In the ongoing battle over the legalization of marijuana for medicinal purposes, the Food and Drug Administration has now shown that ideology can bend almost anything to its will. Last week, the FDA claimed that "no sound scientific studies" supported the medical use of the drug - flatly contradicting a 1999 review by the Institute of Medicine. That seems strange, given that the Institute is part of the National Academy of Sciences, the nation's most prestigious scientific advisory agency. Could one group of scientists be so far off as to come up with a completely incorrect reading of the medicinal...