I remember reading a quote, I think from the Buddhist or some other Eastern tradition, about how if you've argued yourself into believing the Sun doesn't exist, you've gone horribly wrong. It went something like "Nothing can be known, if even the Sun requires proof". I think I read it either on LessWrong or on gwern.net several years ago, but for the life of me I can't find it. I remember it being phrased more poetically than prosaically.

Does anyone know what quote I'm referring to, and where to find it?