While Sagan communicated this bedrock scientific principle throughout his work, I want to draw special attention to how he dealt with religion and superstition.
On nearly every topic, Sagan was very measured and very careful. And while he was certainly not as confrontational as some atheists, those who would use him as a talisman against Gnu Atheist methods should make no mistake: Sagan didn't shy away from criticizing religion when its flaws impact science. Before turning this over to Carl Sagan, I implore his successors (like Neil deGrasse Tyson, who will be featured in the remake of Cosmos) to take Sagan's arguments seriously and heed his exhortation to pursue questions courageously, even if it may make some people uncomfortable. Without further ado, Carl Sagan:
The following excerpts are from Cosmos Episode 7: The Backbone of Night and Episode 10: The Edge of Forever.