No one has a crystal ball these days — certainly not Obama, as he keeps telling us. But his optimism and faith in the American character may be our best medicine. Asked what the American people should do — shop? — he urged confidence that “the same productive capacity that we had before is still there.” Describing government and the economy as ocean liners, not speedboats, he said our goals are long-term. Nothing can be judged by a one-day market rise or fall. At the end of his first presidential term, Americans will be able to say that we are in a different place.