“Man’s greatest asset is the unsettled mind.”

No sensible decision can be made any longer without taking into account not only the world as it is, but the world as it will be.

The saddest aspect of life right now is that science gathers knowledge faster than society gathers wisdom.

While he lives, he must think; while he thinks, he must dream.

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

I am not a speed reader. I am a speed understander.

There is no more desire to live past one’s time than to die before it.

If we only obey those rules that we think are just and reasonable, then no rule will stand, for there is no rule that some will not think is unjust and unreasonable.

When asked for advice by beginners. Know your ending, I say, or the river of your story may finally sink into the desert sands and never reach the sea.

The Earth should not be cut up into hundreds of different sections, each inhabited by a self-defined segment of humanity that considers its own welfare and its own “national security” to be paramount above all other consideration.

Properly read, the Bible is the most potent force for atheism ever conceived.

There are no happy endings in history, only crisis points that pass.

The tyranny that now exists is actual. That which may exist in the future is potential. If we are always to draw back from change with the thought that the change may be for the worse, then there is no hope at all of ever escaping injustice.

I wish that I could say I was optimistic about the human race. I love us all, but we are so stupid and shortsighted that I wonder if we can lift our eyes to the world about us long enough not to commit suicide.

At odd and unpredictable times, we cling in fright to the past .

People who think they know everything are a great annoyance to those of us who do.

Intelligence is an accident of evolution, and not necessarily an advantage.