In the BBC documentary, The Time of Their Lives, 102 year-old Rose Hacker says (initially talking about the Iraq war):
… I mean the awful thing is that we pretend we know. We know best so you do what I believe in, otherwise I’ll kill you. What sort of life … I mean really clever people are saying that, believing it, I don’t know how they can. See, Keats wrote you have to live in the … negative capability. That means to be able to say, ‘I don’t know, and I never will know.’ There are mysteries, there are wonders, there are beauties, all kinds of things … how can we with our silly little ant brains understand? I mean, everything’s a mystery isn’t it, and love is the biggest mystery of all.
Here’s the wikipedia entry on negative capability.