Living in the 14th century was no good, no matter whether you were in Asian or Europe. In Asian, China was ruled by Mongolians, a dynasty characterized by discrimination (against the Han native, which accounted for 90% of Chinese population), constant hunger, and rampaging plagues. In Europe, famine, wars, and the “great mortality” killed half of European population.

In Europe, the 14th century is a critical period. Because of the massive decrease of population, the social structure and the role of religion changed dramatically. Skilled labors and unskilled peasants were both in need. Hope was lost and pragmatism replaced idealism. Illuminated scholars turned their interests from philosophy to concrete science. To some extent, the empirical science was burgeoning before Locky wrote his famous books.

Similarly, in China, the suppressed Chinese intellectuals wandered their ways to less philosophical things. Drama was the most celebrated achievement during the Mongolian dynasty. However, the drama language was rogue, the content was lewd, and the plot was ridiculous. The appealing to common people reflected the decreased morality of the society.

These miserable things all happened worldwide at the same time, not by coincidence, but by a microscopic organism—the Yersinia pestis. It caused the Black Death, characterized by either coughing blood (pneumonic plague), or swollen lymph nodes in the neck, armpit, or groin (the bubonic plague), or blood poisoning (septicemic plague). The fatality rate was about one third, with the greatest in septicemic plague, and smallest in bubonic plague.

The main culprit of the Black Death, called “the great mortality” in the 14th century, is black rats, specifically the rat fleas. The fleas can jump to human beings occasionally. However, Japanese research, conducted on Chinese during the World War II, proved that human flea can spread the bacteria too (curse Japan forever). It may explain why in Europe, there were lots of people dying while little mention about the death of mice.

The disease spread from the east to the west through the northern Russian route newly opened by Mongolians. The bacteria was a natural habitant in the Mongolian prairie and Gobi desert, living on the black rats and other rodents. It by chance crossed the line to our human beings. Nevertheless, in 1335, China was infected by the bacteria, and in 1347, it reached Europe.

Imagine that town by town, a merciless invisible Satan was collecting unfortunate souls. Such a terror was definitely unbearable for medieval people, most of whom were pretty ignorant about everything. Very often, months before the plague came, the scared people started to employ some preventive measures, all but one of which failed. Italian Florence invented many public health interventions such as clean water, garbage collection, and quarantines, but still lost one third of its population. The most effective way was to leave the infected towns, which again facilitated spreading the disease.

Facing the greatest threat, it was surprising that there were very few riots against the Church and governments, although the distrust in the Church was certainly planted during the plague. In England, many officials were still dutifully collecting tax, and most towns still held their common social events. Wedding and birth ceremonies appeared as regularly as possible. Even the funerals were normal except for too frequently. People merely accepted the fate. That is, God was furious and wanted to punish His children.

However, there was a scapegoat medieval Christians could blame on– Jews who was condemned in the Bible. Rumors were circulating that Jews were poisoning wells to kill Christians so that they could take over the world again. Therefore, an efficient prevention would be to burn all Jews in their communities. It happened in Southern France, Spanish, and German, except Poland. Fortunately, the Pope, Clement VI, rejected the idea that the plague was caused by the Jews. He argued that Jews were also dying of the disease, and he had no evidence that Jews were poisoning the wells. Partially owing to that, a large number of Jews were saved to “witness the almighty work of the God.”

There was another oddity that seemed ridiculous to modern people. A religious sect called flagellants who self-flogged severely to atone their (and others’) sins. This sect was originated in German and died out quickly after the plague. But the movement had significant implications. It suggested that common people started to disbelieve the teaching from the Church. Instead, they thought they could save themselves by their own atonement.

The medieval society started falling down after the massive deaths. Morality degraded. People enjoyed luxuries and wines after the plague was gone. In some areas, people even copulated publicly. Distrust was pervasive. Friends turned against friends, parents against children and vice versa. Good priests died and bad ones left. The Church was as helpless as everyone else. It has been said that those who survived from the plague were mean people. Good people who were willing to help others contracted the plague and died. It was a hopeless world during the plague and after the plague.

The devastating consequences of the plague in Europe were illustrated in a recent book “The Great Mortality, An Intimate History of the Black Death, the Most Devastating Plague of All Time” by John Kelly. The book depicted how the plague started in Europe, how it traveled across Europe, and what the preventive measures medieval people employed to fight again the plague.

Well, I was supposed to write a review on this book, but ended up talking about the plague itself. The book was a good record of history. In particular, it quoted many common people’s experience. However, the book lacked one characteristic which makes one book great. In Kelly’s book, there was no deep reflection on why the plague happened that way in some specific towns. Instead, the book described plagues from one city to another, embedding some superficial discussions on public health measures, society changes, and the plague mortality. Readers easily get bored after lines and lines of repeated sceneries. It was probably more enlightening if the author focused on two countries, for example England and German. In England, there were little disruptions in society, while in German, religion rebelling and Jews massacre were pervasive. In fact, there are many books on the plague itself, but few on the comparison. The book failed to identify this niche.

Furthermore, the book spent little effort on the implications of plague. Prospectively speaking, modern people don’t care much about how medieval people died. We want to know how they responded to the plague, and what the impact the plague had on human society. The author, unfortunately, neglected these issues.

Nevertheless, the plague wiped out one third of European population. It is an important event in human history. It even has evolutionary role in human species. Studies have suggested that the plague might selectively killed people who lacked a certain gene mutation. Human beings may actually benefit from the plague.

Unfortunately, the survival genes are more selfish than before.