Well-washed and well-combed domestic pets grow dull; they miss the stimulus of fleas.

We greatly want a brief word to express the science of improving stock, which is by no means confined to questions of judicious mating, but which, especially in the case of man, takes cognizance of all influences that tend in however remote a degree to give to the more suitable races or strains of blood a better chance of prevailing speedily over the less suitable than they otherwise would have had. The word eugenics would sufficiently express the idea.

Eugenics is the study of the agencies under social control that may improve or impair the racial qualities of future generations either physically or mentally.

The publication in 1859 of the Origin of Species by Charles Darwin made a marked epoch in my own mental development, as it did in that of human thought generally. Its effect was to demolish a multitude of dogmatic barriers by a single stroke, and to arouse a spirit of rebellion against all ancient authorities whose positive and unauthenticated statements were contradicted by modern science.

All male animals, including men, when they are in love, are apt to behave in ways that seem ludicrous to bystanders.

The phrase 'nature and nurture' is a convenient jingle of words, for it separates under two distinct heads the innumerable elements of which personality is composed. Nature is all that a man brings with himself into the world; nurture is every influence without that affects him after his birth.

Englishmen Francis Galton to describe the "science" of bettering human stock and the elimination of unwanted characteristics... and individuals. Galton proposed societal intervention for the furtherance of "racial quality," maintaining that "Jews are specialized for a parasitical existence upon other nations" and that "except by sterilization I cannot yet see any way of checking the produce of the unfit who are allowed their liberty and are below the reach of moral control.