and one of my favourites:
Things are not what they appear to be: nor are they otherwise.
Surangama Sutra
and one from part of the previous Brains Trust in the US:
"Reports that say something hasn't happened are always interesting to me, because as we know, there are known knowns; there are things we know we know, we also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns -- the ones we don't know we don't know."
Donald Rumsfeld

