There’s an old saying in the legal profession: “Hard cases make bad law.”

In England right now there’s a particularly hard case that presents the danger of making very bad law indeed. A retired educator named Noel Conway is in the advanced stages of motor neuron deterioration (Amyotrophic Lateral Sclerosis) — what in this country we refer to as Lou Gehrig’s disease.

At age 67, Conway is losing the ability to control all bodily movement as his muscles waste away. At some point, involuntary functions, such as breathing, will break down, as well.

“If I let nature take its course, I could effectively become entombed in my own body, as my ability to move and communicate continues to diminish,” he has explained, “or I may die by suffocation or choking.”

It’s a terrifying prospect, and Conway, quite understandably, wants to avoid it. So he has brought legal action attempting to alter the British law restricting suicide (which has a certain ironic ring after the denial of medical treatment to baby Charlie Gard).

“Having the option of an assisted death would bring me great comfort in my final months,” he insists. “It would empower me to live my life as I choose and to end it with dignity. I believe it is my fundamental human right — one I am willing to fight in the courts to secure.”

I can’t imagine anyone whose heart wouldn’t ache for those in such a situation, or who doesn’t fear the prospect of facing that kind of terror themselves. But in the midst of strong emotions, it’s easy for certain truths to become obscure.

One key truth is that suicide, when committed with full knowledge and deliberate consent, is a mortal sin.

Now, it’s important to remember that only God can judge an individual’s culpability. Some people are mentally ill when they commit this offense. Others have endured such intense and prolonged suffering that they cannot be said to exercise true volition in deciding to end their lives. These judgments we leave to God. Only he knows the heart. We do not speculate on the final disposition of souls.

But there is something in Noel Conway’s statement (made through a British suicide-rights advocacy group) that is revealing. It is his belief in a “fundamental human right” to “live my life as I choose and to end it with dignity.”

This is a sentiment that resonates strongly on our side of the Atlantic. While the Declaration of Independence acknowledges the right to life — not the right to end life — changing public attitudes have made physician-assisted suicide legal in five states (Oregon, Washington, California, Montana and Vermont). Legalization movements are advancing in others.

Many people would agree with Conway’s view, which is based on individual autonomy. This is the libertarian assertion that human beings are self-contained. We are free to do anything with and within our own lives as long as we don’t impinge on the rights, freedom or property of others.

This is the perspective set forth, for instance, in the novels of writer/philosopher Ayn Rand. And it has broad appeal among virtually all age groups, including baby boomers and millennials. It has been embraced perhaps most enthusiastically by people in their 20s, the cohort known as Generation Z.

There is an especially insidious aspect of the so-called “right to die.” It tends to expand. Beginning with seeking to end unbearable physical suffering, it has moved on to being seen as a solution for chronic debilitating conditions such as dementia. It even provides a rationale for suicide in general, legitimizing it as the answer to less specific forms of distress, such as unhappiness, emotional trauma or frustration with one’s circumstances.

And strangely, there are those who see it as the fitting “completion” of a life that hasn’t involved suffering at all. According to this thinking, if I’ve come to the point where I’m happy and fulfilled, if I’ve accomplished everything I set out to accomplish, why not end on a high note? Circumvent the pains and travails of old age by dying early.

Eventually the “right” to die moves beyond autonomous choice, transforming into active euthanasia and imposing itself on others.

In the Netherlands, which has long been an assisted-suicide trailblazer (only slightly ahead of other European societies), there is broad acceptance of death for the mentally incapacitated. Increasingly, dementia patients are being euthanized. A recent report tells of an old woman who tried to fight off a doctor advancing on her with a needle while being held down by her family members.

The notion of individual autonomy contradicts Judeo-Christian tradition, which has always maintained that we do not live isolated, self-contained lives, but, rather, we have an effect on one another. How we live, how we believe, how we die — in other words, the respect we show for our own lives — is important. It sends a message to other people. It impacts society.

Senior citizens (like me) have a particular and immediate stake in the assisted-suicide issue as the health care debate rages on.

From the early days of the Affordable Care Act, the government has vehemently denied that there are any kind of “death panels” at work making judgments about which patients will be granted or refused which treatments. But the truth is that protocols and standards are an intrinsic part of medical practice and insurance claim evaluations.

Whether we are talking about “Obamacare,” “Trumpcare” or private insurance, we have to look closely at what treatment procedures are precluded, accepted or favored. I know of a woman in California whose insurer denied her chemotherapy because of the expense, but approved coverage of physician-assisted suicide. There was a similar case recently in Oregon.

In both of these states, where physician-assisted suicide is legal, the “right to die” is shading into a “duty to die”: I have to die for the good of society. I must not be a burden to my family. I can’t be a drain on society’s resources.

These ideas are being heard more and more. They play into our deepest human feelings, and they are worrisome signs for our future.

We have to ask: Who is really making the decisions? Have we given insurers — or the government — control over our lives? There are fundamental moral questions involved here. And they must be answered.

Hard cases make bad law. No matter how much sympathy we may feel for people like Noel Conway, no matter how much we may fear our own suffering, there is no “right” to die. Only God has authority over life: when it begins and when it ends.

Father Michael Orsi is a parochial vicar at St. Agnes parish in Naples, Florida.

He’s the former chaplain and research fellow at Ave Maria School of Law.