Music is the effort we make to explain to ourselves how our brains work. We listen to Bach transfixed because this is listening to a human mind.

Any species capable of producing, at this earliest, juvenile stage of its development... the music of Johann Sebastian Bach, cannot be all bad.

It is a distortion, with something profoundly disloyal about it, to picture the human being as a teetering, fallible contraption, always needing watching and patching, always on the verge of flapping to pieces.

We carry stores of DNA in our nuclei that may have come in, at one time or another, from the fusion of ancestral cells and the linking of ancestral organisms in symbiosis. Our genomes are catalogues of instructions from all kinds of sources in nature, filed for all kinds of contingencies.

We are not like the social insects. They have only the one way of doing things and they will do it forever, coded for that way. We are coded differently, not just for binary choices, go or no-go. We can go four ways at once, depending on how the air feels: go, no-go, but also maybe, plus what the hell let's give it a try.

A multitude of bees can tell the time of day, calculate the geometry of the sun's position, argue about the best location for the next swarm. Bees do a lot of close observing of other bees; maybe they know what follows stinging and do it anyway.

The future is too interesting and dangerous to be entrusted to any predictable, reliable agency. We need all the fallibility we can get. Most of all, we need to preserve the absolute unpredictability and total improbability of our connected minds. That way we can keep open all the options, as we have in the past.

The need to make music, and to listen to it, is universally expressed by human beings. I cannot imagine, even in our most primitive times, the emergence of talented painters to make cave paintings without there having been, near at hand, equally creative people making song. It is, like speech, a dominant aspect of human biology.

Very few recognize science as the high adventure it really is, the wildest of all explorations ever taken by human beings, the chance to glimpse things never seen before, the shrewdest maneuver for discovering how the world works.

I don't want to be reincarnated, that's for sure. When you've had rewarding experiences in your life - a loving family, friends - you don't need additional reassurances that you're going to do something with a new cast of characters. I'd just as soon pass.

It is only when you watch the dense mass of thousands of ants, crowded together around the Hill, blackening the ground, that you begin to see the whole beast, and now you observe it thinking, planning, calculating. It is an intelligence, a kind of live computer, with crawling bits for its wits.

We tend to think of our selves as the only wholly unique creations in nature, but it is not so. Uniqueness is so commonplace a property of living things that there is really nothing at all unique about it. A phenomenon can't be unique and universal at the same time.

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.

A lot of people fear death because they think that so overwhelming an experience has to be painful, but I've seen quite a few deaths, and, with one exception, I've never known anyone to undergo anything like agony. That's amazing when you think about it. I mean, how complicated the mechanism is that's being taken apart.

Most of the time I've worked in labs if I didn't encounter something in a week entirely unexpected and surprising I'd consider it a lost week. Lots of that is due to mistakes and stupidity, but it could open a new line of inquiry. Something really good turns up once in a hundred times, but it makes the whole day worthwhile.

The dilemma of modern medicine, and the underlying central flaw in medical education and, most of all, in the training of interns, is the irresistible drive to do something, anything. It is expected by patients and too often agreed to by their doctors, in the face of ignorance.

As a species, taking all in all, we are still too young, too juvenile, to be trusted. We have spread across the face of the earth in just a few thousand years, no time at all as evolution clocks time, covering all livable parts of the planet, endangering other forms of life, and now threatening ourselves.

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.

Well, biology today as I see it has an amiable look - quite different from the 19th-century view that the whole arrangement of nature is hostile, 'red in tooth and claw.' That came about because people misread Darwin's 'survival of the fittest.'

My father was a doctor, and I admired him and got along well with him. He took me with him on house calls. We were living in Flushing, which was then a sleepy village of 25,000 - before the subway got there. I've been sure I wanted to be a doctor since I was about 12.