I do not use airplanes. They strike me as unsporting. You can have an automobile accident-and survive. You can be on a sinking ship-and survive. You can be in an earthquake, fire, volcanic eruption, tornado, what you will-and survive. But if your plane crashes, you do not survive. And I say the heck with it.

Today's science fiction is tomorrow's science fact.

Fifty years," I hackneyed, "is a long time." "Not when you're looking back at them," she said. "You wonder how they vanished so quickly.

Science can be introduced to children well or poorly. If poorly, children can be turned away from science; they can develop a lifelong antipathy; they will be in a far worse condition than if they had never been introduced to science at all.

Although the time of death is approaching me, I am not afraid of dying and going to Hell or (what would be considerably worse) going to the popularized version of Heaven. I expect death to be nothingness and, for removing me from all possible fears of death, I am thankful to atheism.

John Dalton's records, carefully preserved for a century, were destroyed during the World War II bombing of Manchester. It is not only the living who are killed in war.

A robot must obey the orders given it by human beings except where such orders would conflict with the First Law. [The Second Law of Robotics]