For the foreseeable future, the rapid influx of information from sequencing the human genome will raise to a still higher level the complexity of scientific and ethical issues confronting the practice of medicine. Sustained attention to the nature and quality of medical evidence and the extent of medical uncertainty is thus important for all concerned--health care providers, policy makers, the media, and the general public. The situation poses a special challenge for educators. This article presents the author's Ethics of Evidence, an approach for dealing with the uncertainties of medicine in the full context of contemporary culture. Meant to be of service to all of society, the Ethics of Evidence can be symbolized by a lighthouse--a beacon to warn of danger and to show the way. It is illustrated here by the example of hypertension, a medical condition afflicting tens of millions of Americans.