Portents of Infection

Did Avicenna invent quarantine in the 11th century?

In the wake of the coronavirus crisis, numerous claims have been making the rounds of cyberspace to the effect that during the Middle Ages, Muslims had an almost modern understanding of infectious disease and the steps that should be taken to combat it. In particular, it is claimed that Islam implemented quarantine centuries before the practice became common in Europe during the Black Death.

In my previous installment, I discussed what Muslim scripture had to say on the subject of disease and quarantine, and how it was interpreted by the theologians of the time. The bottom line was that although there are passages about not entering or leaving areas where plague has broken out, they are more about patiently submitting to the Will of Allah, than about trying to divert His Will by taking steps to combat the disease.

But in addition to its theologians, the medieval Muslim world was known for its scientists. They were certainly ahead of the curve in many areas, including medicine, and in this installment I’m going to take a look at the state of the art of medical science, circa 1000 AD. I’m going to focus in particular on the king of all medieval Muslim physicians, Avicenna. Born in 980 in what’s now Uzbekistan, Avicenna was a Renaissance Man hundreds of years before the Renaissance, with accomplishments in mathematics, astronomy, chemistry, and poetry. He even served in government when a satisfied patient, the Emir of Hamadan, made him his vizier (prime minister).

But it’s for his medical works that Avicenna is best known. His Canon of Medicine was the textbook on the subject, both in the Muslim world and in Christendom, up until the 1600s. Some claim that he invented quarantine and even that he came up with the forty day isolation period, which later became common in Europe and gave the practice its name (quaranta is Italian for forty).

I thought it was suspicious that all the claims about Avicenna and quarantine came from secondary sources—no actual quotations—so I did some research and found no place in the Canon of Medicine or Avicenna’s other works where he recommends the practice. The earliest references I could find come from around 1500, when reformers like Ilyas bin Abram al-Yahudi, a Jewish convert to Islam, attempted to persuade a reluctant Ottoman Court to adopt state-of-the-art medical practices. In her excellent 2012 book, Plague, Quarantines and Geopolitics in the Ottoman Empire, Birsen Bulmus speculates that, “Perhaps Al-Yahudi sought to cover his own personal arguments – like his warning ‘not go in crowded districts’ – with earlier renowned authorities so that his recommendations would be accepted within literary Islamic traditions.”¹ In any case, al-Yahudi’s arguments fell on deaf ears—quarantine would not be established in the Ottoman Empire until 1838, and even then, only after considerable debate.

Indeed, it would have been strange for Avicenna to champion quarantine, given the understanding of health and disease that prevailed in his time. Despite the hype one hears about the great accomplishments of medieval Muslim physicians, it is, frankly, a mixed bag. They made great strides in diagnosing disease and assembling massive catalogs of symptoms. For example, A Treatise on Smallpox and Measles by Muhammad ibn Zakariyya ar-Razi (854-925), known in the west as Rhazes, is the oldest book we know of to distinguish between the two diseases (For an amusing story about Rhazes’s foray into psychology, see here). But when it came to understanding disease, and treating it, things were considerably more hit or miss.

The obstacle was that the germ theory of disease didn’t exist. The conceptual framework of medicine had not progressed since the time of the Ancient Greeks. The prevailing theory was Galen’s notion of the four humors—blood, phlegm, green bile, and black bile—and their corresponding properties of hot/cold and wet/dry. Under this theory, illness was the result of the humors getting out of balance, and the cure was to eat foods with opposite properties of temperature and moisture in order to compensate. Green bile, for instance, was thought to be hot and dry and therefore an excess of it caused fevers. Thus, to cure fever, the green bile needed to be balanced with something cool and moist. Although we do find some powerful drugs in the Muslim pharmacopeias—in a recent post about a tenth century cookbook, I included a recipe for opium-based cough drops—treatments were mostly food-based and bordered on quackery. In the case of fever, gourds and pomegranates were thought to be especially effective.

As for what causes the humors to fall out of balance in the first place, there were various theories.

Take smallpox, for example. Since Bubonic Plague was taking a rest—the aftershocks of the Plague of Justinian had died out around the end of the Umayyad Caliphate (750) and the Black Death of the 1300s was still centuries away—smallpox was probably the most dangerous disease with which the physicians of the Islamic Golden Age had experience.

