e in the birth-rate among
superior people must depend largely on a change in public sentiment.
Such a change may be brought about in many ways. The authority of
religion may be invoked, as it is by the Roman Catholic and Mormon
churches[127] whose communicants are constantly taught that fecundity is
a virtue and voluntary sterility a sin. Unfortunately their appeal fails
to make proper discriminations. Whatever may be the theological reasons
for such an attitude on the part of the churches, its practical eugenic
significance is clear enough.

Nothing can be more certain than that, if present conditions continue,
Roman Catholics will soon be in an overwhelming preponderance in the
eastern United States, because of the differential birth-rate, if for no
other reason; and that the Mormon population will steadily gain ground
in the west. Similarly, it is alleged that the population of France is
gradually assuming the characteristics of the Breton race, because that
race is the notably fecund section of the population, while nearly all
the other components of the nation are committing race suicide (although
not so rapidly as is the old white stock in New England). Again, the
role of religion in eugenics is shown in China, where ancestor worship
leads to a desire for children, and makes it a disgrace to be childless.
A process analogous to natural selection applies to religions much as it
does to races; and if the Chinese religion, with its requirement of a
high birth-rate, and the present-day American Protestant form of the
Christian religion, with its lack of eugenic teaching, should come into
direct competition, under equal conditions of environment, it is obvious
that the Chinese form would be the eventual survivor, just because its
adherents would steadily increase and those of its rival would as
steadily decrease. Such a situation may seem fanciful; yet the leaders
of every church may well consider whether the religion which they preach
is calculated to fill all the needs of its adherents, if it is silent on
the subject of eugenics.

The influence of economic factors on the birth-rate is marked. The
child, under modern urban conditions, is not an economic asset, as he
was on the farm in earlier days. He is an economic liability instead.
And with the constant rise of the standard of living, with the increase
of taxation, the child steadily becomes more of a liability. Many
married people desire children, or more childre