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.

We are...capable of using our compassion and our intelligence, our technology and our wealth, to make an abundant and meaningful life for every inhabitant of this planet. To enhance enormously our understanding of the Universe, and to carry us to the stars.

Humans are very good at dreaming, although you'd never know it from your television.

The cosmos is full beyond measure of elegant truths; of exquisite interrelationships; of the awesome machinery of nature.

Ask courageous questions. Do not be satisfied with superficial answers.

As the ancient myth makers knew, we are children equally of the earth and the sky.

My view is that if there is no evidence for it, then forget about it. An agnostic is somebody who doesn’t believe in something until there is evidence for it, so I’m agnostic.