Carl Sagan

"The beauty of a living thing is not the atoms that go into it, but the way those atoms are put together."

"We are a very young species, struggling to understand ourselves and the universe."

"The persistence of life is the most remarkable phenomenon in the universe."

"There is a range of vibrations and melodies we cannot perceive, yet they exist."

"Evidence is the basis for all rational thought."

"A key strategy in pursuing truth is remaining humble about what we don't know."

"The past can be understood only insofar as we understand the present."

"What an astonishing thing a book is—it's a flat object made from a tree with flexible parts on which are imprinted lots of funny dark squiggles."

"Science demands evidence and critical thinking; it is the foundation of knowledge."

"The universe is not only queerer than we suppose, but queerer than we can suppose."

"Understanding deeply means approaching things with both rigor and reverence."

"We are made of material that is billions of years old."

"The human capacity for self-deception is remarkable and dangerous."

"In every age there have been profound insights and also profound delusions."

"Civilizations require transmission of knowledge across generations to survive."

"The night sky connects us to our ancestors and to future generations."

"Careful thinking is the greatest gift we can offer."

"Wonder is the root of all science and learning."

"The Earth is a small stage in a vast cosmic arena."

"We owe it to ourselves to understand the world we inhabit."

"Art and science both involve creative expression and careful observation."

"Humans are capable of both great compassion and great cruelty."

"Our responsibility is to do better with each generation."

"The pursuit of knowledge is the noblest human endeavor."

"There is something profound about recognizing our connection to all life."

"Dogmatism and critical thinking are incompatible."

"The universe is vast, but we are not insignificant within it."

"Understanding requires both evidence and imagination working together."

"We have the capacity to know so much more than we do."

"Science fiction can help us imagine better futures."