If I was suicidal I hope that people would try to argue me out of it however much pain and anguish I was feeling, however much I wished to end my life then and there, I hope that people would be talking me out of it, letting me know how much they loved me, that my presence on this earth meant something to them. When people who are suicidal post on mn, that's normally the response and quite rightly so.
Imagine now that I am ill and in pain, and say that I want to commit suicide. Does the situation change? How would it be, then, if the people around me, my family, those I love most on earth, say "oh ok then, that's fine"? Are they suddenly to abandon me, to give up the last time we have together on this earth? Should they stop fighting for me to have pain relief and good care from those around me? Should they just abandon me to death? (Giles Fraser used this example in an article in the Guardian this morning)
What this bill proposes isn't a slippery slope, exactly, so much as a quantum leap -- a very small change which nevertheless changes everything. Once you have accepted the principle that killing another person can be right, even in very circumscribed circumstances, you can't argue in principle against it. You have accepted the principle that killing can be right, and then it is almost inevitable that extensions to the law will follow.
So you get to the situation in Belgium where it is now legal for doctors to kill terminally ill children. Although children can't legally consent to sex, they can consent to being killed. That's not just absurd, it's abhorrent.
Many people are in favour of assisted death (or getting a doctor to kill you let's not use a euphemism) because of having watched people in pain. But how much pain is too much? Once we have accepted the principle that the terminally ill could be killed to end their pain, at what point will be next say that death by request is possible? Is our only response to pain even pain that might come to an end -- to say that it must be ended, finally, by death. John Inge's powerful account of his wife's death ( here ) shows what he, and she, and their family would have lost by her having chosen death at the point where she would have been eligible for assisted death under this bill.