On Friday the House of Lords will debate legislation which would, if passed, make assisted dying legal in the UK.

The argument over assisted dying and its bedfellow, euthanasia, is not a new one.

For centuries, philosophers, ethicists and theologians have debated whether an individuals has the fundamental ‘right’ to commit suicide.  The idea of legally empowering another party to assist in the process, to actually inject a chemical that ends one’s life, is an extension of that debate.

In our time the issue has scaled the walls of cloistered academia, to become very much a real world problem – or opportunity, depending on your point of view. This is partly because advances in medicine and medical technologies have made longer life a reality for most people in the developed world.

Not only are we able to live longer, however. We are also around long enough to face as yet unconquered illnesses of mind and body. Debilitation possibly seems more offensive to us today, too, because we place great faith in technology and pharmaceuticals and their capacity to deliver quality of life to the end.

On a philosophical level, the general rapid advances we see in technology encourage the idea that human beings can and should be the sole deciders of their individual destinies. It is a line of thought which has arguably, in some ways, placed individual rights above social responsibilities.

In recent years, the debate on the right-to-die has taken on an air of inevitability, at least if some of the press and media are to be believed. We often read of celebrities, politicos and other public figures who are convinced that assisted dying is the most compassionate way forward for some people.

This week, church leaders such as former Archbishop of Canterbury Lord Carey and South African cleric Desmond Tutu have joined those calling for right-to-die laws.

They have done so largely as a result of witnessing firsthand or hearing reports about individual cases in which it appears assisted dying legislation may have alleviated suffering.

A number of prominent British celebrities, among them actor Patrick Stewart, have already announced that they will be seeking an assisted death when, in their own estimation, they are no longer able to function independently or to enjoy a certain quality of life. In these cases, right-to-die is becoming more of a lifestyle choice than a concession to those who suffer.

Compassion must, of course, temper discussions on anything involving human suffering. Yet, while enshrining into law the right to assisted death may sound very tolerant, it is arguably a ticking time bomb, socially and ethically.

Its potential impact on our social structure and the wellbeing of future generations should not be underestimated. Nor should the potential for frail human agencies, be they institutions or individuals, to turn good intention into bad practice.

This is what motivates people like Liz Carr, the UK’s best known disabled actress, to speak against assisted dying legislation. She has urged parliament to throw out the proposed new laws, saying that she doesn’t trust doctors with extra power to prescribe lethal drugs.

Ms Carr, who has been in a wheelchair since childhood, plays a forensic scientist in the BBC’s popular drama Silent Witness. Ms Carr says that if it were not for the dedication of doctors she would not be alive today.

‘But I know they are fallible,’ she adds.  ‘It is very common for someone with a disability to be told they are not likely to live until a certain age – and for them to carry on living.

‘I don’t think doctors are malicious, but there is a prejudice. They wonder how someone they are treating can have any quality of life because they are so dependent on carers or seem to have lost their dignity.

‘They do not think they could cope if it was them. But the person may have adapted very well to their condition to the point of living a good life.’

According to an interview in The Times, Liz Carr also worries about a gradual blurring of boundaries in the public mind between terminal illness and disability.

To be sure, the proposed laws open up unprecedented moral and legal minefields for the future.

First of all, there is the issue of how assisted death, were it to become institutionalised, would be administered. Dignitas is the now famous - or, for some, infamous - privately owned Swiss organisation that provides assisted dying as a ‘service’.

Much has been made of the stories of the few Brits who’ve paid the fees and travelled to the clinic in Switzerland to die. Very little is written, though, about the many thousands who stay at home and receive palliative care, passing away relatively peacefully in the hands of caring family members and professionals.

(When did you last see a TV documentary on aged or sick people who die well, in a hospital or care facility or at home?)

Terry Pratchett, author of the acclaimed Discworld books, has made no secret of his desire to request an assisted death, at a time and in a manner of his choosing. In a BBC documentary broadcast in June 2011, Mr. Pratchett, who suffers from Alzheimer’s disease, said: ‘Is it possible for someone like me, or you, to arrange the death they want? When I can no longer write my books, I’m not sure I will want to go on living.’

In interviews, Mr. Pratchett has admitted that Dignitas sounds like something of a ‘one stop shop’, offering a highly mechanised and impersonal approach to dying. Yet this is the inevitable eventual result of empowering professional practitioners to end a life upon request when care, if not cure, is available.

At present, people across the UK worry – rightly – about the impact of privatising areas of the National Health Service. Their concern is that profit motives may quickly become more important than the burden of care.

Indeed, the privatisation of some aged care facilities has already proven their fears to be valid.

Procedures for patient care have been trimmed to balance the books of private enterprise ‘care providers’. The business side of the equation has overtaken the duty of care. Surrendering care of the feeble to the free market is not always a recipe for efficiency or, more importantly, compassion.

Many moderate supporters of assisted dying will argue that it should only be legalised on the condition that procedures are carried out in government-run, publicly owned facilities, by highly trained and accredited professionals.

Yet the private, profit-seeking sector will always look for ways to engage with the growing edges of new social phenomena. What makes us think that we wouldn’t soon see the emergence of a profit-making industry devoted to ending life, where the business of dying is more important than the duty of care? 

If the current legislation passes, we will likely soon see the emergence of privately-owned, elegantly presented Dignitas-like organisations. They will be run in effect as death clinics, openly advertising their wares. There is, to be sure, a healthy income to be made from trading on the promise of a comfortable death.

