Modesty in private life is attractive, but in public life it is essential, especially now, when those who immodestly claimed to Know It All have Wiped Us Out. The problems we face are too fierce to accommodate arrogance. Humility leaves room for complexity, honors honest dissent, welcomes the outlandish idea that sweeps past ideology and feeds invention. We want to reimagine the health-care system, confront climate change, save our kids from a financial avalanche? The odds are much better if we come to the table assuming we don't already have all the answers.