A Point of View: See No Evil

We'd like to think the financial crisis is safely in the past. The events of 2007-2008, when the world's banking system was on the brink of collapse, seemed like a once-in-a-century upheaval, and it's natural to imagine we've returned to some kind of normalcy. Disaster has been averted, and there may be some signs of recovery in the economy. But have we emerged onto a sunny upland of stability, or are we fooling ourselves? History suggests an upheaval on this scale isn't left behind so easily. Could it be that we know the crisis hasn't been resolved, but prefer not to think about the fact?

Former US secretary of defence Donald Rumsfeld's distinction between known unknowns and unknown unknowns has passed into everyday speech. It's not the things of which we know we're ignorant that we should worry about, he pointed out. It's the things we're unaware of not knowing that can really cause trouble. It's a useful reminder of the vastness of human ignorance. But might there not be another kind of unknown, which Rumsfeld didn't mention - one that consists of things we choose not to know?