As I've tried to stress, at the heart of science is an essential balance between two seemingly contradictory attitudes - an openness to new ideas, no matter how bizarre or counterintuitive, and the most ruthlessly sceptical scrutiny of all ideas, old and new. This is how deep truths are winnowed from deep nonsense. The collective enterprise of creative thinking and sceptical thinking, working together, keeps the field on track. Those two seemingly contradictory attitudes are, though, in some tension.

— The Demon-Haunted World by Carl Sagan, Ann Druyan (Page 295)