To like many people spontaneously and without effort is perhaps the greatest of all sources of personal happiness.

Love as a relation between men and women was ruined by the desire to make sure of the legitimacy of children.

When you meet with opposition, even if it should be from your husband or your children, endeavor to overcome it by argument and not by authority, for a victory dependent upon authority is unreal and illusory.

Experience has taught me a technique for dealing with such people [...] I counter the devotees of the Great Pyramid by adoration of the Sphinx; and the devotee of nuts by pointing out that hazelnuts and walnuts are as deleterious as other foods and only Brazil nuts should be tolerated. But when I was younger I had not yet acquired this technique, with the result that my contacts with cranks were sometimes alarming.

Science is what you know, philosophy is what you don't know.

I do not think any reasonable person can doubt that in India, China and Japan, if the knowledge of birth control existed, the birthrate would fall very rapidly

The demand for certainty is one which is natural to man, but is nevertheless an intellectual vice. So long as men are not trained to withhold judgment in the absence of evidence, they will be led astray by cocksure prophets, and it is likely that their leaders will be either ignorant fanatics or dishonest charlatans. To endure uncertainty is difficult, but so are most of the other virtues.