[N]o scientist likes to be criticized. ... But you don't reply to critics: "Wait a minute, wait a minute; this is a really good idea. I'm very fond of it. It's done you no harm. Please don't attack it." That's not the way it goes. The hard but just rule is that if the ideas don't work, you must throw them away. Don't waste any neurons on what doesn't work. Devote those neurons to new ideas that better explain the data. Valid criticism is doing you a favor.
Carl SaganYou're an interesting species, an interesting mix. You're capable of such beautiful dreams and such horrible nightmares. You feel so lost, so cut off, so alone, only you're not. See, in all our searching, the only thing we've found that makes the emptiness bearable is each other.
Carl SaganYour religion assumes that people are children and need a boogeyman so they'll behave. You want people to believe in God so they'll obey the law. That's the only means that occurs to you: a strict secular police force, and the threat of punishment by an all-seeing God for whatever the police overlook. You sell human beings short.
Carl SaganThe nuclear arms race is like two sworn enemies standing waist deep in gasoline, one with three matches, the other with five.
Carl Sagan