"I am now entering my fifth year as a regular heroin user," says Columbia University neuroscientist Carl Hart, the author of Drug Use for Grown-Ups: Chasing Liberty in the Land of Fear. "I am better for my drug use." The 54-year-old father and military veteran makes a powerfully documented case that responsible adults should be free to buy, sell, and use whatever substances they want to and that policy discussions about drug use have been polluted by bad information and moral posturing.