Stephen Hawking, the British theoretical physicist who suffers from motor neurone disease, has publicly backed the notion of assisted suicide for people with terminal illnesses.
"We don't let animals suffer, so why humans?" the 71-year-old said in a BBC interview, although he insisted there should be safeguards.
Hawking is regarded as one of the world's most brilliant living scientists, who shot to popular fame with his 1988 international bestseller "A Brief History of Time".
He is also known for his disability, having spent most of his life in a wheelchair and speaking through a machine.
Hawking suffers from amyotrophic lateral sclerosis (ALS), a form of motor neurone disease that attacks the nerves controlling voluntary movement.
After suffering from pneumonia, he was once put on a life support machine which his wife was given the option of switching off.
Asked about the idea of assisted suicide, Hawking said: "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 that help them should be free from prosecution.
"We don't let animals suffer, so why humans?"
"There must be safeguards that the person concerned genuinely wants to end their life and they are not being pressurised into it or have it done without their knowledge or consent, as would have been the case with me."
He was speaking in an interview aired Tuesday ahead of the premiere of a new film about his life on Thursday, and after the release of a new book last week entitled "My Brief History".