Book excerpt: In Untruth, Newsweek and Washington Post columnist Robert J. Samuelson explains why our political, economic and cultural debates so routinely traffic in misinformation--popular fads that, like meteors, momentarily burn brightly in public consciousness and then fizzle out. Advocacy groups, politicians and their unwitting allies in the media instinctively create agendas of problems that afflict society and must be "solved".The problems are often exaggerated and oversimplified, and the result is that the public is misled about what is wrong and how easily it can be made right. Untruth is the first collection of Samuelson's insightful assaults on the conventional wisdom. Included are columns arguing that campaign contributions have not corrupted politics, that the "service economy" is not turning America into a nation of hamburger flippers, and that the Internet isn't the most important invention since the printing press.