Montaigne simply turns his mind loose and writes whatever he feels like writing. Mostly, he wants to say that reason is not a special, unique gift of human beings, marking us off from the rest of nature.

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.

As evolutionary time is measured, we have only just turned up and have hardly had time to catch breath, still marveling at our thumbs, still learning to use the brand-new gift of language. Being so young, we can be excused all sorts of folly and can permit ourselves the hope that someday, as a species, we will begin to grow up.

Survival, in the cool economics of biology, means simply the persistence of one's own genes in the generations to follow.

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.

I do not agree with this century's fashion of running down the human species as a failed try, a doomed sport. At our worst, we may be going through the early stages of adolescence, and everyone remembers what that is like.

We are built to make mistakes, coded for error.