At its best, SF is the medium in which our miserable certainty that tomorrow will be different from today in ways we can’t predict, can be transmuted to a sense of excitement and anticipation, occasionally evolving into awe. Poised between intransigent skepticism and uncritical credulity, it is par excellence the literature of the open mind.

The most visceral science fiction always takes place in the past and focuses on the humdrum.

You don’t have to burn books to destroy a culture. Just get people to stop reading.

In short, the straw of a manufactured realism with which the sf writer makes his particular literary bricks must be entirely convincing to the reader in it own right, or the whole story will lose its power to convince.

Write me a creature that thinks as well as a man or better than a man, but not like a man.

Literary characters… draw you in and cultivate feelings of friendship on your part. Although, no matter how much you learn about them, how much time you spend with them–how far you can see into their thoughts and words, how they interact with others, their looks, what they wear–they will never, ever know you.

By challenging anthropocentricism and temporal provincialism, science fiction throws open the whole of civilization and its premises to constructive criticism.

“If you ever find yourself coming out of a time machine, run. Run away as fast you can. Don’t stop. Don’t try to talk. Nothing good can come out of it.”

If it has horses and swords in it, it’s a fantasy, unless it also has a rocketship in it, in which case it becomes science fiction. The only thing that’ll turn a story with a rocketship in it back into fantasy is the Holy Grail.

In fact, one good working definition of science fiction may be the literature which, growing with science and technology, evaluates it and relates it meaningfully to the rest of human existence.

All responsible writers, to some degree, have become involuntary criers of doom, because doom is in the wind; but science fiction writers more so, since science fiction has always been a protest medium.

The main thing about aliens is that they are alien. They feel no responsibility for fulfilling any of your expectations.