Absolutely everyone got it, usually during childhood. Either they survived or they didn’t—the death rate was about 25%. If they survived, they never got it again.

Based on these observations, physicians concluded smallpox was just a normal part of growing up. Both Rhazes and Avicenna described it as a process of rot or fermentation in the blood. According to The Canon of Medicine,

Its symptomatic cause is the natural fermenting [or boiling] of the blood to shake out the remaining menstrual nourishment that was mixed in it from the time of pregnancy…like what nature does in squeezing the grape until it becomes a drink resembling its essence [i.e., wine].2

Still, this didn’t explain epidemics, why smallpox would break out in large numbers in certain times and places. Along those lines, Avicenna did have some rudimentary notion about contagion. One paragraph in The Canon of Medicine lists diseases that can be spread from person to person, and the manner in which they’re spread:

And among the diseases, some are contagious, like leprosy, scabies, smallpox, infectious fever, and festering wounds, especially where the houses are cramped, or likewise if the neighboring houses are downwind. Also conjunctivitis, especially from gazing into the eyes of someone else, and toothache from imagining biting into something acidic. Also pannus and leprosy.3

However, this was not so much due to the transmission of germs from person-to-person—Avicenna knew nothing of the variola virus—as it did with the presence of bad air, or miasmas, in certain places. Hence the significance of whether a house was closely confined or downwind from an infected house.

Sometimes the reason is that winds carry bad vapors from distant places that have stagnant water in them, or wounded bodies from battles, or those who died from fevers and weren’t buried or burned. And sometimes the reason is proximity to a neighboring place. And sometimes corruption is shown to be hidden in the ground for reasons not understood in detail. Then the water and the air are prepared and the fevers occur.4

Avicenna fills page after page describing how winds, seasons, temperature, humidity, and even the heavens affect the quality of the air. For example,

If we see the south wind increase, and days of turbid air, and then after that it becomes clear for a week, and then a cold night occurs that extends into a hot, hazy, cloudy day, then an epidemic might come that causes infectious fevers and smallpox and their like. And likewise if there was a cool summer and the atmosphere was heavy with soot. And comets, fires, and meteors in the fall are portents of infection as well.5

"As for improving the air," Avicenna writes,

...it is the goal to dry the air. Make the air good and prevent the rottenness from entering and crude matter from returning with ambergris, camphor, musk, and a measure of candy, storax, sandarac, asafetida, clove resin, mastic, terebinth resin, laudanum, honey, saffron, cypress, juniper, moss, bay leaf, sedge, 'adhkhar, savin, waja, shababk, bitter almonds, and so forth. And take these components in vinegar and asafetida and sprinkle the house...perfume with incense: sandalwood, camphor, pomegranate peel, myrtle, apples, quince, teak, tamarisk, and ribas. The perfuming must be repeated.6

This use of perfumes and incenses to fumigate the bad air was common practice. The historian as-Suyuti (d. 1505) tells of an incident during the "Plague of the Notables" (716-717), when a merchant appeared before the prince Ayyub, son of the Caliph Suleiman. The desperate courtiers grabbed the merchant's supply of musk right out of his hands. It didn't work though. When the merchant returned a week and a half later, Ayyub and all his household were dead and the palace boarded up.⁷

Clearly these three theories—maturation of the blood, person-to-person transmission, and miasmas—are not entirely consistent with each other, despite all appearing in the same book, and sometimes on the same page. The miasma theory is the one to which Avicenna dedicates the most space, and also the one which one hears the most about in the works of other authors. It is, of course, entirely at odds with the idea of quarantine.

If disease is the product of a foul and pestilent congregation of vapors that have accumulated in some place, then rather than hunkering down where you are, the logical thing to do is escape to some more wholesome locale. The chronicles of the Umayyad period are rife with accounts of rulers fleeing their palaces during outbreaks of Bubonic Plague. Finding higher ground was especially popular, since it was believed that the miasmas had an affinity for hollows and valleys. In the example I gave in my previous post, in which the Caliph Omar relocated his troops during the Plague of Amwas, their destination was the higher elevations of Hauran, in what's now southern Syria.⁸

Despite the vaunted reputation of medieval Muslim physicians in general, and Avicenna in particular, there is not only no evidence that they invented quarantine, but the idea wouldn't even make sense to them, given their basic ideas about medicine. Some of which were downright laughable. Obviously comets have nothing to do with smallpox, and even though conjunctivitis is highly contagious, spreading it requires some form of contact; you don’t get it merely by gazing into the eyes of someone who has it.

