We live in a vast and awesome universe in which, daily, suns are made and worlds destroyed, where humanity clings to an obscure clod of rock.

At the extremes it is difficult to distinguish pseudoscience from rigid, doctrinaire religion.

If chimpanzees have consciousness, if they are capable of abstractions, do they not have what until now has been described as 'human rights'? How smart does a chimp have to be before killing him constitutes murder?

We are rare and precious because we are alive, because we can think as well as we can. We are privileged to influence and perhaps control our future. I believe we have an obligation to fight for life on Earth - not just for ourselves, but for all those, humans and others, who came before us, and to whom we are beholden, and for all those who, if we are wise enough, will come after.

In our time, we have sifted the sands of Mars, we have established a presence there, we have fulfilled a century of dreams!

We can always take but never give.

We are made of star-stuff. Our bodies are made of star-stuff. There are pieces of star within us all.