Viewed from the distance of the moon, the astonishing thing about the earth, catching the breath, is that it is alive. The photographs show the dry, pounded surface of the moon in the foreground, dry as an old bone. Aloft, floating free beneath the moist, gleaming, membrane of bright blue sky, is the rising earth, the only exuberant thing in this part of the cosmos.

If an idea cannot move on its own, pushing it doesn't help; best to let it lie there.

It is not so bad being ignorant if you are totally ignorant; the hard thing is knowing in some detail the reality of ignorance.

The only solid piece of scientific truth about which I feel totally confident is that we are profoundly ignorant about nature... It is this sudden confrontation with the depth and scope of ignorance that represents the most significant contribution of twentieth-century science to the human intellect.

The greatest single achievement of nature to date was surely the invention of the molecule DNA.

Most things get better by themselves. Most things, in fact, are better by morning.

Ants are so much like human beings as to be an embarrassment. They farm fungi, raise aphids as livestock, launch armies into wars, use chemical sprays to alarm and confuse enemies, capture slaves... They do everything but watch television.