"We are just beginning to learn that our same old habits, like the exploitation of nonrenewable resources, may make us at one with the auk and the dodo."

“Freud's prescription for personal happiness as consisting of work and love must be taken with the proviso that the work has to be loved, and the love has to be worked at.”

“The principal difference between love and hate is that love is an irradiation, and hate is a concentration. Love makes everything lovely; hate concentrates itself on the object of its hatred. All the fearful counterfeits of love — possessiveness, lust, vanity, jealousy — are closer to hate: they concentrate on the object, guard it, suck it dry.”

“The beauty of “spacing” children many years apart lies in the fact that parents have time to learn the mistakes that were made with the older ones — which permits them to make exactly the opposite mistakes with the younger ones.”

“The three hardest tasks in the world are neither physical feats nor intellectual achievements, but moral acts: to return love for hate, to include the excluded, and to say, "I was wrong.”

“An idealist believes the short run doesn’t count. A cynic believes the long run doesn’t matter. A realist believes that what is done or left undone in the short run determines the long run.”

“A cynic is not merely one who reads bitter lessons from the past; he is one who is prematurely disappointed in the future.”