When human beings have been fascinated by the contemplation of their own hearts, the more intricate biological pattern of the female has become a model for the artist, the mystic, and the saint. When mankind turns instead to what can be done, altered, built, invented, in the outer world, all natural properties of men, animals, or metals become handicaps to be altered rather than clues to be followed.

For the human species to evolve, the conversation must deepen.

The negative cautions of science are never popular.

Children not only have to learn what their parents learned in school, but also have to learn how to learn. This has to be recognized as a new problem which is only partly solved.

Pigs and cows and chickens and people are all competing for grain.

The anonymity of the city is one of its strengths as well as - carried too far - one of its weaknesses.

The institution of marriage in all societies is a pattern within which the strains put by civilization on males and females alike must be resolved, a pattern within which men must learn, in return for a variety of elaborate rewards, new forms in which sexual spontaneity is still possible, and women must learn to discipline their receptivity to a thousand other considerations.