In June of 1989 The Johns Hopkins Medical School celebrated its hun­ dredth anniversary. In the half-dozen speeches at the opening ceremonies, given by major figures at Hopkins, plus the Secretary of Health, the Postmaster General, and the chief executive officer of one of the country's leading pharmaceutical houses, all the important problems confront­ ing modern medicine were addressed, from AIDS to our legal system­ with one exception. Not one speaker mentioned the animal activists. After the convocation I asked my host, one of the world's leading neurophysiologists, how he could account for this. His answer: "David, they're scared to death." On February 8, 1990, the Dean of the Knoxville Tennessee School of Veterinary Medicine was murdered. He was found in the driveway of his home with eight bullets in his chest. Less than two weeks later the Boston Herald reported that animal-rights extremists had threatened to kill one veterinary-college dean each month for twelve months, as a protest against research involving the use of animals. At present these rumors remain unconfirmed, and there seems to be no shred of evidence that the murder had anything to do with the animal activists. What is significant is the immediate and instinctive reaction of those of us who use animals in our research, to have it even cross our minds that the murder might represent some new wave of fanaticism on the part of the animal-rights activists. No one who uses animals in medical research can doubt that these activists pose a most serious threat to our field and to society. I am not a scholar of the animal-activist movement and do not count myself an expert in its history or philosophy. My involvement comes partly from the fact