Is performance artist David Blaine for real - or is his act all smoke and mirrors?
The audience at David Blaine's press conference on Monday, at which he apparently sliced his ear with a penknife, kept returning to the same question: Why?
Of course, seeming to mutilating himself with a penknife gets him on the front pages to publicise his forthcoming televised "starvation" challenge.
But there remained the question of what might drive the 30-year-old New Yorker to want to "hurt" himself in front of dozens of strangers.
Of course many people still want to know what would make a man spend 44 nights inside a small transparent box hung over the Thames, supposedly with no nutrition other than water.
Is it purely to service a giant ego, or is there real craft to Blaine's seemingly self-serving - some would say, pointless - posturing?
Blaine has insisted his acts are all about self-exploration and art, and little to do with money - although his fee for the Channel 4/Sky TV collaboration remains a secret.
"I'm an artist - nothing more, nothing less," he said. "I don't fear life and I don't fear death."
But his critics say he is deluding not only the public, but himself.
British magician Paul Zenon told BBC Radio 5 Live: "He says there's no trickery involved - I think there's a clue in the fact that he's a magician. That's what we do - we tell lies."
There is also the matter of taste. He reportedly has the number of a concentration camp victim tattooed on his arm - and said he had prepared for his upcoming fast after reading up on Auschwitz survivor Primo Levi and IRA hunger striker Bobby Sands.
Dismissing fears of his demise during the upcoming stunt, Blaine told the press conference of watching his mother "die a very peaceful death", an experience he described as "beautiful".
Critics are concerned that he is willing to discuss his work in the context of the horrors of the gas chamber.
"I find the whole thing slightly distasteful," Mr Zenon said.
"The whole idea that no-one has spent 44 days on their own with only a liquid diet - there are plenty of people in hospital isolation units who are there through no fault of their own.
"If he was doing it to highlight the plight of political prisoners in Burma... but it's purely an exercise in self-aggrandisement."
In person, Blaine displays an enigmatic, almost inscrutable, quality.
There is a neutrality about his body language, and a lack of expression bordering on the dour, that gives away as few clues to his motivation as his studied soundbites.
Perhaps the closest we get to the real Blaine is his declaration that he wants to be remembered as "the greatest showman of all time".
Some say he sees himself as part of the US tradition of "carnies and hucksters" stretching back to the days of PT Barnum and the covered-wagon medicine shows.
He has been likened to Harry Houdini, though his detractors say he does not bear comparison with the mythical American escapologist.
"Houdini used to do things," said Mr Zenon, dismissing Blaine's starvation challenge as "pretentious".
There is little doubting his fearlessness, as evidenced when he stepped out on top of a pod on the London Eye last week - foot straps or not.
His past stunts have included standing on a 100ft high pole in New York for 35 hours and encasing himself in six tons of ice for three days.
If the reaction to him at Monday's press conference was anything to go by, he elicits extreme responses - from fascination to revulsion to just plain boredom.
His supposed slashed ear was dismissed by one tabloid as a plasticine-and-ketchup trick.
There are suggestions he could fall on the same illusory skills to feed himself during his six-week spell in the box.
On the surface Blaine maintains an air of general disinterest in the public's reactions.
He said: "Some will like it, some will hate it, some will be cynical, some will understand. Some will think it will be plain lunacy.
"I don't really want to be understood."