Cigarettes are among the most addictive substances of abuse and by far the most deadly. In this country smokers know it and try to stop. Their success has been dramatic but partial and excruciatingly slow, and until recently quite uncoerced by government. Cigarettes and nicotine have characteristics distinct among addictive drugs, and some of these help explain why efforts to quit smoking are so often frustrated. Nicotine itself is the most interesting chemical in the treatment of addiction and, in some forms, can pose a dilemma: compromise by settling for pure nicotine indefinitely, or stay with cigarettes and keep trying to quit. Nicotine is not alone among addictive drugs in becoming increasingly identified with the poorer classes. This article, reprinted from Science, looks at smoking behavior along with the social trend towards quitting, characteristics of cigarettes and the cigarette industry, and nicotine addiction. It observes that the motivation for quitting is probably strongest among people who are in a condition to appreciate longevity and are best positioned to receive and understand health messages from credible sources. Except for those lowest in socioeconomic status, motivating people to quit is no longer the problem. The problem is relapse, which can be coped with in one of two ways: (1) avoidance of relapse and (2) recovery from relapse.