A cleareyed Malcolm Gladwell discusses the American penchant for reducing all activity to a moral lesson that can be imparted through the powerful cocktail of stage presence and rear-screen projection. Drawing a line from Benjamin Franklin to the homilies printed on Celestial Seasonings tea boxes, Mr. Gladwell says that even knotty concepts from fields like quantum physics and philology can be made attractive to large groups of people if the concepts are rendered as anecdotes involving a cabdriver, a small child or an obscure Flemish botanist. “Start with a personal anecdote,” Mr. Gladwell suggests, “and then extrapolate to the 18th-century cocoa trade in Malta.”