Taking this view of human duty in regard to the rational co-operation with nature in the evolution of the human race, it became of the first importance to rescue the control of the generation of offspring from mere blind brute passion, and to transfer it to the reason and to the intelligence; to impress on parents the sacredness of the parental office, the tremendous responsibility of the exercise of the creative function.  And since, further, one of the most pressing problems for solution in the older countries is that of poverty, the horrible slums and dens into which are crowded and in which are festering families of eight and ten children, whose parents are earning an uncertain 10s., 12s., 15s., and 20s. a week; since an immediate palliative is wanted, if popular risings impelled by starvation are to be avoided; since the lives of men and women of the poorer classes, and of the worst paid professional classes, are one long, heart-breaking struggle “to make both ends meet and keep respectable”; since in the middle class marriage is often avoided, or delayed till late in life, from the dread of the large family, and late marriage is followed by its shadow, the prevalence of vice and the moral and social ruin of thousands of women; for these, and many other reasons, the teaching of the duty of limiting the family within the means of subsistence is the logical outcome of Materialism linked with the scientific view of evolution, and with a knowledge of the physical law, by which evolution is accelerated or retarded.  Seeking to improve the physical type, scientific Materialism, it seemed to me, must forbid parentage to any but healthy married couples; it must restrict childbearing within the limits consistent with the thorough health and physical well-being of the mother; it must impose it as a duty never to bring children into the world unless the conditions for their fair nurture and development are present.  Regarding it as hopeless, as well as mischievous, to preach asceticism, and looking on the conjunction of nominal celibacy with widespread prostitution as inevitable, from the constitution of human nature, scientific Materialism—­quite rationally and logically—­advises deliberate restriction of the production of offspring, while sanctioning the exercise of the sexual instinct within the limits imposed by temperance, the highest physical and mental efficiency, the good order and dignity of society, and the self-respect of the individual.

In all this there is nothing which for one moment implies approval of licentiousness, profligacy, unbridled self-indulgence.  On the contrary, it is a well-considered and intellectually-defensible scheme of human evolution, regarding all natural instincts as matters for regulation, not for destruction, and seeking to develop the perfectly healthy and well-balanced physical body as the necessary basis for the healthy and well-balanced mind.  If the premises of Materialism be true, there is no answer to the Neo-Malthusian conclusions; for even