The speeches given to new graduates at American universities are a distinct literary form – and a measure of national moodTo understand what is going on in America’s head, it is worth tuning in to the early summer hum of commencement addresses. These secular sermons, delivered by politicians, businesspeople, entertainers and other assorted worthies to those graduating from university, are a unique literary form which provides an excellent measure of the national mood. They offer the latest riffs on America’s great national themes, on ambition, equality, perseverance and optimism. In good times, they are giddy; in bad times, sober. In the muddled middle, where we find ourselves now, they are as confused as the various market indicators — one day as glum as Harold Camping, the Californian preacher who predicted the world would end this past May, the next as high as an early-stage investor in Facebook.