Eliezer Yudkowsky said this quote

One of chief pieces of advice I give to aspiring rationalists is Don't try to be clever. And, Listen to those quiet, nagging doubts. If you don't know, you don't know what you don't know, you don't know how much you don't know, and you don't know how much you needed to know.

~ Eliezer Yudkowsky

If you once tell a lie, the truth is ever after your enemy.

~ Eliezer Yudkowsky

And someday when the descendants of humanity have spread from star to star they won’t tell the children about the history of Ancient Earth until they’re old enough to bear it and when they learn they’ll weep to hear that such a thing as Death had ever once existed

~ Eliezer Yudkowsky

It's a most peculiar psychology—this business of 'Science is based on faith too, so there!' Typically this is said by people who claim that faith is a good thing. Then why do they say 'Science is based on faith too!' in that angry-triumphal tone, rather than as a compliment? And a rather dangerous compliment to give, one would think, from their perspective. If science is based on 'faith', then science is of the same kind as religion—directly comparable. If science is a religion, it is the religion that heals the sick and reveals the secrets of the stars. It would make sense to say, 'The priests of science can blatantly, publicly, verifiably walk on the Moon as a faith-based miracle, and your priests' faith can't do the same.' Are you sure you wish to go there, oh faithist? Perhaps, on further reflection, you would prefer to retract this whole business of 'Science is a religion too!

~ Eliezer Yudkowsky