What happened? It took Gibbon six volumes to describe the decline and fall of the Roman Empire, so I shan’t embark on that. But thinking about this almost incredible episode does tell one something about the nature of civilisation. It shows that however complex and solid it seems, it is actually quite fragile. It can be destroyed. 

What are its enemies?

Well, first of all fear — fear of war, fear of invasion, fear of plague and famine, that make it simply not worthwhile constructing things, or planting trees or even planning next year’s crops. And fear of the supernatural, which means that you daren’t question anything or change anything. The late antique world was full of meaningless rituals, mystery religions, that destroyed self-confidence. And then exhaustion, the feeling of hopelessness which can overtake people even with a high degree of material prosperity. 

There is a poem by the modern Greek poet, Cavafy, in which he imagines the people of an antique town like Alexandria waiting every day for the barbarians to come and sack the city. Finally the barbarians move off somewhere else and the city is saved; but the people are disappointed — it would have been better than nothing. Of course, civilisation requires a modicum of material prosperity—

What civilization needs:

confidence in the society in which one lives, belief in its philosophy, belief in its laws, and confidence in one’s own mental powers. The way in which the stones of the Pont du Gard are laid is not only a triumph of technical skill, but shows a vigorous belief in law and discipline. Vigour, energy, vitality: all the civilisations—or civilising epochs—have had a weight of energy behind them. People sometimes think that civilisation consists in fine sensibilities and good conversations and all that. These can be among the agreeable results of civilisation, but they are not what make a civilisation, and a society can have these amenities and yet be dead and rigid.
The peculiar predicament of the present-day self surely came to pass as a consequence of the disappointment of the high expectations of the self as it entered the age of science and technology. Dazzled by the overwhelming credentials of science, the beauty and elegance of the scientific method, the triumph of modern medicine over physical ailments, and the technological transformation of the very world itself, the self finds itself in the end disappointed by the failure of science and technique in those very sectors of life which had been its main source of ordinary satisfaction in past ages.As John Cheever said, the main emotion of the adult Northeastern American who has had all the advantages of wealth, education, and culture is disappointment.Work is disappointing. In spite of all the talk about making work more creative and self-fulfilling, most people hate their jobs, and with good reason. Most work in modern technological societies is intolerably dull and repetitive.Marriage and family life are disappointing. Even among defenders of traditional family values, e.g., Christians and Jews, a certain dreariness must be inferred, if only from the average time of TV viewing. Dreary as TV is, it is evidently not as dreary as Mom talking to Dad or the kids talking to either.School is disappointing. If science is exciting and art is exhilarating, the schools and universities have achieved the not inconsiderable feat of rendering both dull. As every scientist and poet knows, one discovers both vocations in spite of, not because of, school. It takes years to recover from the stupor of being taught Shakespeare in English Lit and Wheatstone's bridge in Physics.Politics is disappointing. Most young people turn their backs on politics, not because of the lack of excitement of politics as it is practiced, but because of the shallowness, venality, and image-making as these are perceived through the media--one of the technology's greatest achievements.The churches are disappointing, even for most believers. If Christ brings us new life, it is all the more remarkable that the church, the bearer of this good news, should be among the most dispirited institutions of the age. The alternatives to the institutional churches are even more grossly disappointing, from TV evangelists with their blown-dry hairdos to California cults led by prosperous gurus ignored in India but embraced in La Jolla.Social life is disappointing. The very franticness of attempts to reestablish community and festival, by partying, by groups, by club, by touristy Mardi Gras, is the best evidence of the loss of true community and festival and of the loneliness of self, stranded as it is as an unspeakable consciousness in a world from which it perceives itself as somehow estranged, stranded even within its own body, with which it sees no clear connection. But there remains the one unquestioned benefit of science: the longer and healthier life made possible by modern medicine, the shorter work-hours made possible by technology, hence what is perceived as the one certain reward of dreary life of home and the marketplace: recreation.Recreation and good physical health appear to be the only ambivalent benefits of the technological revolution.
Why aren't you in school? I see you every day wandering around.""Oh, they don't miss me," she said. "I'm antisocial, they say. I don't mix. It's so strange. I'm very social indeed. It all depends on what you mean by social, doesn't it? Social to me means talking to you about things like this." She rattled some chestnuts that had fallen off the tree in the front yard. "Or talking about how strange the world is. Being with people is nice. But I don't think it's social to get a bunch of people together and then not let them talk, do you? An hour of TV class, an hour of basketball or baseball or running, another hour of transcription history or painting pictures, and more sports, but do you know, we never ask questions, or at least most don't; they just run the answers at you, bing, bing, bing, and us sitting there for four more hours of film-teacher. That's not social to me at all. It's a lot of funnels and lot of water poured down the spout and out the bottom, and them telling us it's wine when it's not. They run us so ragged by the end of the day we can't do anything but go to bed or head for a Fun Park to bully people around, break windowpanes in the Window Smasher place or wreck cars in the Car Wrecker place with the big steel ball. Or go out in the cars and race on the streets, trying to see how close you can get to lampposts, playing 'chicken' and 'knock hubcaps.' I guess I'm everything they say I am, all right. I haven't any friends. That's supposed to prove I'm abnormal. But everyone I know is either shouting or dancing around like wild or beating up one another. Do you notice how people hurt each other nowadays?