Still, we shouldn’t laugh too hard. Their painstaking classification of disease and symptoms laid the foundation for what was to come. The pioneers of modern medicine stood on the shoulders of giants, and Rhazes and Avicenna were giants indeed.

Michael Isenberg drinks bourbon and writes novels. His latest book, The Thread of Reason, is a murder mystery that takes place in Baghdad in the year 1092, and tells the story of the conflict between science and shari’ah in medieval Islam. It is available on Amazon.com Please follow Mike on Facebook and Twitter. Subscribe to Islam: the Good, the Bad, and the Everyday Photo credit(s): Ether Monument, Boston Public Gardens from Wikimedia Commons

¹Bulmus, Birsen, Plague, Quarantines and Geopolitics in the Ottoman Empire, Edinburgh: Edinburgh University Press (2012), p. 44.
²Avicenna, Qanun fi al-Tibb (Canon of Medicine), Book IV, Beirut: Muʻassasat ʻIzz al-Dīn (1987), Chapter 3, Section 67. All translations from The Canon of Medicine are mine.
³Avicenna, Qanun fi al-Tibb (Canon of Medicine), Book I, Beirut: Dar al-Kotob al-Ilmiyah (1999), Chapter 2, Section 8.
⁴Avicenna, Book IV, op. cit., Chapter 3, Section 65.
⁵Ibid, Chapter 3, Section 66.
⁶Ibid.
⁷See Michael W. Dols seminal article, "Plague in Early Islamic History," Journal of the American Oriental Society, Vol. 94, No. 3 (Jul. - Sep., 1974), p.379.
⁸Dols, op. cit., pp. 376-380.

Running from what Allah had ordained...

...to what Allah has ordained.
Islam and Plague Part 1: The Theologians.

When one thinks of the relationship between science and religion, the great historical conflicts between the two typically come to mind: the persecution of Galileo by the Roman Catholic Church, for example, or the trial of John Scopes for teaching evolution. Science makes some claim and Religion replies, “That’s heresy!”

But there’s another phenomenon that I've observed over the years. It's kind of the opposite: Science makes some claim, and Religion replies, “We knew it all along!”

Christian writers claim to find conservation of energy, the Big Bang Theory, and dinosaurs in the Bible. Hindus see Heisenberg Uncertainty in Vedic wisdom about the ultimate unknowability of reality. While I was growing up, I often heard my Jewish co-religionists express great pride that our Bronze Age ancestors were millennia ahead of the curve in their insight into the trichinella worm.

One example of this that is particularly timely, thanks to the coronavirus crisis, is that Islam had unique insight into infectious diseases and quarantine centuries before the advent of modern medicine. One hadith in particular (a hadith is a saying of Muhammad or one of his Companions) has been quoted in numerous articles, including this one in The New Yorker: “If you hear of an outbreak of plague in a land, do not enter it; but if the plague breaks out in a place while you are in it, do not leave that place (Sahih Bukhari, Volume 7, Book 71, Number 624).”

Or as today's Koronavirus Karens put it, "Stay the f--k home!"

As I shall show, the alleged foresight of medieval Islam regarding modern germ theory has been greatly exaggerated. Nevertheless, what Muslims did believe—though often contradictory—is interesting in its own right, caught up as it was with fundamental questions about God's power and human destiny. In this post I’ll explore what scripture and theology had to say on the subject. The views of Avicenna and other scientists will be the topic of a future post.

It is impossible to separate any discussion of Islam and plague from the faith’s core tenets, in particular the belief that Allah is all-powerful and everything that happens in Heaven and on Earth unfolds according to His Will. Muslim theologians, especially those of the Ashari school, argued that Will and omnipotence are in fact Allah’s primary attributes. He is not bound by any laws of nature or justice. Miracles are not a departure from the natural order because there is no natural order, no causation, only Allah’s Will. As for the will of human beings—so-called "free" will—there's no such thing as that either. That fantasy is pure blasphemy; it limits Allah's power.

