to his present estate. It is still operating on him on a large scale, in several ways, but in none of these ways is it now doing much actually to improve the race, and in some ways, owing to man's own interference, it is rapidly hastening race degeneracy.
CHAPTER VII
ORIGIN AND GROWTH OF THE EUGENICS MOVEMENT
"Eugenics," wrote Francis Galton, who founded the science and coined the name, "is the study of agencies under social control that may improve or impair the racial qualities of future generations, either physically or mentally." The definition is universally accepted, but by its use of the word "study" it defines a pure science, and the present book is concerned rather with the application of such a science. Accepting Galton's definition, we shall for our purposes slightly extend it by saying that applied eugenics embraces all such measures, in use or prospect either individually or collectively, as may improve or impair the racial qualities of future generations of man, either physically or mentally, whether or not this was the avowed purpose.
It is one of the newest of sciences. It was practically forced into existence by logical necessity. It is certainly here to stay, and it demands the right to speak, in many cases to cast the deciding vote, on some of the most important questions that confront society.
The science of eugenics is the natural result of the spread and acceptance of organic evolution, following the publication of Darwin's work on The Origin of Species by Means of Natural Selection, in 1859. It took a generation for his ideas to win the day; but then they revolutionized the intellectual life of the civilized world. Man came to realize that the course of nature is regular; that the observed sequences of events can be described in formulas which are called natural laws; he learned that he could achieve great results in plant and animal breeding by working in harmony with these laws. Then the question logically arose, "Is not man himself subject to these same laws? Can he not use his knowledge of them to improve his own species, as he has been more or less consciously improving the plants and animals that were of most value to him, for many centuries?"