People mostly "buy into" ideas they already have: developing critical thinking requires access to all sorts of true and false material, so readers would learn to differentiate between their nuances.

If the only book in your library is Mein Kampf, you are likely to empathise with young Mr. Hitler. If you have access to alternative viewpoints, you'll be forced to compare and contrast, and you just might develop your own understanding of the world.

But note that you'll always be comparing to the actual circumstances in your proximity: at school, neighbourhood, work...