The writings of the towering eleventh century scholar, Abu Hamid Ghazali, is representative of medieval theologians in general and the Ashari school in particular. He delves into the topic at length in his Revival of the Science of Religion in the chapter “Tawhid wa Tawakkal (Monotheism and Reliance on God)”: “Man's will and strength are guided by another,” he writes. “A man is the object or intermediary of God's will and power flow…He who attributes everything to anything other than God is misguided…Everything was written.” The last part echoes verses 54:52-53 of the Quran: "Everything they do is in the writings. And everything small and great is written down."

Such theology inevitably leads to fatalism, a reluctance to act in the face of the impossibility of changing Allah’s decrees. The best we can do is resign ourselves patiently to them, and rely on the benevolence of Allah to ensure that all will turn out well for those who believe. In modern times, Edward Said railed against this characterization of Muslims, which he saw as a racist stereotype: the passive “Oriental.”

But stereotype or not, there is no doubt fatalism is deeply rooted in Muslim scripture. A search on Quran.com for the word patient (صبر) turned up eighty-seven hits. Verse 29:58-60 is typical: “Excellent the reward of the workers, who are patient and on their Lord they rely! And how many a living creature carries not its sustenance! Allah sustains it and yourselves.”

Or as another religion put it, "Consider the lilies of the field; they toil not, neither do they spin."

In another work, The Book of Counsel for Kings, Ghazali told a rather poignant story about the impossibility of taking action to thwart what Allah has written for us. A companion of King Solomon saw Death eyeing him. Fearful that his end was imminent, he asked Solomon to use his magic to teleport him to India in order to escape Death's clutches. Once there, he died that very day. The story ends with Death telling Solomon that the reason he was staring at the man was that he was surprised that someone whose soul was destined to be collected in India could possibly be so far from there.

Even among those Muslims who were inclined toward a more scientific view of the universe, there was a fatalistic streak. It permeates the Rubaiyyat of Omar Khayyam for example. We are

Impotent Pieces of the Game He plays
Upon this Chequer-board of Nights and Days;

If you’ve read my novel The Thread of Reason, you know that despite their on-again off-again friendship, Khayyam and Ghazali were polar opposites, in both personality and in philosophy. When they agreed on something, it must have been deeply ingrained in the culture indeed.

And yet, Muslims are not entirely passive in the face of a deterministic universe. Like all of us, they plan, and work, and fight, as if doing so will have some effect on the world. They lock their doors to prevent thieves from stealing their property and repair their houses to prevent the walls from collapsing. They pray in the hopes of modifying heaven’s terrible decrees. The even eat.

With his characteristic disdain for those who disagree with him, Ghazali explains,

Some think that the meaning of God-reliance is to give up earnings, to give up efforts, and to lie upon the ground like [a] thrown plank or like meat on a [skewer of] wood. This is the conjecture of the fools, it is unlawful in Shari’ah which praises God-reliant men.

For example,

When you are hungry and food is placed before you it is not God-reliance to give it up. This is against law of nature. Similarly if you do not cultivate land and hope for crops or if you do not cohabit with [your] wife but still hope to have a child, it will be madness and not God-reliance.

He then provides a dozen anecdotes about saints who didn’t cultivate the land, or otherwise provide for themselves, and Allah provided for them anyway.

It’s a paradox. Ghazali quotes a hadith which captures it nicely: “The Prophet said to a desert Arab: Why have you let loose your camel? He said: I let it loose depending on God. He said: Tie it and depend on God.”

Or as another religion put it, “Put your faith in God, my boys, and keep your powder dry.”

Any discussion of Islam and medicine in general, and plague in particular, has to be understood in the context of this somewhat dual view of Allah’s omnipotence and man’s agency.

As with other things, Islam teaches that health and disease are entirely controlled by the Will of Allah. And even when there appear to be natural forces at play, such as contagion from one individual to another, it is in fact Allah who is pulling the strings. Thus, we read in the Hadith:

Allah's Apostle said, “There is no contagion, nor jaundice, nor vermin [without Allah’s permission]” A Bedouin stood up and said, "Then what about my camels? They are [as healthy as] deer on the sand, but when a mangy camel comes and mixes with them, they all get infected with mange." The Prophet said, "Then who conveyed the (mange) disease to the first one?" (Sahih Bukhari, Volume 7, Book 71, Number 615)

Disease strikes according to Allah’s plan, which, although it may not seem like it, is benevolent, and should not, therefore, be opposed:

