Mariano Gómez Aranda
Throughout history, humanity has experienced many pandemics like coronavirus. The mid-14th Century witnessed what was perhaps one of the most terrifying epidemics in history: the Black Death, which lasted about seven years, from approximately 1346 to 1353. The disease spread very quickly with high mortality rates; it is believed that between 25% and 50% of the European population died as a result.
From a scientific point of view, many doctors wrote medical treatises attempting to explain the possible causes and consequences of the disease, as well as trying to offer remedies. In medieval times, when religiosity permeated all facets of life, religion remained closely intertwined with science. Christian, Jewish and Muslim doctors wrote treatises on the Black Death in which scientific explanations are entangled with religious ideas. In some cases, the texts are conditioned by the religion of their authors.
At what resulted in a pivotal moment in the middle of the 14th century, the Black Death also resulted in a rise in ‘fake news’ and xenophobia, which led to the expulsion, massacre and scapegoating of many Jewish communities. At the same time, it also marked a turning point in terms of the collective religious imaginary of the era. Rationalist interpretations of religious texts were introduced and provided a theological basis for the calls emerging from the medical community demanding sanitary measures in order to prevent contagion.
In the Christian sphere, among the numerous treatises on the plague, three of them are highlighted here.  Arrizabalaga, J. (1991). La Peste Negra de 1348: los orígenes de la construcción como enfermedad de una calamidad social. Dynamis, 11, 73-117. The first, entitled Pestilence Preservation Regime [Regiment de preservació de pestilència], was written in Catalan in 1348 by a doctor from Lleida named Jacme D’Agramont, who died of the plague shortly after finishing it. The second, also penned in 1348, was entitled A Compendium of the Epidemic, and prepared by a group of physicians from the Paris Faculty of Medicine at the request of King Charles IV of France. This group of doctors could be understood as the equivalent of what today would constitute a committee of health experts advising governments. The third, entitled, Treatise on the Epidemic (Tractatus de epidemia), was written in 1348 by an anonymous doctor from Montpellier, the location of one of the most important medical schools in the Middle Ages.
In the Jewish ambit, medical treatises are not as abundant, and they are not well known since many have not been even published. They are usually translations from Latin or Arabic to Hebrew, or written directly in Arabic. One of the most important is the treatise A Well for Life by Isaac ben Todrós, who lived in Avignon in the second half of the 14 Century.  Barkai, R. (1998). Jewish Treatises on the Black Death (1350-1500): A Preliminary Study. En R. French, J. Arrizabalaga, A. Cunningham, & L. García Ballester (eds.), Medicine from the Black Death to the French Disease (pp. 6-25). Aldershot-Brookfield-Singapore-Sydney: Ashgate.
In medieval Muslim World, there are also many treatises regarding the Black Death, and two stand out. The first, The Attainment of the Goal of the Seeker for Information concerning the Epidemic, was written in 1349 by Ibn Khatima, a Muslim doctor from Almería. The second is the work of the famous Ibn al-Khatib (d. 1375), a Muslim doctor who served as vizier to the Sultan of Granada, and is entitled A Useful Book for those Inquiring about the Appalling Illness.  For a discussion of plague treatises by Muslim authors as compared to those written by Christian physicians, an in particular regarding the concept of contagion, see Stearns, J. (2010). Infectious Ideas: Contagion in Premodern Islamic and Christian Thought in the Western Mediterranean. Baltimore: The Johns Hopkins University Press. For the treaty by Ibn Jatima, see Arvide Cambra, L. M. (2014-2017). El Tratado de la Peste de Ibn Jatima. Berlin: Logos. For the work of Ibn al-Jatib, see the German translation by M. J. Müller (1863). Ibnulkhatîbs Bericht über die Pest. In Sitzungsberichte der königlichen bayerischen Akademie der Wissenschaften zu München (Vol. 2, pp. 1-34). München: F. Straub.
The typical fake news linked to prejudice that we are so accustomed to today also existed in medieval times. At those times, these accusations unleashed a wave of Jewish persecution throughout Europe by angry, uncontrolled mobs, in which many Jews were killed, massacred, tortured or forced to leave their land and homes.
What information do these treatises provide us about the Black Death? How did they view the pandemic? Above all, how did their respective religions influence their considerations about this disease?
Explanations about the causes and effects of the disease correspond to the hypotheses of medieval medicine, which are based on the scientific theories of Greek authors such as Galen and Hippocrates, as well as on medieval authors including Avicenna.
