Societies as well as people become afraid of change as they grow older. It's human nature. The young have adventures while the old sit at home and nurture their memories.

If there's one thing we've learnt from the twentieth century, it's that change is continuous and is advancing on a thousand different fronts.

Everyone should find something they love doing. Then work isn't work. It's a part of themselves. Of who they are.

Time and again we fail ... and each time we fail, we rise up again and continue, determined this time to fail better.

One of the most engaging themes in SF is, to my mind, the problem of the hero. How can a hero be human enough for us to care about him, and yet also be capable of doing heroic deeds? One solution is that he or she does not care to be a hero -- echoing Christ's denial on the cross. The tension between ability to act and reluctance to act is where human drama is kindled.

By their very nature utopias are static. They hate change because it's a direct challenge to their fantasy of perfection.

It's an abiding principle that ordinary people who serve the rich and powerful must always be prepared for sudden and unexpected reversals. For the rich and powerful can be unthinkingly cruel and capricious. They can change the lives of their servants on a whim, and think nothing of it.

No matter what cause extremists rally to, they are all driven by the need to stamp their ideology on the rest of us.

Mobs were ugly and vicious but they were also purposeful, congregating around a wound in the populace's psyche like white blood cells around an infection in the body. They were safety valves for frustration and dissatisfaction; they united a population against a real or imagined enemy.

The biosphere was a vast space of possibilities. Billions of years of life on Earth had explored only a small part of that space. So much more could be unlocked with just a small toolkit and a little imagination, and nothing was unnatural because nature was not limited to the variations on a few themes that evolution had so far realised. She dreamed of a thousand Earths, all different. A thousand gardens of plenty, harmonious, burgeoning with wonders.

The past is essentially unknowable: we remake it in our image. Things do not speak for themselves -- we must make them speak.

Our worlds would be drab and poor places if we created things only for reasons of utility.