You are by nature an optimist, a happy idiot. No personal disaster or run of bad luck has ever shaken your faith that the march of time brings progress. You believe the wicked eventually get their due. You’re confident that truth will come to light. You’ve never doubted that a hundred years hence, the world will be a better place.

Until lately. Lately you’ve found yourself wondering if the end of civilization might be at hand, and you are not alone in your apprehension. Pessimism drifts in the air like a virulent pathogen, infecting multitudes. The media deliver daily reports of contemptible politicians and enraged mobs, religious fanatics and failed states, widespread unemployment and ecological catastrophe. A friend has been goading you to buy a gun and plenty of ammunition “before it’s too late.” (He owns more than thirty weapons himself: shotguns, hunting rifles, semi-automatic assault rifles, and an astonishing variety of pistols.) However you parse it, the future looks increasingly grim and Malthusian.

What happened? How did this collective despair displace the easy confidence of recent memory? The technological miracles of our enlightened age were supposed to banish ignorance and alleviate human suffering. It was only two decades ago that the Berlin Wall came down, prompting Francis Fukuyama to announce the triumph of Western ideals over the forces of tyranny, and proclaim that war had become obsolete. “What we may be witnessing,” Fukuyama famously gushed, “is not just the end of the Cold War… but the end of history as such: that is, the end point of mankind's ideological evolution.”

What happened, say Fukuyama’s detractors, is that his giddy post-historical prophecy failed to account for the second law of thermodynamics—the scientific principle that explains why an ice cube melts when placed in hot espresso, and why you can remember the past but can’t foresee the future. Reduced to its essence, the second law ordains that entropy increases over time. Or, to put it another way, deterioration, disarray, and disintegration are written into the cosmic bargain. Things fall apart; the centre cannot hold. Progress inevitably leads to annihilation. It’s the supreme paradox.

According to the second law of thermodynamics, the earth is destined to become a frozen wasteland, devoid of life—an outcome that’s beyond dispute. The end of the world isn’t slated to occur any time soon, however. Although the entropy of the cosmos is irreversibly on the rise, the entropy of its constituent systems fluctuates up and down at varying rates. Incongruously, disorder retreats in some provinces of the firmament even as it relentlessly advances in aggregate.

Rain occasionally falls on the Sahara. Mothers give birth amid the devastation of earthquakes and war zones. Empires rise, fall, and are superseded by new empires. The second law of thermodynamics decrees that ice cubes will melt in your espresso, but the freezer in your kitchen will create new ice cubes as long as it’s drawing energy from an outside source (thereby boosting the entropy in some other corner of existence). The second law of thermodynamics, in other words, does not stipulate a nonstop slide into the abyss. The ride down is likely to be unhurried, and interrupted by any number of uplifting diversions. The final unsparing destination probably won’t be reached until long after your charmed life has run its course.

Which doesn’t mean your current angst should be dismissed as unwarranted paranoia. Most people in your privileged Western milieu have spent their entire lives in a bubble of peace and prosperity, but to believe la dolce vita will continue forever is delusional. Sooner or later the party always ends. Every great civilization since antiquity has gone into decline, and you can’t really pin the blame on entropy. The fault, dear Brutus, is not in the second law of thermodynamics, but in ourselves. Ordinary human behavior has proven to be more than sufficient impetus for war, economic collapse, and myriad other far-reaching calamities. Accordingly, nobody should be surprised if one of history’s recurring periods of adversity turns out to be coming in for a landing, and it would be naïve to presume that such a downturn, whenever it arrives, will be brief. The era christened the “Dark Age” by Francesco Petrarca afflicted Europe from the Fall of Rome until the Renaissance, a span of some nine hundred years. For all anyone knows, we might be witnessing the onset of a similarly protracted spell of gloom.

Predicting the future is a fool’s errand, of course. But whatever lies ahead, you can take some comfort in the weedy resilience of our species. If the world is in fact teetering on the brink of a new Dark Age, Homo sapiens will not lack strategies for coping. Toward that end, many people turn to religion during difficult times, although you happen to find literature more effective than scripture. When prospects grow dire, you derive courage and reassurance from writers as disparate as Thucydides, Walter Bonatti, and Cormac McCarthy. If the going gets especially tough, you consult Albert Camus.

In his book-length essay, The Myth of Sisyphus, Camus re-interprets the legend of the eponymous protagonist, for whom the gods concoct an infernal torture: For eternity Sisyphus must push an immense rock to the top of a mountain, only to have it tumble back to the depths of hell every time he approaches the summit, compelling him to return to the bottom and roll the rock uphill again and again. The gods, Camus explains, are convinced there is “no more dreadful punishment than futile and hopeless labor.” Each time Sisyphus trudges down to roll the rock back up the slope, “The boundless grief is too heavy to bear.”

Be that as it may, when Sisyphus finally manages to wrap his mind around the inescapability of his pointless burden, he is liberated from his torment. By acknowledging his predicament and taking responsibility for it, Sisyphus

drives out of this world a god who had come into it with… a preference for futile sufferings. It makes of fate a human matter, which must be settled among men. All Sisyphus’ silent joy is contained therein. His fate belongs to him. His rock is his thing…. [H]e knows himself to be the master of his days…. Thus, convinced of the wholly human origin of all that is human, a blind man eager to see who knows that the night has no end, he is still on the go. The rock is still rolling.

In Camus’ interpretation, Sisyphus concludes that “all is well,” despite the ceaseless privation he must endure: “This universe henceforth without a master seems to him neither sterile nor futile. The struggle itself toward the heights is enough to fill a man’s heart. One must imagine Sisyphus happy.”

As a gray-haired alpinista, you’ve spent the better part of half a century struggling on high escarpments, inventing purpose out of hardship, and conjuring meaning from otherwise pointless acts. For Sisyphus to be contented as he toils beneath his rock doesn’t strike you as implausible. But when you contemplate the uncertain future, and the Sisyphean tribulations it’s apt to impose, actual joy seems a little too much to hope for. All things considered, you’d settle for stoical resolve.