Abstrak: For more than 40 years, the tobacco industry prevailed in lawsuits brought by injured smokers, despite overwhelming epidemiological evidence that smoking caused lung cancer. Tobacco lawyers were able to create doubt about causation. They sought to persuade jurors that "everybody knew" smoking was harmful but "nobody knows" what causes cancer by recreating in court the scientific debate resolved by the 1964 Surgeon General's Report. The particularistic structure of jury trials combined with the law's mechanistic view of causation enables a defendant to contest virtually any claim concerning disease causation. Despite judicial efforts to eliminate "junk science" from lawsuits, a well-financed defendant may succeed in persuading jurors of the epidemiological equivalent of the proposition that the earth is flat.