Although a computer language was named after the Seventeenth-century philosopher Blaise Pascal, he is now read more for his theology than his mathematics. Those interests coincided in one of his Pensees, known as the Divine Wager. Applying his ideas about probability, Pascal proposed that the safest bet was to live as if god existed. That calculus can be transposed to the debate over euthanasia.

Because Pascal believed that reason cannot tell us whether God exists, he depicted our decisions about how to live as if they proceeded from the toss of a coin. Heads, god exists. Tails, he does not.

In Pascal’s view, the odds are stacked against those who stake their happiness on a single human existence. We are not betting one lifetime on earth against an equal period after death. Eternity is an infinity of lifetimes. Hence, if a just god does exist, sinners will lose more in the hereafter than they could ever gain on earth from their “noxious pleasures, glory and good living”. To live as if an eternity of bliss or torment does not await us, Pascal concluded, is to take too big a risk.

Pascal’s life ended at thirty-nine years, in1662, after a long illness. His editor and translator for Penguin Books, A. J. Krailsheimer, reports that the “record of his last days is a melancholy and terrible one. The gruesome attentions of doctors as ingenious in devising treatment as they were obtuse in diagnosis make a distressing tale. Robbed of serenity and dignity, too sordid in its details for a shining example of heroic martyrdom, Pascal’s death agony represents the slow corruption of the flesh, poisoning even the mind until little is left to snatch away”.

If this account sounds like a case for mercy killing, Pascal would never have entertained that temptation. No matter how anxious he was to be united with his Saviour, Jesus Christ, he saw suicide as the unforgivable sin of despair against the infinite mercy of God.

Today, even Christians are less certain on that point. Indeed, for a majority of Australians, Pascal’s gamble is relevant primarily as a secular wager. When do the odds shorten sufficiently to make it a better bet to give oneself to death than to go on living? This version is far from a straightforward win-or-lose bet. The gamble is more like trying to pick the first three horses past the post than Pascal’s simple toss of a coin.

Pascal’s near contemporary, the medical practitioner Michel Montaigne, illustrated our dilemma with the case of a nobleman whose loss of a battle condemned him to being tortured to death the next morning. He could say: I have lived one day too long.

To avoid that fate, the German critic Walter Benjamin took a lethal dose on the night of 26 September 1940 after his escape from Vichy France had been blocked at the border into Spain. He was right to avoid capture by the Nazis, given his Jewishness and Communist connections. He could not have known that the rest of his group of refugees would be admitted a few weeks later.

Hence it is possible to go too soon. Throwing oneself off Sydney Heads the day after being diagnosed HIV-Positive is to miscalculate. The odds are against taking an overdose until the onset of secondary infections.

The wager nowadays is between the inevitability of death and the likelihood of “immobility, incontinence, or mental and emotional disabilities”, to repeat the concerns that the Nobel laureate Sir Macfarlane Burnett held for himself. The current debate over legalizing euthanasia concentrates on whether doctors should give us a parting shot a few days before we would die anyway. That release does not meet a wish to avoid “the slow corruption of the flesh” long before we approach death’s door.

To pass away in one’s sleep at the age of eighty without having known a serious illness would seem a consummation devoutly to be wished. Many of us hope for the instant extinction from stroke or heart failure. The statistics are against us. No more than one in ten of us will be snuffed out like a candle – a nuclear holocaust excluded.

Sherwin Nuland in How we die documents that dying is a process of falling apart. If only one could expire from cancer only of the breast. Instead, the entire system seizes up so that our vision and hearing are impaired, depriving us of the comforts of reading and music. Those secondary afflictions, like the drugs to combat them, strip the delights from taste and smell. Delicacies are forbidden by diabetes or organ failure. Meanwhile, hospitals seem incapable of providing a fresh pot of tea or a strong latte.

The secular wager is not just a bet on whether we will be punished for taking our own lives. Rather, it appears as a question of when to do so. Should we go while the going is good?

Quite a few AIDS sufferers decide to go early, as depicted at the start of the recent Australian film, Walking on water. Some cancer patients do too. One complication with Alzheimer’s is that if we wait till the last moment, we may forget to do it.

The hardest case is old age. If we reach eighty in fighting fettle, we are likely to risk soldiering on. For each day that passes beyond that birthday, the chance of a blow more terrible than death increases. The secular wager poses: are another five years of activity to eighty-five worth the chance of a year or two of decay between eighty-six and eighty-seven? To complicate the odds, the longer we have lived, the longer we are likely to linger after being struck down.

