My old English buddy, John Rackham, wrote and told me what made science fiction different from all other kinds of literature - science fiction is written according to the science fiction method.

That's what life is, just one learning experience after another, and when you're through with all the learning experiences you graduate and what you get for a diploma is, you die.

I was thinking of writing a little foreword saying that history is, after all, based on people's recollections, which change with time.

You don't think progress goes in a straight line, do you? Do you recognize that it is an ascending, accelerating, maybe even exponential curve? It takes hell's own time to get started, but when it goes it goes like a bomb.

If you don't care about science enough to be interested in it on its own, you shouldn't try to write hard science fiction. You can write like Ray Bradbury and Harlan Ellison as much as you want.

You can't really predict the future. All you can do is invent it.

I did that for 40 years or more. I never had any writer's block. I got up in the morning, sat down at the typewriter - now, computer - lit up a cigarette.