An interesting debate is occurring in Great Britain about assisted suicide and right to die laws. Previously, much of the coverage has been about a woman named Debbie Purdy, who suffers from multiple sclerosis and who has led a fight to clarify Britain’s assisted suicide laws. Now, a prominent scientist who, like Ms. Purdy, has multiple sclerosis, weighs in on the opposite side of the debate. His basic message? People should be talking about how to live, not how to die.