All this does not contradict the fact that individual physical and mental characteristics are hereditary, and that, by proper selection from among the large series of varying individual forms that occur among all types of people, certain strains might be selected that have admirable qualities, while others might be suppressed that are not so favored.
It is claimed that the practical application has become a necessity because among all civilized nations there is a marked tendency to general degeneration. I do not believe that this assertion has been adequately proved. In modem society the conditions of life have become markedly varied as compared with those of former periods. While some groups live under most favorable conditions, that require active use of body and mind, others live in abject poverty, and their activities have more than ever before been degraded to those of machines. At the same time, the variety of human activities is much greater than it used to be. It is, therefore, quite intelligible that the functional activities of each nation must show an increased degree of differentiation, a higher degree of variability. Even if the general average of the mental and physical types of the people has remained the same, there must be a larger number now than formerly who fall below a certain given low standard, while there must also be more than formerly who exceed a given high standard. The number of defectives can be counted by statistics of poor relief, delinquency and insanity, but there is no way of determining the increase of those individuals who are raised above the norm of a higher standard. Therefore they escape our notice. It may, therefore, very well be that the number of defectives increases, without, however, influencing the value of a population as a whole, because it is merely an expression of an increased degree of variability.
Added to this is the fact that, arbitrarily selected, absolute standards do not retain their significance. Even if no change in the absolute standard should be made, the degree of physical and mental energy required to keep one’s self under modem conditions above a certain minimum of achievement is greater than it used to be. This is due to the greater complexity of our life and to the increasing number of competing individuals. Greater capacity is required to attain a high degree of prominence than was needed in other periods of our history. The claim that we have to contend against national degeneracy must, therefore, be better substantiated than it is now.
This problem is further complicated by the advances of public hygiene, which have had the result of lowering infant mortality, and thus have brought about a change in the composition of the population, in so far as many who would have succumbed to deleterious conditions in early years enter into the adult population and must have an influence upon the general distribution of vitality.
There is still another important aspect of eugenics that should