Because we humans are big and clever enough to produce and utilize antibiotics and disinfectants, it is easy to convince ourselves that we have banished bacteria to the fringes of existence. Don't you believe it. Bacteria may not build cities or have interesting social lives, but they will be here when the Sun explodes. This is their planet, and we are on it only because they allow us to be.

It's hard not to be kind of pessimistic about human beings generally, because we do tend to mess things up. If you just look at the history of extinctions, we've killed off an awful lot of animals - and I don't think we're doing a very good job of looking after the planet.

The great failure in education, much of the time, is the lack of excitement and stimulus

In the morning I awoke early and experienced that sinking sensation that overcomes you when you first open your eyes and realize that instead of a normal day ahead of you, with its scatterings of simple gratifications, you are going to have a day without even the tiniest of pleasures; you are going to drive across Ohio.

Anyone who has read my books will know that I don't tend to use guides when I am travelling. It's not a pride thing, but it is certainly a fact.

If you were designing an organism to look after life in our lonely cosmos, to monitor where it is going and keep a record of where it has been, you wouldn't choose human beings for the job. But here's an extrememly salient point: we have been chosen, by fate or Providence or whatever you wish to call it. As far as we can tell, we are the best there is. We may be all there is. It's an unnerving thought that we may be the living universe's supreme achievement and its worst nightmare simultaneously.

In the countryside, litter doesn't have a friend. It doesn't have anybody who's saying, 'Wait a minute, this is really starting to get out of control.'