An international leader in bioethics, Peggy [Battin] explored the right to a good and easeful death by their own hand, if need be, for people who were terminally ill, as well as for those whose lives had become intolerable because of chronic illness, serious injury or extreme old age. She didn’t shy away from contentious words like “euthanasia.” In the weeks after the accident, Peggy found herself thinking about the title character in Tolstoy’s “Death of Ivan Ilyich,” who wondered, “What if my whole life has been wrong?” Her whole life had involved writing “wheelbarrows full” of books and articles championing self-determination in dying. And now here was her husband, a plugged-in mannequin in the I.C.U., the very embodiment of a right-to-die case study.