The euthanasia debate raises serious questions for dying patients and their families, as well as for ethicists and lawmakers. But many of the right-to-die movement’s leaders, and many of its most outspoken opponents, are physicians.

“What is really at stake here is physician-assisted suicide,” state authors Leon Kass and Nelson Lund, who are opposed to the practice. As Hemlock Society executive director Faye Girsh explains, “It is necessary for physicians to be the agents of death if the person wants to die quickly, safely, peacefully and non-violently, since the best means to accomplish this is medication that only doctors can prescribe.”

Yet even ardent supporters of physician-assisted suicide are aware that many doctors object to the practice. Gerald Larue, in his book Playing God: Fifty Religions' Views on Your Right to Die, argues that dying...