Recently, seated in the audience of Michael Moore’s film Fahrenheit 9/11, I was struck, yet again, by a thought that has inspired much of my writing over the years — that life is a protracted exercise in defining the line between us and them.

In the case of Fahrenheit 9/11, the us and them refers to the haves and the have nots, or — according to Moore’s central thesis — those, on the one hand, who wield power and those, on the other, whose sacrifice on the battlefield secures that power.

The intriguing thing about the line between us and them is that it is fluid. With a simple smile on the part of Fortune, it is possible for “one of them” to become “one of us” — or, in this case, for a have not to become a have. The maddening thing about such fluidity is that it is exceedingly rare for a nouveau-have to imbue their new-found havitude with the attributes of have not-edness.

In other words — and this time in accordance with the rules of grammar — those who have the good fortune to cross over that thin line tend to travel light, rarely thinking to pack their ethics. Power corrupts. Absolute power corrupts absolutely. Orwell’s “Animal Farm” lives and breathes.

In the world of medicine, we see the phenomenon of the thin line operating at its most poignant in institutions that practise “ageing in place”, where the haves are possessed of their faculties, while the have nots are not. (“Ageing in place” refers to the practice, in some institutions, of allowing residents whose condition has declined to below hostel level to remain at the same institution, rather than being uprooted to a distant nursing home.)

In a strange inversion of the traditional social structure, it is the resident haves within this community who are the most dissatisfied. They are dissatisfied because they perceive themselves to be both besieged and beleaguered, by day and by night, by the frightening, zombie-like intrusions of the have nots, for whom they profess pity, while at the same time expressing fear, loathing, disgust and contempt. But, more to the point, they are dissatisfied because they know that the only thing that can possibly save them from an eventual slippery descent into the same loathsome condition is death.

And yet, as sincere and as heartfelt as may be the pity and empathy felt for these poor creatures by both their peers and their carers, there is no denying the doggedness and the sheer ferocity of the contempt. “He’s lost it”, we caring professionals say, shaking our heads with what passes for concern.

The terminology is crucial.

— Lost what?
— What the rest of us still have.
— How could he have been so careless?
— He’s no longer to be trusted with anything of value. Take away his car. Remove him from his home. Take away his independence. Remove him from his family.
— This person is no longer fit to enjoy the privileges earned by those cautious enough not to lose what they still have.

And all of this masquerading under the banner of care. It is not something that we are aware of doing, nor is it the sort of behaviour we would ever admit to. But, if you listen carefully, you will hear a thousand examples of it every day.

But why? Why do we interpret as active and negligent a loss so utterly passive and ill-deserved?

The answer is the same answer that comes back to us every time we question the iniquity of humankind — fear.

We fear illness. We fear incapacity. We fear loss. We fear death. And what we humans do with the things we fear most is to subject them to the rigours of our most virulent contempt.

But there is another, far more prickly and elusive example of the us and them mindset that pervades medicine, and this is the dichotomy that exists between doctor (have) and patient (have not). In this context, the terms have and have not are used not so much in a socioeconomic sense as in the sense of having knowledge and empowerment.

Nowhere does the dichotomy between doctor and patient express itself with a more powerful sense of irony than in the mind of that most singular of individuals: the medico. For it is only within the person of the medical practitioner that doctor and patient meet head-on — buck naked and unadorned — with not so much as a privacy screen, a desk, a computer, a stethoscope or even a gusset behind which either can hide.

This doctor can hide no secrets. No matter how dire or how remote the possibility, no diagnosis is withheld from the patient, no potential side effect hidden, no sequelae suppressed. The burden of fear and concern is not lifted by the professional hand but, rather, transmitted by it. Unexpurgated.

For, regardless of the best efforts of the sundry medical bodies and boards to encourage doctors to seek arm’s-length professional help for their illnesses, each doctor consults daily, hourly, momentarily with his or her own inner patient.

We engage in this nefarious practice under the shameful cloak of daily living. We do it as we chew on our toast, or as we strain at stool, or cleanse our bodies, or fall, exhausted, onto our beds. We do it when no one else is looking, or listening, or paying us the slightest attention. For we know that it is unseemly. Unforgivable. But we cannot help ourselves.

Pain is no sooner suffered than interpreted, dyspnoea no sooner experienced than analysed, fever no sooner endured than investigated.

But even the most ambitious, astute and adroit of procedural cardiologists remains powerless in the face of his or her own unremitting chest pain. And even the most introspective of haematemetic gastroenterologists baulks at the prospect of visualising his or her own entrails.

There comes a time when the psychological defences crumble and the half of the medico that remains a practitioner must cross that thin line, thereby joining the frightened half that screams “patient!”.

No amount of prodding and reassurance from the Medical Board can remove the stigma from this crossing.

We are now become the object of contempt. And the more strenuously the opinion-makers of the medical fraternity deny it, the more corrosively the contempt seethes beneath the surface.

For this is the nature of the human condition. Whatever we cannot control, we fear. Whatever we fear, we strive to control. Whatever we seek to control, we subject to the most heinous contempt.

It is endemic, among patient and doctor alike. Nothing has changed since the coming of the first bubo.