Viewed from the distance of the moon, the astonishing thing about the earth, catching the breath, is that it is alive. ... It has the organized, self-contained look of a live creature, full of information, marvelously skilled in handling the sun

Animals have genes for altruism, and those genes have been selected in the evolution of many creatures because of the advantage they confer for the continuing survival of the species.

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.

The gift of language is the single human trait that marks us all genetically, setting us apart from the rest of life.

In the fields I know best, among the life sciences, it is required that the most expert and sophisticated minds be capable of changing course - often with a great lurch - every few years.

Statistically, the probability of any one of us being here is so small that you'd think the mere fact of existing would keep us all in a contented dazzlement of surprise.

The earliest sensation at the onset of illness, often preceding the recognition of identifiable symptoms, is apprehension. Something has gone wrong, and a glimpse of mortality shifts somewhere deep in the mind. It is the most ancient of our fears.