Stephen Hawking on death, disability, and humour
17 September 2013 Last updated at 11:50 BST
A documentary about the life of Professor Stephen Hawking is to be released in cinemas.
When Professor Hawking was diagnosed with Motor Neurone disease aged 21, doctors gave him just three years to live.
In an interview with the BBC to mark the film's release Professor Hawking discussed his disability and gave his views on controversial issues such as the right to die.
"I think those who have a terminal illness and are in great pain should have the right to choose to end their lives, and those who help them should be free from prosecution", said Professor Hawking.
Tim Muffett went to meet him