To watch some of the wiser members of a mature democracy grapple with one of the most fundamental issues facing humanity can be a life-affirming experience. That the issue before peers yesterday was, essentially, death, and its treatment in an enlightened, liberal, 21st-century state, underlines the impressive quality of the exercise. There may be some who still maintain that death is an unsuitable, possibly dishonourable and perhaps pernicious, topic for public discussion. The debate surrounding the Assisted Dying for the Terminally Ill Bill has surely laid such fears to rest.

As our letters page has shown in recent days, this is an issue that stirs rare debate, combining deep passions born of horrific experience and cool conviction drawn from first principles. The issue is easily stated — whether to allow the terminally ill but sound of mind to sign away their life in order to avoid the prolonged agonies and indignities of a “natural” death. If it was an easy issue to resolve, there would not have been such engrossing deliberation.

Both sides have used polls to support their case. The public appears to be solidly in favour of allowing assisted suicide, which is certainly significant. Yet we do not, wisely, allow public sentiment to guide us on capital punishment, and nor should it be the final arbiter in this instance. Doctors, by three to one, are against a change in the law, a finding that is also relevant. But this means that a quarter of doctors believe the issue to be of such gravity as to merit a flexible interpretation of the Hippocratic Oath, a conclusion of some significance. Nine out of ten palliative specialists are opposed to the change. Yet many who work with the suffering insist that a failure to change is little short of inhumane.

The safeguards built into the Bill are impressive. The experience of Oregon, on which much of the detail is based, is interesting but not compelling. The argument put forward in the House of Lords yesterday by Baroness Greengross, that allowing the dying a way out of their suffering would give them a sense of security, is reasonable, but does not address the insecurity of those who worry that not only will they be put out to pasture, they might also be put to a premature death.

There are concerns about precedent. The Oregon law remains, essentially, an experiment from which it is too early to draw conclusions. A similar change in the Netherlands looks less convincing. Practical concerns run deeper. Certainly, only willing doctors would administer approved lethal injections. But enabling them to do so would threaten to change fundamentally the doctor-patient relationship.

However well honed the legislation, it is likely to put some well-meaning elderly people under intolerable pressure when they are at their most vulnerable. At what point will “sparing” offspring the emotional trauma and financial expense of an elderly relative’s illness become regarded as “doing the decent thing”?

There are deeper qualms. It is difficult to conceive how a right to death can be enshrined in law without its presence on the statute book having potentially serious implications for the right to life. At a minimum, the Joffe Bill has given eloquent voice to a slice of life that all of us hope we are spared. It has been vacuously argued in the past that human mortality is the final taboo — yesterday’s debate shows that there are many who are rightly fearless in the face of death.