I will confess that I have no more sense of what goes on in the mind of mankind than I have for the mind of an ant.

We are, perhaps, uniquely among the earth's creatures, the worrying animal. We worry away our lives, fearing the future, discontent with the present, unable to take in the idea of dying, unable to sit still.

It is from the progeny of this parent cell that we all take our looks; we still share genes around, and the resemblance of the enzymes of grasses to those of whales is in fact a family resemblance.

All of today's DNA, strung through all the cells of the earth, is simply an extension and elaboration of [the] first molecule.

Medical knowledge and technical savvy are biodegradable. The sort of medicine that was practiced in Boston or New York or Atlanta fifty years ago would be as strange to a medical student or intern today as the ceremonial dance of a !Kung San tribe would seem to a rock festival audience in Hackensack.

Worrying is the most natural and spontaneous of all human functions.

I maintain, despite the moment's evidence against the claim, that we are born and grow up with a fondness for each other, and we have genes for that. We can be talked out of it, for the genetic message is like a distant music, and some of us are hard-of-hearing. Societies are noisy affairs, drowning out the sound of ourselves and our connection.