It falls to Michael Moore’s empty stomach to help explain to me the difference between hope and optimism. “Right now, I’m hoping that somebody will feed me today,” he says. But that hope is passive. It may whet his appetite, but the disappointment will be all the more crushing if it isn’t satisfied. On the other hand, he explains, optimism is constructive, strategic. “I’m in a first world country, and somewhere I have a wallet with a credit card and some money in it. So the optimist in me has credibility, because it’s safe to say I will eat. Does...