The psychical characters of races are in part original, and in part acquired through adaptation. These persist in a race as long as such mesological adaptation lasts; they vary with modifications of the conditions of life, including social activities and inter-racial relations.
In mixed unions, amongst different races, there are always some which are more vigorous, biologically and mentally, more fully developed, which impress their characters upon their descendants. For the vitality and well-being of mixed or metamorphic populations a certain amount of difference amongst the parent races is necessary, but too great a difference is injurious to the offspring.
The offspring of mixed unions present in their psychology a mixture, again a combination or fusion of the mental characters of the parent races: sometimes certain psychical characters of a race become the dominant characters.
All ethnic groupings have their destiny marked out by the grade attained in the human psycho-physical hierarchy. Nevertheless, it is necessary that each race or nation, when it knows its contribution to the development of universal civilisation, should contemplate the preservation of its own ethnic type. Differentiation amongst peoples is an indispensable factor in human progress.
The science of eugenics should not look for the realisation of a uniform type of man, but vary its aims and methods according to the natural differentiation of races and nations, taking account of ethnic psychology equally with ethnic somatology.
The humanity of the future will be physically and mentally superior to the existing humanity, but the amelioration of the species ought not to aim at the equality of races and populations. These races and populations ought not to lose their acquisition of particular adaptations to different conditions of existence.
A science of universal or common eugenics should allow a eugenic ethnology to exist, which should indicate and facilitate for each race or nation the defence and propagation of its own physical type and its own mentality. The most vigorous and dominant races will always be those which know how to create and preserve in sexual unions their characteristics of structure and culture.
[THE INHERITANCE OF EPILEPSY.]
(Abstract.)