We have heard the rationales offered by the nuclear superpowers. We know who speaks for the nations. But who speaks for the human species? Who speaks for Earth?

Human beings grew up in forests; we have a natural affinity for them. How lovely a tree is, straining toward the sky.

Not explaining science seems to me perverse. When you're in love, you want to tell the world.

Whenever our ethnic or national prejudices are aroused, in times of scarcity, during challenges to national self esteem or nerve, when we agonize about our diminished cosmic place and purpose, or when fanaticism is bubbling up around us - then, habits of thought familiar from ages past reach for the controls.

By looking far out into space we are also looking far back into time, back toward the horizon of the universe, back toward the epoch of the Big Bang.

The very act of understanding is a celebration of joining, merging, even if on a very modest scale, with the magnificence of the Cosmos.

Books break the shackles of time, proof that humans can work magic.