Q. How does Judaism define the moment of death?
A. Before summarising the rulings of the authorities let me recall the day when I sat by the bedside of a certain patient whose life was ebbing away. For just a moment my attention was distracted. When I looked back, she had become perfectly still. I called the nursing staff and they carried out the checks they were trained to perform. As far as I was concerned, this was an example of a person becoming inanimate without bodily movement, respiration and heartbeat.
Historically, rabbinic authorities used absence of spontaneous respiration and heartbeat as signs of death. In more recent years Rabbi Moshe David Tendler and others have advocated a definition based on brain stem death even if there is some cardiac activity. The situation is complicated by the ability of medical technology to maintain a degree of artificial functioning after brain stem death. This artificial functioning is called “life support” though it is questionable whether it is life that it is supporting. The Israeli Chief Rabbinate accepts the concept of brain stem death.
This ruling follows the view of halachic decisors such as the late Chief Rabbis Avraham Shapira and Mordechai Eliyahu. However, there are great halachists who maintain the traditional definition stated above. The subject has become topical in the light of a recent case in Israel.