It's not obvious that knowing more always makes us better off — because the landscape of rationality is not smooth.

The quote in Eliezer's site stating that "That which can be destroyed by the truth should be." sounded to me too strong a claim from the very first time I read it. Many people cultivate falsehoods or use blinkers that are absolutely necessary to the preservation of their sanity (sic), and removing them could terribly jeopardize their adaptability to the environment. It could literally kill them.