They may start by offering a cosy demise only to members of the well-heeled classes. Others would soon follow, offering a scaled back service to the poorer classes.

Though their effect would potentially be far more serious, permanent and, in may cases, damaging to people left behind, these groups would play on the same primal fear of the future that makes payday loan companies so attractive – and eventually so problematic for families and for society.

When interviewed, advocates of assisted dying almost invariably express motivations based on the fear of a worsening physical or mental condition. Let’s be in no doubt about this: it is very often the fear of suffering, not actual suffering itself, that is at the core of the debate about assisted dying.

This is supported by independent studies undertaken in areas where assisted dying and euthanasia have long been on the statute books, including the Netherlands.

According to a study undertaken by a Dutch University a few years ago, only five percent of patients who decided to go through with doctor-assisted suicide listed pain as the biggest factor in their decision. The most prominent factor was the fear of suffering – and 24 percent of the people surveyed said that fear of humiliation was their strongest motivation. (At the time of the study, more than a third of all euthanasia cases in that nation were AIDS related.)

Furthermore, an article published in the Journal of Medical Ethics in 2008 showed that 21 percent of people receiving assisted dying in Dignitas did not have a terminal or progressive illness, but rather felt a ‘weariness of life’.

For these people, the organisation merely offers them a sure-fire way of committing suicide. The possibility exists that in future people may opt for this as a matter of convenience rather than necessity.

These and other studies reveal that it is often emotional trauma, the anticipation of future suffering or debilitation, that drives people to consider assisted dying.  Yet the public debate is often driven by the sense that people only request help to die when they are in unbearable pain.

A very generic law would be absolutely useless in the case of assisted dying. Given the possibilities for abuse and even criminal acts, regulations would need to be iron-clad, leaving little room for interpretation. Yet the law would be dealing in the highly subjective areas of psycho-emotional pain, so it could not possibly hope to be as concise and definitive as proponents of the right-to-die claim.

In the end, we all fear the pain and the loss of control that either severe sickness or old age may bring; but how would those charged with administering and interpreting assisted dying laws decide when it is appropriate for an individual to act on those fears?

Would debilitation be adjudged to occur after six months, a year, two years? When exactly would it be legal for someone to set up a contract to die? And how would new laws define debilitation? What is totally debilitating for one person may be quite manageable for another, especially if they are given the kind of patient care for which many hospitals and hospices have become well known.

The push for assisted dying is undoubtedly most often accompanied by compassionate motives. Yet, good intentions do not necessarily make good public policy.

What we face here is not simply a change in law but a major realignment of our basic cultural values.

The notion of the sanctity of human life is a cultural more that has bestowed great strength on our civilisation. It is one of the core values that has allowed us, thus far at least, to avoid the kind of collapse from within that has marked many earlier societies.

Throughout history, whenever a tolerance for killing has crept into a great civilisation, human values have been undermined and social structures have been mortally weakened. Moreover, societies invariably chip away at their own foundations whenever they move in directions which ensure that the vulnerable become more so.

Supporters of assisted dying will argue that safeguards can be installed to protect the poor, the young and the debilitated. This is naïve; it places far too much faith in systems that are set up and run by fallible human beings.

For all the talk about protective measures, present euthanasia laws in Europe are wide open to abuse. No law is water tight; there are always loopholes and the less than scrupulous are able to twist regulations, especially when they’re loaded, as these laws can only be, with subjective language.

Far from protecting the weak, assisted dying laws will make things harder for many of the more vulnerable people in society. Is there, for example, a bottom age limit for making such a choice? What should that limit be?

In some pro-assisted-death regions, laws allow 12 to 15-year-olds to request euthanasia, as long as they are making a voluntary and well-considered choice, with their parents agreement. We all know how impressionable and vulnerable 12-year-olds can be, which is why we have such tight laws to protect them from pornographers, for example.

So, how can 12-year-olds be expected to make a totally independent and well-considered decision to end their lives – especially when they're seriously ill? And what message are we sending our children, when we tell them that, under certain circumstances, their best hope in life may be death?

Some people will use a ‘quality of life’ argument to defend assisted dying.  For example, if a person can no longer do something they love, which has provided their life with meaning and joy, they should be free to choose to die.

Understandably, people of great distinction in any field will be loathe to lose the facility that has made their name, or through which they have enriched the lives of others. Yet there may well be other ways in which their example can serve not only theirs, but future generations. 

Indeed, the generational impact of right-to-die laws is one of the most powerful arguments against them. What one generation allows but barely tolerates, a new generation may decide to use as its base camp for further assaults on life.

If we allow assisted dying today, will we allow involuntary euthanasia in twenty years from now? This may be unthinkable now, but quality of life arguments similar to those used by assisted dying advocates could be – and have been – made to support it.

Assisted dying, like euthanasia, may seem a merciful option for those who face an uncertain future due to the onset of age-related illness. It may appear the most humane way out for those to whom medical science offers only a limited hope for recovery.

Yet heroic stories emerge all the time, of people young and old who beat the odds – not necessarily by ridding themselves of disease, but by refusing to cower in its shadow. These people refuse to surrender long-held dreams, often doing the most daring things as they approach the end of life.

This unwillingness to go quietly, this commitment to leave a legacy of hope in the face of adversity, is something we celebrate. It is a form of heroism that inspires us all to do more, to live more fully whatever our situation.

We would all wish for a quiet, peaceful and painless death. But trying to ensure this through the introduction of assisted dying is a recipe for social confusion and the breakdown of hope.