As the first paper in this Journal Conference on intensive care unit controversies, the editors wished us to set the tone for the debate by discussing the ethics of medical "adventurism" in the intensive care unit. More life-or-death decisions are made in the intensive care unit than elsewhere in the hospital, and the critical care specialist often sees himself or herself as a warrior in a battle with death. This adrenaline-charged calling attracts highly intelligent, hard-working, and compassionate caregivers, as well as fiercely independent clinicians. The result of this is that critical care specialists passionately debate about the meaning and application of published "evidence" and this leads to thoughtful debate, as exemplified by the papers in this and the next issue of Respiratory Care, as well as thoughtless and often dangerous disregard for evidence-based medicine. Physicians are morally obligated to provide the best and most appropriate care possible for their patients, but when accepted approaches are failing and a critically ill patient is getting worse, the critical care physician must make a decision regarding innovative therapy, based on the patient's prognosis, the available evidence, the resources on hand, the expertise of the physicians, and the values of the patient and the physician. This decision may lead, at times, to trying unproven and innovative strategies to achieve a clinical goal. In such cases, it is to be hoped that this can be done in such a way that data are formally and prospectively collected to increase our knowledge.