JOHANNESBURG — Sean Davison's mother, a doctor, knew she faced an impending, painful death from cancer. Not willing to endure it, she chose to end her life by not eating. That attempt, Davison said, went terribly wrong.

"It went on for five weeks drinking a glass of water each day," said Davison, a South African citizen by way of New Zealand. "She was decomposing. She couldn't move any limb of her body, which is when I helped her, at her request, to end her life."

End-of-life decisions have become a burning topic of discussion in South Africa, where former President Nelson Mandela has been hospitalized for five weeks, much of that time in critical condition.

A court filing late last month stated that Mandela was in a "permanent vegetative state" but that appears to have been either exaggerated or simply incorrect.

A report from the Mail and Guardian, a respected South African newspaper, said that the 94-year-old does not have a living will, meaning tricky end-of-life decisions could be left to a very fractured Mandela family.

Mandela's wife — his third — said Friday she is "less anxious" about the health of South Africa's first black president than she was a week ago. "He continues to respond positively to treatment," said Graca Machel.

Friends and family who have visited Mandela say he is responsive and they feel he is communicative through facial and eye movements. But he being assisted by mechanical breathing, medical support he may require for the rest of his life. That means delicate decisions may still have to be made.

Ahmed Kathrada, a close friend of Mandela's and a fellow anti-apartheid leader, said after a recent hospital visit that Mandela is a "shell" of his former self.

The legalities of end-of-life decisions — including terminal pain management and the withholding of life-saving treatment — are murky in South Africa, said Willem Landman, the executive director of the Ethics Institute of South Africa, who wrote in a 2012 paper that the law requires greater clarity.

"Ultimately, at issue here is the suffering of people in the end stage of life," Landman wrote. His paper argued that South Africa should decriminalize assisted dying for the terminally ill and asks whether creating such a law is consistent with or even required by South Africa's constitution.

South Africa's National Health Act of 2003 says that health services may not be provided to a patient without that person's informed consent unless the patient is unable to do so. If no person has been appointed, then consent can be granted in Mandela's case by a spouse or an adult child, in that order.

Mandela when president commissioned a government report and draft bill on assisted dying in 1998, said Davison, who is also founder of DignitySA, a group working to pass a law giving the right to terminally ill people to end their own lives. The bill was presented to parliament, but the legal body took no action.

"I would speculate that he believed in the concept or that he believed the concept should be debated," Davison said.

"It's a taboo subject for many. Homosexuality, abortions, AIDS, drug abuse — these subjects are no longer taboo. They are dinner table discussions, and hopefully death and dying will equally be discussed around the dinner table one day," he said.

Helena Dolny, a banking executive, watched her husband, Joe Slovo, one of Mandela's Cabinet ministers and a leading member of Mandela's party, the African National Congress, die a slow death from cancer. Dolny is writing a three-part series in the Johannesburg paper City Press called "Let's talk about dying." She wrote that Mandela is giving South Africa a "precious parting gift" by spurring a conversation about death.

"I think this is one of the most awful times any family has to bear — watching the slow ebbing away of life from the person you love so much," she said.

Davison's mother was 85 and terminally ill when Davison helped her die. He was arrested, charged and eventually pleaded guilty to a charge of assisted suicide. He was sentenced to five months of house arrest in New Zealand. His wife and two children remained in South Africa.

DignitySA, which is attracting audiences of hundreds of people to end-of-life discussions, is recruiting high-profile patrons and has a three-year strategy to persuade a member of parliament to table a bill and open it to public debate. Davison said he's heard from many families where elderly grandparents or parents are on life support but nothing was ever put in writing about their wishes in the situation.

"You and I probably think the same thing and we think we'll put it in writing one day, but we don't," Davison said, who referred to Mandela by his clan name, Madiba. "(Former Israeli Prime Minister) Ariel Sharon has been on life support for seven or eight years and we've kind of forgotten about him ... Theoretically Madiba could be on life support for a very long time."