physical or mental, and will doubtless find means to encourage the
increase of families that are well endowed by Nature.

Assuming that a nation as a whole prefers a policy of this kind, and
aims at such an equilibrium of births and deaths as will set free the
energies of the people for the higher objects of civilised life, how
will it escape the cacogenic effects of family restriction in the better
classes combined with reckless multiplication among the refuse which
always exists in a large community? This is a problem which has not yet
been solved. Public opinion is not ready for legislation against the
multiplication of the unfit, and it is not easy to see what form such
legislation could take. Many of the very poor are not undesirable
parents; we must not confound economic prosperity with biological
fitness. The 'submerged tenth' should be raised, where it is possible,
into a condition of self-respect and responsibility; but they must not
be allowed to be a burden upon the efficient; and the upper and middle
classes should simplify their habits so far as to make marriage and
parenthood possible for the young professional man. Special care should
be taken that taxation is so adjusted as not to penalise parenthood in
the socially valuable middle class.

For some time to come we are likely to see, in all the leading nations,
a restricted birth-rate, prompted by desire for social betterment,
combined, however, with concessions to the rival policy of commercial
expansion, growing numbers, and military preparation. The nations will
not cease to fear and suspect each other in the twentieth century, and
any one nation which chooses to be a nuisance to Europe will keep back
the progress and happiness of the rest. The prospect is not very bright;
a too generous confidence might betray some nation into irretrievable
disaster. But the bracing influence of national danger may perhaps be