There's no shortage of discussion about the political and economic fallout of that terrible East Coast autumn day. We are inundated with tales of the bravery of New York firefighters, of treachery among Afghan tribal leaders and of parlous airline finances. But if that is the world outside, what of the world within? What has been the psychological fallout of the poisonings, explosions and wars? It's common to speak of people experiencing a state of shock, even those unaffected directly by events – something that should perhaps lead us to question how we include people under the heading "directly affected". There should maybe be space for anyone who feels that the ground beneath their feet no longer seems quite so stable.
The other night, in the early hours, unable to sleep, I watched an American TV discussion programme on the troubled times. "How can people learn to cope with the new world situation?" the interviewer asked. A panellist, a wise old owl, answered that we all had to learn to be more "philosophical", which, he added, we no longer knew how to be in the West. It was then time for the ads, and the point was left unexplored, but it left me thoughtful, reflecting on a contrast between our modern attitudes to life and a "philosophical" one; and, more particularly, on a possible shallowness in the modern attitude, which had left us psychologically unprepared for events. In which case, what exactly would it mean to be more philosophical, and how could it benefit us?
Turn to the OED, and "philosophical" is defined as: "Befitting or characteristic of a philosopher; wise; calm; temperate." Of course, most philosophers today are far from those things: they're timid, anxious men (rarely women) who haunt universities with egg on their beards and transatlantic lags in their conversation. And yet historically, one school of philosophers has coloured what we ordinarily mean by "philosophical". The school flourished in ancient Greece and Rome between the third century BC and the second century AD. It was nicknamed "Stoicism" after the Stoa Poikile, a hall near the central marketplace of Athens, where the movement's founder, Zeno of Citium, started teaching. Being a Stoic has come to mean, according to the OED at least, almost the same as being a philosopher: "One who practises repression of emotion, indifference to pleasure or pain, and patient endurance."
It's striking how two key modern assumptions fly in the face of what the Stoic philosophers believed. One of them might be called the assumption of "control". An idea has grown up in the minds of many that man is essentially in control of his destiny; he doesn't any longer have to be a plaything of random forces, and, with the application of reason, all his problems may be solved. Aeroplanes can be made to fly safely through the sky, nature can be tamed, the mind controlled. Hence the shock when a jet plunges into suburban New York or fanatics stuff white powder into envelopes.
Then there's a second modern assumption, which we could call "optimism". The tremendous advances in science and the relative safety and reliability of the developed world lead us to feel optimistic about the future. We are taught to expect that things will be better next year than this and, particularly in America (which bleeds its ideology across the developed world), that we all have a right to happiness.
Nothing could be farther from a Stoic mindset. The Stoics built their philosophy on two central tenets: first, that we do not always control our world, and, second, that we should be prepared for disaster to strike at any point. They taught those things not in order to depress their readers, but simply to prepare them for reality.
Who were their readers? Curiously, people a little like us. Stoicism became most popular in the Roman empire during the first and second centuries AD. Like the empire of the United States, the empire of Rome was extraordinarily sophisticated technologically and politically. Its great cities were the envy of the world; its mighty aqueducts testified to the Romans' willpower and resources. There was optimism and a sense of control. And yet things kept going wrong: earthquakes destroyed Pompeii; fires burnt Lyons and Rome; German barbarians launched terrorist invasions across the northern borders. The citizens of Rome were left shocked by such events. Stoic philosophy helped them to cope.
One great idea lies at the heart of Stoicism: that the world is a frustrating, dangerous place where we must steel ourselves for the countless disasters we may face. It teaches us that we best endure those frustrations that we have prepared ourselves for and understand and are hurt most by those we least expect and cannot fathom.
One of the greatest Stoic philosophers was the Roman statesman and writer Seneca (AD1-65). He tried to cajole us to be more pessimistic about how things would turn out. We must, he stressed, expand our sense of what may go wrong in our lives, which in the modern day should include buildings that suddenly collapse and aircraft that drop out of the sky. No one should undertake a journey by car or walk down the stairs or say goodbye to a friend without an awareness – which Seneca would have wished to be neither gruesome nor unnecessarily dramatic – of fatal possibilities. "Nothing ought to be unexpected by us. Our minds should be sent forward in advance to meet all the problems, and we should consider, not what is wont to happen, but what can happen. What is man? A vessel that the slightest shaking, the slightest toss, will break. A body weak and fragile."
If we do not dwell on the risk of sudden disaster and pay a price for our innocence when the World Trade Centre blows up, it is because reality comprises two cruelly confusing characteristics: on the one hand, continuity and reliability lasting across generations; on the other, unheralded cataclysms. We find ourselves divided between a plausible invitation to assume that tomorrow will be much like today, and the possibility that we will meet with an appalling terrorist event after which nothing will ever be the same again. It is because we have such powerful incentives to neglect the latter that Seneca asked us to perform a strange exercise every morning, which he called, in Latin, a praemeditatio – a premeditation – which involved lying in bed before breakfast and imagining everything that could go wrong in the day ahead. This exercise was no idle fun; it was designed to prepare you if your town burnt down that evening or your children died. "We live in the middle of things which have all been destined to die," ran one example of a premeditation. "Mortal have you been born; to mortals have you given birth. So you must reckon on everything, expect everything."
Does Stoicism mean accepting everything that life throws at you – letting bin Laden go free and failing to investigate the black-box recorder of AA587? No, it simply means working out what battles you can win, fighting those, but accepting what you can't surmount with good grace. Seneca had an image with which to evoke our condition as creatures at times able to effect change yet always subject to external necessities. We are like dogs who have been tied to a chariot driven by an unpredictable driver. Our leash is long enough to give us a degree of leeway but is not long enough to allow us to wander wherever we please. A dog will naturally hope to roam about as it wants. But, as Seneca's metaphor implies, if it can't, then it's better for the animal to be trotting behind the cart rather than dragged and strangled by it. As Seneca put it: "An animal, struggling against the noose, tightens it... there is no yoke so tight that it will not hurt the animal less if it pulls with it than if it fights against it. The best alleviation for overwhelming evils is to endure and bow to necessity."
If there is one lesson that recent events have taught us, it is humility: about what we can achieve, about how sane and intelligent we are – a lesson in great contrast to the optimism, perhaps even arrogance, that came before. By turning back to the wisdom of the Stoic philosophers, we may find a helpful way of tempering some of our expectations and dampening our shock at disasters and bloodshed. When, AD65, Seneca was ordered to kill himself by the crazed emperor Nero, his wife and family collapsed in tears, but Seneca had learnt to follow the chariot of life obediently. As he calmly took the knife to his veins, he remarked – in a sentence we may be wise to repeat to ourselves every morning: "What need is there to weep over parts of life? The whole of it calls for tears."
Alain de Botton is the presenter of a six-part series on philosophy entitled 'Philosophy: a guide to happiness', showing on the Discovery Channel, starting on Saturday at 9.30pm and running for the next six weeks. An accompanying book, 'The Consolations of Philosophy', is published by Penguin, £6.99Reuse content