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

If one cannot state a matter clearly enough so that even an intelligent twelve-year-old can understand it, one should remain within the cloistered walls of the university and laboratory until one gets a better grasp of one's subject matter.

In contrast to our own social environment which brings out different aspects of human nature and often demonstrated that behavior which occurs almost invariably in individuals within our society is nevertheless due not to original nature but to social environment; and a homogeneous and simple development of the individual may be studied.

Earth Day is the first holy day...and is devoted to the harmony of nature... The celebration offends no historical calendar, yet it transcends them all.

In this country, some people start being miserable about growing old while they are still young.

Our human situation no longer permits us to make armed dichotomies between those who are good and those who are evil, those who are right and those who are wrong. The first blow dealt to the enemy's children will sign the death warrant of our own.

Sometimes, instead of helping people to advance, a discovery or an invention holds them back.