Except in pure mathematics, nothing is known for certain (although much is certainly false). — Carl Sagan Copy Share Image
Preserve and cherish the pale blue dot, the only home we've ever known. — Carl Sagan Copy Share Image
GO WHERE YOU'VE NEVER BEEN. Somewhere, something incredible is waiting to be known. — Carl Sagan Copy Share Image
When permitted to listen to alternative opinions and engage in substantive debate, people have been known to change their minds. It can… — Carl Sagan Copy Share Image
There is a lurking fear that some things are not “meant" to be known, that some inquiries are too dangerous for human… — Carl Sagan Copy Share Image
“The Apollo pictures of the whole Earth conveyed to multitudes something well known to astronomers: On the scale of the worlds -… — Carl Sagan Copy Share Image
If you look at Earth from space you see a dot, that's here. That's home. That's us. It underscores the responsibility to… — Carl Sagan Copy Share Image
That we can now think of no mechanism for astrology is relevant but unconvincing. No mechanism was known, for example, for continental… — Carl Sagan Copy Share Image
For myself, I like a universe that, includes much that is unknown and, at the same time, much that is knowable. A… — Carl Sagan Copy Share Image
It is sometimes said that scientists are unromantic, that their passion to figure out robs the world of beauty and mystery. But is it… — Carl Sagan Copy Share
The prediction of nuclear winter is drawn not, of course, from any direct experience with the consequences of global nuclear war, but rather from… — Carl Sagan Copy Share
The suppression of uncomfortable ideas may be common in religion or in politics, but it is not the path to knowledge; it has no… — Carl Sagan Copy Share
“Telepathy’ literally means to feel at a distance, just as ‘telephone’ is to hear at a distance and ‘television’ is to see at a… — Carl Sagan Copy Share
“On the scale of worlds—to say nothing of stars or galaxies—humans are inconsequential, a thin film of life on an obscure and solitary lump… — Carl Sagan Copy Share
Every one of us is, in the cosmic perspective, precious. If a human disagrees with you, let him live. In a hundred billion galaxies,… — Carl Sagan Copy Share
In our time, we have sifted the sands of Mars, we have established a presence there, we have fulfilled a century of dreams! — Carl Sagan Copy Share
“[ When a religious couple wrote to Sagan about fulfilled prophecies, he wrote back in May 1996 :] If ‘fulfilled prophecy’ is your criterion,… — Carl Sagan Copy Share
“Books permit us to voyage through time, to tap the wisdom of our ancestors. The library connects us with the insight and knowledge, painfully… — Carl Sagan Copy Share
We live on a hunk of rock and metal that circles a humdrum star that is one of 400 billion other stars that make… — Carl Sagan Copy Share
A tiny blue dot set in a sunbeam. Here it is. That's where we live. That's home. We humans are one species and this… — Carl Sagan Copy Share
Any sufficiently crisp question can be answered by a single binary digit-0 or 1, yes or no. — Carl Sagan Copy Share
Humans — who enslave, castrate, experiment on, and fillet other animals — have had an understandable penchant for pretending animals do not feel pain.… — Carl Sagan Copy Share
