As agonizing a disease as cancer is, I do not think it can be said that our civilization is threatened by it. ... But a very plausible case can be made that our civilization is fundamentally threatened by the lack of adequate fertility control. Exponential increases of population will dominate any arithmetic increases, even those brought about by heroic technological initiatives, in the availability of food and resources, as Malthus long ago realized.

Human history can be viewed as a slowly dawning awareness that we are members of a larger group Groups of people from divergent ethnic and cultural backgrounds working in some sense together [is] surely a humanizing and character building experience. If we are to survive, our loyalties must be broadened further, to include the whole human community, the entire planet Earth.

We live in a vast and awesome universe in which, daily, suns are made and worlds destroyed, where humanity clings to an obscure clod of rock.

The visions we offer our children shape the future.

Life is but a momentary glimpse of the wonder of this astonishing universe, and it is sad to see so many dreaming it away on spiritual fantasy.

Stars are phoenixes, rising from their own ashes.

I don't want to believe. I want to know.