To fulfil this second law, nature has placed on every normal healthy man
and woman the sacred duty of reproducing their kind. Reproduction as a
physiological process promotes, both directly and indirectly, the
health, happiness and longevity of healthy men and women.

Statistics confirm the popular opinion "that the length of life, to the
enjoyment of which a married person may look forward, is greater than
that of the unmarried, both male and female at the same
age."--(Coghlan).

It is a familiar observation that the mothers of large families of ten
and even twice that number are not less healthy nor shorter lived
because of the children they have borne. Pregnancy is a stimulus to
vitality. Because another life has to be supported, all the vital
powers are invigorated and rise to the occasion--the circulation
increases, the heart enlarges in response to the extra work, and the
assimilative powers of the body are greatly accelerated. During
lactation also, the same extra vital work done is a stimulus to a
physiological activity which is favourable to health and longevity. The
expectancy of life in women is greater than in men all through life, the
difference during the child-bearing period of life being about 2.2 years
in favour of women.

Statistics and physicians from their observation agree in this, that the
bearing of children by normal women, so far from being injurious to
health, is as healthful, stimulating, and invigorating a function as the
blooming of a flower, or the shedding of fruit, and a mother is no worse
for the experience of maternity than is the plant or the tree for the
fruit it bears.