"The more rapidly a civilization progresses, the sooner it dies for another to rise in its place."

"Birth-control is effecting, and promising to effect, many functions in our social life."

"When love is suppressed hate takes its place."

"There is a very intimate connection between hypnotic phenomena and religion."

"The parents have not only to train their children: it is of at least equal importance that they should train themselves."

"Of woman as a real human being, with sexual needs and sexual responsibilities, morality has often known nothing."

"The place where optimism flourishes most is the lunatic asylum."

"Socialism also brings us up against the hard rock of eugenic fact which, if we neglect it, will dash our most beautiful social construction to fragments."

"The husband - by primitive instinct partly, certainly by ancient tradition - regards himself as the active partner in matters of love and his own pleasure as legitimately the prime motive for activity."

"It is on our failures that we base a new and different and better success."

"For every fresh stage in our lives we need a fresh education, and there is no stage for which so little educational preparation is made as that which follows the reproductive period."

"The sun, the moon and the stars would have disappeared long ago, had they happened to be within reach of predatory human hands."

"In the early days of Christianity the exercise of chastity was frequently combined with a close and romantic intimacy of affection between the sexes which shocked austere moralists."

"The sanitary and mechanical age we are now entering makes up for the mercy it grants to our sense of smell by the ferocity with which it assails our sense of hearing."

"Every man of genius sees the world at a different angle from his fellows, and there is his tragedy."

"Education, whatever else it should or should not be, must be an inoculation against the poisons of life and an adequate equipment in knowledge and skill for meeting the chances of life."

"It is becoming clear that the old platitudes can no longer be maintained, and that if we wish to improve our morals we must first improve our knowledge."

"What we call progress is the exchange of one nuisance for another nuisance."

"No act can be quite so intimate as the sexual embrace."

"In philosophy, it is not the attainment of the goal that matters, it is the things that are met along the way."

"The average husband enjoys the total effect of his home but is usually unable to contribute any of the details of work and organisation that make it enjoyable."

"Still, whether we like it or not, the task of speeding up the decrease of the human population becomes increasingly urgent."

"At the present day the crude theory of the sexual impulse held on one side, and the ignorant rejection of theory altogether on the other side, are beginning to be seen as both alike unjustified."

"Failing to find in women exactly the same kind of sexual emotions, as they find in themselves, men have concluded that there are none there at all."

"There is nothing that war has ever achieved we could not better achieve without it."