What an astonishing thing a book is.
Ours is the first generation that has grown up with science-fiction ideas.
We are one species. We are starstuff.
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?
All civilizations become either spacefaring or extinct.
The Earth is a place. It is by no means the only place. It is not even a typical place.