The descriptions in these medieval treatises offer observations that the Black Death produced a high fever, cough, dry throat and general tiredness, symptoms that are very familiar to us today in the case of the coronavirus. However, the most important characteristic of the disease was the appearance of the well-known buboes—hence the name bubonic plague—which were abscesses of pus that could occur in the armpits, groins and other parts of the body. Jacme d’Agramont warned that there were cases in which plague patients had barely any symptoms, or were asymptomatic: they demonstrated little to no fever, there was no alteration in their pulse—which in the Middle Ages was a symptom of illness—and still, the patient would suddenly die.
A recent article observes that Ibn Khatima’s description of the causes of death in the case of medieval disease are very similar to those of death from COVID-19. Ibn Khatima explains that the plague causes a lack of pulmonar cooling of the innate heat generated in the heart (fever) and carried by blood (equivalent to the oxygen transport system). This process generates toxic residues (or free radicals), leading to an irreversible multiple organ failure, which causes death.  Herrera Carranza, M. (2021). Regarding Pandemics: Ibn Jatima from Almería Anticipates the Physiopathological Concept of Multi-Organ Failure in the 14th Century. Medicina intensiva 45,6 (2021) 362-370.
It should be noted that, from all these authors, the only one that refers to the origin of the 14th Century pandemic is Ibn al-Khatib, identifying China as the point origin. Many centuries later, Wu Lien-Teh (1879-1960), a Chinese epidemiologist famous for promoting the mask use during the 1910 Manchurian Plague, defended the theory that the Black Death began in China in 1346. Other scientists, however, contest this opinion and defend that it originated in the Crimean area.
All medical treatises on the Black Death claim that the disease was caused by corruption or putrefaction of air, and transmitted through air in the surrounding environment. Parisian physicians used to declare that, “bad air is more harmful than food and drink, because it quickly, maleficently reaches the heart and lungs.” The authors differ, however, with respect to the hypotheses about what causes this corruption. Jacme d’Agramont argued that the putrefaction of air could have been caused by bad vapors that mixed with air. He pointed out, like other authors, that putrefaction of air occurred after battles, when unburied corpses of soldiers rotted and polluted air. Putrefied waters could also produce pestilence when their vapors arose by the action of heat. Water humidity is transferred to air and mixes with it, causing its pollution. As is well known, humidity produces putrefaction. The Paris physicians argued that it was a simple natural change in the very substance of air.
To avoid air pollution, some preventative measures were recommended, like keeping rooms and houses well ventilated, and cities free of garbage (especially that of manure and animal entrails). It was also recommended to eliminate bad odors by burning aromatic herbs or fumigating with vinegar to purify air. Avoiding crowds was recommended to prevent transmission. Christian physicians often offered the famous advice to “go far away early, and come back as late as you can,” which was repeated ad nauseam.
However, in addition to the cause of corrupted air, medieval scientists, both Christian, Muslim and Jewish, agreed that God was the ultimate cause of everything. As for explanations as to why the Most High had brought about that plague, the authors differed.
According to Christians and Jews, the plague was God’s punishment for sins committed by human beings. Jacme D’Agramont defended this argument by citing various biblical verses. In Deuteronomy 28, God makes it very clear to the people of Israel that if they do not fulfill His laws, they will receive punishment. He expressly refers to “the boils of Egypt, ulcers, scurvy and itch, madness, blindness and confusion of mind” (Deut 28:27-28). Agramont also cites 2 Sam 24, which recounts how the people of Israel were punished with a plague because of David’s sin. Similar arguments appear in the Jewish treatises. The premise of these observations was that if something had happened in the past, it could very well occur again in the present.
Agramont affirms that if the plague is caused by our sins, medicine is of little use. In these cases, the only recourse for human beings is to recognize their faults and plead to God, as Solomon recommended in his speech consecrating the Temple (1 Re 8). He explicitly mentioned that, when there is famine, pestilence or any kind of plague in a land, God would listen to his people’s plea if they repented (1 Re 8:37-40).
In the case of Muslim authors, God was also cited as the ultimate cause of the plague and of pandemics in general. However, while they also proposed a hypothesis of divine punishment, they do not insist on this concept, but rather on the idea that illness is God’s will, and no human can avoid it. The underlying thought of these observations is that God is omnipotent, and therefore He is the cause of each and every thing that happens in this world.
Ibn Khatima, however, opposed the idea that the plague was a divine punishment. He interpreted the concept of “punishment” not in its literal meaning, but in a figurative sense similar to “suffering” or “disease” that God caused his believers in order to test them. Ibn Khatima referred to prophet Mohammed’s testimony, who described the plague as an agony that God sends to any person he wants, and whoever resigns to the plague and dies is considered as a martyr who will ultimately receive divine mercy.
