Is there a right to die?
Tony Nicklinson scans the screen, blinks, and then his words - which he has painstakingly compiled - are read out by a computer-generated voice.
Mr Nicklinson can do almost nothing for himself - nothing except make a few eye and head movements. But it is enough for him to make his views crystal clear.
Although he was paralysed by a stroke in 2005, his intellect is intact. I met him and his wife Jane at their home in Wiltshire in advance of his High Court hearing.
Mr Nicklinson wants the courts to allow a doctor to give him to give him a lethal dose - it is a direct challenge to the law on murder.
It takes Mr Nicklinson a minute or two to compose each sentence. A sensor at the bottom of the screen tracks his eye movements and when he settles on the letter or word he wants, he blinks. I interviewed him at his home in Wiltshire a few days ago.
His care needs are too complex to allow him to make the journey to court.
I have reported his case several times so I was glad to meet him and to try to understand a little more about his life and why he wants to be allowed to die.
He told me "each day is getting that little bit more uncomfortable and harder to bear".
You can watch the interview by clicking the box above.Euthanasia
The hearing at the High Court represents a fundamental challenge to the law on murder. In amounts to an appeal to allow euthanasia which is strictly prohibited.
It goes further than the case of Diane Pretty, who had motor neurone disease. The House of Lords rejected her appeal in 2001 to allow her husband to assist her suicide.
Tony Nicklinson is paralysed from the neck down so he could not pick up and drink a lethal cocktail prepared by another. Instead he wants a doctor to administer the lethal dose.Common law
So what are the arguments which Tony Nicklinson's legal team will use in court?
First they will try the common law defence of necessity against a murder charge - arguing that the only way to end his suffering is to allow him to die. This is judge-made and judge-interpreted law - it's not written down in statute.
Necessity was used successfully in 2000 in the case of conjoined twins - doctors had to separate them in order to allow one to live. They knew the other twin would die, but necessity demanded they sacrifice one to save the other, otherwise both would have perished.
This case is very different, and I have re-read the judgement in the Pretty case at the House of Lords, and there the same argument of necessity was rejected.
Mr Nicklinson's team will also argue that his case is covered by Article 8 of the European Convention on Human Rights which deals with the right to respect for private and family life.
This does not mention a right to death, but this part of the Convention has been frequently used in assisted suicide cases.
Mr Nicklinson will not be at court as his care needs are too complex to allow him to journey from Wiltshire to London.
The hearing at the High Court will last a few days and then judgement is expected to be reserved until a later date.
The case raises huge ethical and social issues which will spark major debate in the weeks ahead. Win or lose, Mr Nicklinson can be assured that the issue of whether there is a right to die will be discussed in great detail by judges, politicians, the media and the public.