'Right to die' debate on Twitter
The pictures of how Tony Nicklinson used to be present a picture of a big, handsome family man. And then there's another one: of someone else sitting in a wheelchair, evidently incapable of doing anything. If you didn't already know it was the same person, you'd struggle to recognise the transformation.
But that's what a massive stroke does to people, and for the last seven years Tony Nicklinson has described his life as worthless.
He has a rare condition known as "locked-in syndrome", from which there will be no physical recovery. But his mind still works, and it has decided that he wants to die.
The problem is that he can't kill himself - he's physically incapable - and so needs someone else to do it for him. But if his wife or a third party were to then they would, under British law, be guilty of his murder.
So they and the British state are fighting out this existential, impossible, argument in the High Court in London, where some Judges have to decide whether desperate cases like this should be about an individual's freedom to choose his or her fate or whether legal principle opens up a huge can of worms and would be unpoliceable.
But there's something entirely unique about this case outside the "right to die" debate. It's that Tony Nicklinson, who can't do anything except blink, is now on Twitter.
Looking and blinking
Technology has allowed this to happen, and through looking and blinking at a computer Nicklinson can turn his thoughts into words, which he cannot enunciate.
So just a few days ago [and this will probably become a famous remark in the history of social networking], he wrote this: "Hello world. I am Tony Nicklinson, I have locked-in syndrome and this is my first ever tweet."
Among the many fascinating things about this technology is that the very nature of the euthanasia debate means that well-meaning relatives will argue with well-meaning lawyers over a person who cannot speak for him or herself.
Yet now this man can - and not just to the High court, but to the court of public opinion as well. Within five days of his first tweet he had gained 15,000 followers, many of whom were expressing openly supportive opinions of him and his right to die.
Should the law take into account things like this?
Probably not - after all the opinion polls are clear enough already and only demonstrate a huge amount of uncertainty over the right to die.
Opponents of euthanasia are currently arguing that while Mr Nicklinson's case is hugely moving it's also sufficently unusual that it would be dangerous to use it in case law.
But here's the potentially extraordinary thing about Mr Nicklinson and Twitter.
People have begun asking him whether he still thinks his life's worthless if he can enjoy a conversation with anyone in the world on the internet.
Mr Nicklinson's reply suggests an open mind: "People want to know if I will change my mind because of Twitter. Let's hear the judgement first and maybe I'll tell you."
So perhaps if there is something to hang on to in this moral maze it's this: technology has at least the capacity to alter peoples' opinions of themselves, even in desperation: and that things which until recently were scarcely imaginable are now facts of life.
And if Mr Nicklinson's mind were to persuade him that life is still worth living then wouldn't that be a wonderful thing?