First of all, the people of the Middle Ages faced the problem of the lack of currency. Without currency, there can’t be commerce, there can’t be a government, and the economy is reduced to local exchanges, which is very inefficient. The Roman currency was based on gold and silver, but the mines were flooded and abandoned, the precious metal of the Empire had either gone to China or was buried underground as the result of a deadly phase of deflation. There was no way to restart on a metal-based currency system.
Here, we see the first clever invention of the people of the Middle Ages: they created a virtual currency based on relics. Relics didn’t need gold or silver, they were mostly human bones that the Church, acting as a bank, would guarantee having belonged to some holy man of the past. That ensured the scarcity and the value of the relic-based currency. Relics also solved a basic problem: convertibility. Any currency, to be of any use, must be changeable into goods of some kind. With the economy having crashed, there was little in terms of goods to be purchased with any currency. But relics could be redeemed in terms of personal physical and spiritual health. That made people eager to have them as much, perhaps more, as they might be looking for gold and silver.
If relics solved the currency problem, an economy needs also roads, goods must be transported. We know that the Roman system of military roads had mostly collapsed during the 5th century, as Namatianus tells us in his “De Reditu Suo.” And, with the Roman state gone, there were no resources nor military needs for the maintenance of the roads. Here we have another clever invention of the Middle Ages: pilgrimages. People would travel all over Europe and even farther away in order to worship the most precious relics stored in churches and monasteries. Pilgrimages were said to be good for one’s spiritual health and well-being, but also moved a form of non-monetarized economy. Pilgrims needed food and shelter, and that generated a whole system of support for the travelers, monasteries, hotels, shelters, and the like. The local lords were encouraged to maintain the roads going through their domains, again in the form of the prestige they gained by favoring pilgrimages and the associated movement of goods.
Then, of course, commerce may take the form of a pilgrimage, but if people travel and exchange things they need to speak to each other. Here, we have another success of the Middle age: the people of that time managed to keep Latin alive as a European lingua franca. It was not everybody’s language, but an Irish monk could converse in Latin with a Sicilian monk. That prevented Europe from becoming an unmanageable Babel of languages (any reference to the current state of the European Union is intentional). Latin keep communications open and made it possible not only commerce, but also diplomatic relations among the various states and statelets.
Keeping Latin, of course, meant to keep the Roman law codes and, as a consequence, maintain the rule of law, one of the greatest conquests of the Roman civilization. Ah… but you are thinking of witch hunts, aren’t you? Weren’t Medieval people dedicated to burning poor women all the time? No, that’s part of the bad press surrounding the Middle Ages. Witches were NOT, emphatically not burned during the Middle Ages. Look at the data from a recent paper by Leeson and Russ. You see that trials and executions of witches were basically non-existent during the Middle Ages. The idea at some moment around the end of the 15th century. The peak was in the early 17th century — the age of Witch hunting was the so-called and, oh, so civilized “Reinassance”.
The use of Latin as not just a lingua franca, but also a sacred language, meant to create a body of European intellectuals, part of a network of monasteries, all managed by the Roman Church, and that kept alive the body of knowledge that had been gathered during the Classical Antiquity. But weren’t people burning books during the Middle Ages? Well, no. Book-burning was not an especially Medieval thing — you can see in the article by Wikipedia on the subject that book burning is mostly a modern thing. Besides, books written by hand were so expensive that nobody sane in his or her minds would engage in burning them.
As a final note, the Middle Ages saw an effort to control the violence of the military and with it the oppression of the poor, although that effort wasn’t so successful. During Roman times, soldiers would fight because they were paid and that allowed the government a tight control of the army. But, with the disappearance of currency, armies started fighting in order to loot, creating all sorts of disasters. One attempt to control them was the creation of military orders of warrior monks. During the early times of Christianity, the idea took the form of the militia of the Parabalanoi. They turned out to be unruly and violent, among other things they are said to have killed the Pagan intellectual Hypathia in 415 CE. They were disbanded and disappeared from history after the 6th century or so. Later on, military orders were created during the late Middle Ages and employed mainly for the Crusades, after the year 1000. The Teutonic Knights, the Templars, the Knights Hospitallers, and several others, turned out to be scarcely effective as a fighting force and difficult to control as well. The Medieval society remained socially stratified, but people such as Francis of Assisi made it clear that wealth was not the only goal worth pursuing. And the Middle Ages were a period of much better gender-equality than anything seen in Roman times. It was also a sustainable society that didn’t normally engage in soil destruction.
Then, of course, we know how it ended: with the great economic expansion that followed the Black Death in Europe, currency returned from new silver mines in Eastern Europe: the Medieval cult of relics became just a funny superstition. Now, armies could be paid again using metal currency and send to conquer the world that the new European galleons were discovering. The invention of the printing press created National languages and ended forever the role of Latin as an international language. National languages also created nation-states, aggressive and powerful entities that still dominate Europe today. And that created the world of today: aggressive, violent, destructive, unsustainable, and rushing at the fastest possible speed toward its own destruction — the Seneca Collapse of our civilization
For the Romans, it was inconceivable that there could be any kind of society without Rome as the capital of an empire, Rutilius Namatianus writes something like that in his De Reditu, during the early 5th century AD. Many people, today, seem to have the same attitude: they can’t conceive a civilization existing without fossil fuels.
But Namatianus was wrong: there was life after the collapse of the Roman Empire! Could we be wrong, too, in thinking that the end of fossil fuels will be the end of everything? The example of the Middle Ages tells us that it is possible to keep a sophisticated civilization despite the dearth of material resources available. It is likely that the old world can’t be saved anymore, and probably it doesn’t deserve to be. But maybe we could we be able to emerge out of the Seneca Bottleneck and build a sustainable society based on the rule of law that maintains at least some of the current scientific and literary knowledge
We cannot say if our descendants will be able to create such a world, but they will have a better chance if we help them. That means sowing the seeds of a renewable energy infrastructure based on sustainable resources, and to start doing that before climate change destroys everything. We can do that, but we need to start now.