In Christian and Jewish treatises, the influence of the stars was cited as causing the disease, specifically the conjunctions of Jupiter and Saturn. According to medieval astrology, the conjunction of these two planets announced profound historical changes for humanity. It was said that the origin of the three monotheistic religions was announced by conjunctions of Jupiter and Saturn, which had occurred previously in key moments related to these religions.
In the case of the Black Death, the physicians of Paris informed on a Jupiter and Saturn conjunction with Mars on March 20, 1345 at 1:00 in the afternoon, citing it as the origin of the disease. They even point to the source in which this assumption was based: On the Properties of the Elements [De causis proprietatum elementorum], attributed to Aristotle and commented by no other than Albert the Great, who was considered a completely reliable source of knowledge. The physicians in Paris provided a “scientific” argument for this influence: when they are in conjunction, these planets, due to their intrinsic characteristics, cause pestiferous, putrid and poisonous vapors to enter air. In consequence, disease is spread by these vapors.
In the Middle Ages, the idea that stars influence terrestrial events put into question the belief in the absolute power of God, since it could be interpreted that stars exert their own power, which is different from that of the Most High. Aware of this theological issue, the Jewish doctor Isaac ben Todrós explained that the heavenly bodies which produced the Black Death did not act alone, but with the power bestowed on them by God. He defines stars as “an ax in the hands of the craftsman,” and argues that their ability to determine the good or evil in humanity depends exclusively on God. We find similar explanations from other authors.
Ibn al-Khatib mentioned astrologers’ interpretations that the conjunction of planets caused the plague, but he himself did not follow this opinion. Ibn Khatima, on the contrary, thought that there may be an astral influence on the air’s corruption.
Ibn Khaldun, author of the famous “Muqaddimma” or “Introduction to history,” was the best proponent of rejecting the stars’ influence on events in the terrestrial world. He was one of the direct witnesses of the 14 Century plague. Ibn Khaldun rejected astrology due to the sole reason that God is the cause of everything that happens in the universe, and there can be no other cause apart from Him. Moreover, he cited two statements of the prophet. The first is: “The sun and the moon do not eclipse to announce death or life.” The second is: “Among my faithful there are those who believe in me and those who do not. Those who say, ‘The rain has fallen by the grace and mercy of God’ believe in me; those who say ‘The rain has fallen because of an astral conjunction’ do not believe in me, but in stars.” Ibn Khaldun concluded that astrology is a useless activity from the point of view of both religion and science.  Ibn Jaldún, A. a.-R. b. M. (2008). Introducción a la historia universal (al-Muqaddima). Córdoba: Umbriel, p. 1054.
In the plague of 14th century, Jews were generally accused of having caused the disease. The typical fake news linked to prejudice that we are so accustomed to today also existed in medieval times. At those times, these accusations unleashed a wave of Jewish persecution throughout Europe by angry, uncontrolled mobs, in which many Jews were killed, massacred, tortured or forced to leave their land and homes. Even the ecclesiastical authorities had to try and intervene to stop the attacks, and Pope Clement VI issued several papal bulls throughout 1348 in which he exonerated the Jews of having caused the disease.
Christian physicians admitted without problems that the Black Death spread from person to person via simple contact. They also pointed out that a healthy person should have a natural predisposition to develop the disease after having contracted it. Not all those who were in contact with patients developed the disease, and it was believed that this depended on the natural constitution of the body, the equivalent of an individual’s immune system as we understand it today. The Catalan doctor Agramont pointed out that the individuals who ate and drank excessively were more likely to develop the disease. Today, it is argued that the obese are more predisposed to COVID-19.
