“He would get up and go out into a world which seemed very unfamiliar, but with a tantalizing unfamiliarity like the world of boyhood to which an old man returns.”

“What seems natural to us is probably just something familiar in a long tradition that has forgotten the unfamiliar source from which it arose. And yet this unfamiliar source once struck man as strange and caused him to think and to wonder.”

“...nothing in the world is harder than convincing someone of an unfamiliar truth.”

“An indescribable oppression, which seemed to generate in some unfamiliar part of her consciousness, filled her whole being with a vague anguish. It was like a shadow, like a mist passing across her soul's summer day. It was strange and unfamiliar; it was a mood. She did not sit there inwardly upbraiding her husband, lamenting at Fate, which had directed her footsteps to the path which they had taken. She was just having a good cry all to herself.”

“Do you see that out there? The strange, unfamiliar light? It's called the sun. Let's go get us a little.”

“By and large, the kind of science fiction which makes tomorrow's headlines as near as this morning's coffee has enlarged popular awareness of the modern, miraculous world of science we live in. It has helped generations of young people feel at age with a changing world.But fashions change, old loves return, and now that Sputniks clutter up the sky with new and unfamiliar moons, the readers of science fiction are willing to wait to read tomorrow's headlines. Once again, I think, there is a place, a wish, a need for the wonder and color of the world way out. The world beyond the stars. The world we won't live to see. That is why I wrote The Door Through Space.”