When you finally understand the universe, it will not only be stranger than you imagine, it will be stranger than you can imagine.

He was moving through a new order of creation, of which few men had ever dreamed. Beyond the realms of sea and land and air and space lay the realms of fire, which he alone had been privileged to glimpse. It was too much to expect that he would also understand.

Using material ferried up by rockets, it would be possible to construct a "space station" in ... orbit. The station could be provided with living quarters, laboratories and everything needed for the comfort of its crew, who would be relieved and provisioned by a regular rocket service. (1945)

. . . the newspapers of Utopia, he had long ago decided, would be terribly dull.

Only feeble minds are paralyzed by facts.

Religion is a by-product of fear. For much of human history it may have been a necessary evil, but why was it more evil than necessary? Isn’t killing people in the name of god a pretty good definition of insanity?

Science fiction seldom attempts to predict the future. More often than not, it tries to prevent the future.