The anonymous doctor from Montpelier insists on contagion via breath but also through visual contact. The latter idea was associated with the evil eye, a very widespread and popular superstition in the Middle Ages. Even medical treatises at the time tried to provide scientific arguments to support this superstition. Enrique de Villena, in the first half of the 14th century, wrote a Treatise on fascination or the evil eye, in which he informs of people who can cause diseases with their eyes, arguing that the transmission of negative influence outside of the body can change its internal composition. In his work completed in 1437, The five figurative paradoxes [Las çinco figuratas paradoxas], Alfonso Fernández de Madrigal, known by the nickname “El Tostado,” discussed plague contagion. He described it as a process transmitted through vapors from the breath of a patient to a healthy one. He also added that the eyes of the sick can also transmit some subtle substances imperceptible to the eye, which corrupt healthy individuals having a certain predisposition for sickness.  Alfonso Fernández de Madridal, El Tostado, Las çinco figuratas paradoxas. Edición, prólogo y notas de Carmen Parrilla, Alcalá de Henares: Universidad de Alcalá 1998, págs. 448-450
However, the idea of contagion posed a major theological problem for Muslim physicians who wrote about the Black Death. In the Muslim tradition, Prophet Mohammed denied the existence of contagion. In a citation by Ibn Khatima, the prophet affirmed, “There is no contagion, no bad omen, no worms, no owl.” Traditionally, it was interpreted that what Mohammed meant was a rejection of superstitions associated with those concepts, because believing in them would imply doubting divine omnipotence. Those interpreting these traditions deduced that Mohammed’s denial of contagion demonstrated opposition to belief in astrologers, sorcerers, fortune-tellers and necromancers.
Muslim doctors Ibn Khatima and Ibn al-Khatib were well aware that the epidemic was contagious, and defended this argument from a rational point of view. Ibn al-Khatib affirmed that the existence of contagion could be demonstrated by experience, deduction, sensation, observation, and many testimonies, i.e., the basic knowledge sources in Islam. Ibn al-Khatib alerted that contagion occured in homes when other people from outside came to visit the sick. He cited cases of people who chose to stay isolated, and thus avoided the disease. The example of Ibn Abu Maydan was presented, an individual who was aware that the disease was contagious and decided to lock himself in his house, boarding up the door and remaining isolated, after having hoarded an array of provisions.  Arjona Castro, A. (1985). Las epidemias de peste bubónica en Andalucía en el siglo XIV: el médico granadino Ibn al-Jaṭīb, pionero en señalar la idea de contagio en esta enfermedad. Boletín de la Real Academia de Córdoba de Ciencias, Bellas Letras y Nobles Artes, 108-109, 49-58.
The doctor from Almeria, Ibn Khatima, said that the disease was transmitted by breath, through vapors generated by the body, when the patient’s clothes come into contact with the skin, or when people breath near these clothes. He provided examples of people who bought used clothes in the Almeria market, and died or became ill, after having come into contact with those clothes. However, Muslim doctors understood that in order to defend the idea of contagion, they had to offer theological and exegetical arguments to explain why the prophetic tradition denied its existence.
Ibn al-Khatib warned against the danger of not accepting the idea of contagion, given that it jeopardized the lives of many, and ultimately put the entire Muslim community at risk. In other words, he used an argument with deep Islamic roots: in the case of Black Death, the welfare of the community, which is the goal that every Muslim should seek, depended on the correct interpretation of the concept of contagion. If the concept was rejected, the central purpose of seeking the welfare of the Muslim community was also rejected.
At the same time, Ibn al-Khatib also used an exegetical argument: if a prophetic tradition contradicted sensory perception and appearance, it necessarily had to be interpreted and reinterpreted. This is a rationalist principle widely employed in Biblical and Quranic exegesis by interpreters of the three religions. In addition, Ibn al-Khatib cited other sayings of the Prophet defending the existence of contagion, such as when Mohammed said that the owner of healthy animals should not approach the owner of sick animals, indicating the potential approval of the contagion concept. Ibn al-Khatib finally argued that contagion is not a legal or religious question, but rather a medical issue.
Ibn Khatima dedicated chapters seven to ten of his treatise—some 40 pages in Arvide Cambra’s translation—to the question of contagion in the prophetic tradition. According to him, what Mohammed rejected was the idea that some things influence others by their very nature, because there is no action other than that which comes from God. According to Ibn Khatima, in the prophetic tradition Mohammed did not use contagion in a medical sense, but rather as a synonym for superstition. It is a rationalist explanation that attempts to reconcile science and religion.
Following the analysis of medieval scientific texts dealing with the Black Death, we can conclude that religion significantly influenced explanations about the disease’s ultimate cause: for Christians and Jews, it was divine punishment for sins committed by humans, while for Muslims it was a manifestation of God’s will to test believers. For some medieval scientists, the idea that a conjunction of planets was the cause of the disease did not entail any religious conflict; however, others felt the need to justify that planets do not act by their own volition, but rather instruments in God’s hands. Whereas the Christians did not see any religious obstacle to admit that the Black Death spread by contagion among individuals, Muslim doctors, although accepting this scientific hypothesis, were compelled to justify rationally the existence of a prophetic tradition which could be interpreted as calling into question the existence of contagion. Science and religion in the case of the Black Death remained closely interrelated, influencing each other in a constant and fluid dialogue.