The central task of science is to arrive, stage by stage, at a clearer comprehension of nature, but this does not at all mean, as it is sometimes claimed to mean, a search for mastery over nature.

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.

It is not a simple life to be a single cell, although I have no right to say so, having been a single cell so long ago myself that I have no memory at all of that stage of my life.

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

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.

Of all celestial bodies within reach or view, as far as we can see, out to the edge, the most wonderful and marvellous and mysterious is turning out to be our own planet earth. There is nothing to match it anywhere, not yet anyway.

We need science, more and better science, not for its technology, not for leisure, not even for health or longevity, but for the hope of wisdom which our kind of culture must acquire for its survival.