Thirty years ago, the seventy-three year old Macfarlane Burnett voiced the secular wager with the plea: “Don’t make me die twice”. He asked to be allowed to “go on to the end with as much dignity and as little pain as possible”. The length of further survival would have become immaterial. He carried a card with instructions not to be revived or placed in intensive care. Such cards and living wills have become widespread. Yet, relatives have to protect patients from medical professionals who strive too vigorously to keep existence going, tormenting us unto death.

It was all very well for Montaigne to advise that “One should be ever booted and spurred and ready to depart.” His successors have discovered ways of extending existence even though we patients cannot reach our shoe laces.

To be told that one has a terminal illness is bound to induce some degree of depression. Laws countenancing euthanasia have to allow for altered mental states. The definition of “being of sound mind” should not be the same after we have been diagnosed as terminally ill as it was when we believed ourselves hale. Melancholia in the dying is not a side-effect to be cured by electro-convulsive therapy. Rather, grieving for oneself makes a necessary contribution to our ability to undertake a rational choice about going before the dying gets out of our control.

Another complication in the secular wager is the prospect of being restored to a productive life. The case for suicide has to weigh its psychic demands on our dearest against the costs, monetary or otherwise, to the community from our holding out to the end. How much of the earth’s resources are we entitled to use? The answer varies according to the prospect of repaying the services rendered.

For instance, a seventy-year patient who is told that her sarcoma has returned and that a hind-quarter amputation is recommended can have no guarantee that the loss of a leg will prevent the cancer’s spread. Rather, the probability is that any time remaining will be spent learning to be one-legged while coping with terminal decay. Here, the personal and public costs appear weighted towards suicide.

On similar grounds, patients abandon chemotherapy because its poisoning deprives them of even the most meager of pleasures. In refusing that treatment, they are deciding to make the most of a brief period of life rather than to persist through an existence shorn of almost all attractions.

Those who conclude that the odds from lingering on are not the best bet still have to put that decision into effect. The concern to avoid the worst of dying extends to the method chosen to end one’s life. A failed suicide can plunge us into the dreadfulness that we had hoped to elude. An overdose on prescription drugs is becoming harder because of controls over pharmaceuticals.

Otherwise, pure heroin is left as a painless and fairly certain exit for those who have never used it. That inexperience, in turn, places its acquisition and administering far beyond the reach of most of us. How does one convince a dealer at first encounter that all one wants is a lethal hit?

The choice of method is linked to wishing not to be a burden in death any more than in life. The Australian founder of Pre-History, V. Gordon Childe, decided to die when he was sixty-five. He went mountain-climbing but left his spectacles behind so that he was almost sure to fall. That method highlights how an instinct to survive resists the wish to be gone. Did Childe suspect that, although he would never be able to throw himself off the edge, he could allow himself to slip? Respect for his decision to die does not extend to his putting others at risk in retrieving his body.  

Childe’s farewell letter concluded on a more attractive note: “I have enormously enjoyed revisiting the haunts of my boyhood, above all the Blue Mountains. I have answered to my own satisfaction questions that intrigued me then. Now I have seen the Australian spring: I have smelt the boronia, watched snakes and lizards, listened to the locusts. There is nothing more I want to do here; nothing I feel I ought and could do. I hate the prospect of the summer, but I hate still more the fogs and snows of a British winter. Life ends best when one is happy and strong”.

Even among those who say “Amen” to that sentiment, many of us will hang on in the most desperate circumstances. Existence chained standing on a ledge no bigger than our feet can seem preferable to nothingness. Manning Clark did not want to miss out on the experience of dying as part of living, and mounted a mighty struggle as his lungs filled with fluid. By contrast, Patrick White had often expressed a wish to be gone, yet, at the end, he too put up a ferocious battle to keep breathing.

For every person who will manage to exit in time, nine will put our money on some thousand-to-one shot by scouring the internet. As we scroll through the sites on that secular prayer-wheel, we know that its nostrums will be no more efficacious than the relic that is supposed to have cured Pascal’s niece of a fistula. The science that has increased our life expectancy has also shortened our expectation of a miracle, or of an afterlife. Meanwhile, the odds of encountering the miseries of Pascal’s deathbed remain at around even money.