reproduction, a principle in human affairs is established, and its
decree that individuals shall not mate before a certain age, or not mate
at all, is only a further application of the same principle. By the law
of reproduction a strong instinct, second only in force and universality
to the law of self-preservation, is planted in the sexes, and upon a
blind obedience to this force, the continuity of the race depends.

The tendency in the races of history has been to over-population, or to
a population beyond the food supply, and there is probably no race known
to history that did not at some one period of its rise or fall suffer
from over-population.

States have mostly been concerned, therefore, with restraining or
inhibiting the natural reproductive instinct of their subjects through
marriage laws which protect the State, by fixing paternal
responsibility. There were strong reasons why a State should not be
over-populated, and only one reason why it should not be
under-populated. That one reason was the danger of annihilation from
invasion.

Sparta was said to have suffered thus, because of under-population, and
passed a law encouraging large families. Alexander encouraged his
soldiers to intermarry with the women of conquered races, in order to
diminish racial differences and antagonism, and Augustus framed laws for
the discouragement of celibacy, but no law has ever been passed
decreeing that individuals must mate, or if they do mate that they shall
procreate.

Malthus, the great and good philanthropist of Harleybury, a great
moralist and Christian clergyman, urged that it was people's duty not to