"But more importantly, relying on a single source of information means you can't critically evaluate it. It's like you're locked in a room and every day I come in and tell you what's happening outside. It's very easy for me to make you believe whatever I want. Even if I don't lie, I can just tell you the facts that support me and leave out the one's that don't.

That's what's happening if you're getting all your news from one place. If you stop listening to someone the second you hear a word or a phrase you've been taught belongs to the enemy, like "environment" or "job creators," that's what you're doing. You might be an intelligent person, but once you let someone else filter the world for you, you have no way to critically analyse what you're hearing. At best, absolute best case scenario, if they blatantly contradict themselves, you can spot that. But if they take basic care to maintain an internal logical consistency, which they all do, you've got nothing. You've delegated the ability to make up your mind."

From Lexicon by Max Barry