“Once you give a charlatan power over you, you almost never get it back.”

— Carl Sagan, The Demon-Haunted World, 1995, Ch. 13

About Carl Sagan

1934 – 1996

American astronomer and science communicator, author and presenter of "Cosmos".

“We make our world significant by the courage of our questions and by the depth of our answers.”

“Books are key to understanding the world and participating in a democratic society.”

“Imagination will often carry us to worlds that never were. But without it we go nowhere.”

“He is a wise man who does not grieve for the things which he has not, but rejoices for those which he has.”

Attribution note: Source disputed or unverified.

“Knowing yourself is the beginning of all wisdom.”

Attribution note: Source disputed or unverified.

“Yesterday I was clever, so I wanted to change the world. Today I am wise, so I am changing myself.”

“He who knows others is wise; he who knows himself is enlightened.”

Attribution note: Source disputed or unverified.

“The man who asks a question is a fool for a minute, the man who does not ask is a fool for life.”

“The truth is rarely pure and never simple.”