Mr. Goodall lived alone in his later years, though he has children and several grandchildren. Most of his friends have died, he says. But he did his own shopping, read Shakespeare and presented poetry to a group of friends.
Until 2016, he worked as an honorary research associate at the Center for Ecosystem Management at Edith Cowan University in Perth, taking two buses and a train to get to his office four days a week.
When he was 102 and called Australia’s oldest scientist, the university stirred up a tempest by asking Mr. Goodall to vacate his office on the grounds that he was too frail and a safety risk to himself. He challenged the decision, but he moved closer to home to continue working.
But his world became smaller, as he was forced to give up driving and performing in the theater, Carol O’Neill, a friend and a representative of Exit International, told the BBC.
“It was just the beginning of the end,” she said.
Then, last month, he fell in his one-bedroom apartment and was not found for two days. Doctors ordered him not to use public transport or even to cross the road by himself. His physical condition deteriorated.
His daughter, Karen Goodall-Smith, said that his work had probably been keeping him alive, according to Exit. “His work is his hobby, as well as his passion,” she said, “and without his work, I don’t think that there would be a purpose for him any more.”
Ms. Goodall-Smith added: “He has no control over his life, over his body, over his eyesight. He has lived a really good 104 years. Whatever happens, whatever choices are made, they’re up to him.”
Mr. Goodall is adamant. “One should be free to use the rest of one’s life as one chooses,” he has said. “If one chooses to kill oneself, then that’s fair enough. I don’t think anyone else should interfere.”