Narrated 'Aisha: (the wife of the Prophet) that she asked Allah's Apostle about plague, and Allah's Apostle informed her saying, "Plague was a punishment which Allah used to send on whom He wished, but Allah made it a blessing for the believers. None (among the believers) remains patient in a land in which plague has broken out and considers that nothing will befall him except what Allah has ordained for him, but that Allah will grant him a reward similar to that of a martyr." (Sahih Bukhari, Volume 7, Book 71, Number 630)

There are two aspects of this I want to emphasize: the seemingly odd notion that plague can be a "blessing," and the last part, the part that says “Allah will grant him a reward similar to that of a martyr,” I can’t underscore its significance enough. It puts a believer who is killed by plague in the same category as a jihadi who is killed in a holy war: they both automatically go to heaven. Another hadith makes this explicit:

The martyrs are of five kinds: one who dies of plague; one who dies of diarrhea (or cholera) ; one who is drowned; one who is buried under debris and one who dies fighting in the way of Allah (Sahih Muslim Book 020, Number 4705).

The insistence that health and disease are entirely a matter of the Will of Allah doesn't preclude doing something about it. The same paradox that exists about other areas of life applies here as well. The book on medicine in Bukhari’s collection of Hadith contains accounts of Muhammad recommending all sorts of antidotes and treatments: dates, cupping, caraway seeds, camel urine, honey (for stomach ailments), talbina (a porridge of barley, milk, and honey), truffle water (for diseases of the eye), incense (inhaled like snuff for tonsillitis and pleurisy), and ruqya (exorcism—for snakebite and scorpion sting). The only treatments he explicitly opposes are cauterization and relieving tonsil pain in children by pressing on the palate with your fingers.

In one hadith, quoted by Ghazali, Muhammad is challenged point blank about the apparent contradiction: “The Prophet was asked about medicines and spells and enchantments: Can they annul the decree God?” Muhammad’s way out: “It is also God's decree.”

We have an early case study on how this paradoxical view of destiny and agency plays out in practice during the reign of the caliph Omar (634-644). Omar had been a Companion of Muhammad and it was during his caliphate that Muslim armies fanned out across the Middle East on a campaign of conquest. In the year 638 or 639, the Plague of Amwas (Emmaus) broke out. Readers of the New Testament will recognize the locale: it’s the village near Jerusalem where Jesus appeared to his disciples after the resurrection. The uncertainty in the date of the plague might indicate there were two waves of infection, as was the case with the Spanish Flu of 1918 and, as some fear, may be the case with coronavirus. As for what kind of disease it was, the sources don’t say, but historians believe it was Bubonic Plague, an aftershock of the Plague of Justinian that ravaged the Byzantine Empire starting in 541.

Omar's dilemma was whether to leave his troops where they were or to withdraw them to safer ground. After travelling about the country, consulting various advisors, and suffering some miscommunications with the commander, Abu 'Ubaida bin Al-Jarrah—there was a whole rigmarole that I won't bore you with—he finally settled on withdrawal. A hadith tells us the decision subjected him to considerable criticism:

Abu 'Ubaida bin Al-Jarrah said (to 'Umar), "Are you running away from what Allah had ordained?" Omar said, "Would that someone else had said such a thing, O Abu 'Ubaida! Yes, we are running from what Allah had ordained to what Allah has ordained.

No matter which choice Omar made, what Allah ordained would prevail. Indeed, his decision to move the troops to safety did not prevent the plague from decimating the army. Twenty five thousand Muslims died, including Abu ‘Ubaida.

The hadith continues,

At that time 'Abdur-Rahman bin 'Auf, who had been absent because of some job, came and said, "I have some knowledge about this. I have heard Allah's Apostle saying, 'If you hear about it (an outbreak of plague) in a land, do not go to it; but if plague breaks out in a country where you are staying, do not run away from it.'” Omar thanked Allah and returned to Medina. (Sahih Bukhari, Volume 7, Book 71, Number 625)

Which brings us full circle to the hadith with which I started this post, and we can now revisit it within the framework of medieval Muslim theology. The reiteration of the hadith inside a broader narrative about Allah’s Will being carried out at Emmaus, regardless of what we impotent humans do, is a smoking gun, giving us context that wasn’t available in the shorter version I cited above. Other variations (Sahih Muslim Book 026 Number 5493-5499) are equally enlightening; they say explicitly that the reason one should neither go to a place that is plague-stricken, nor flee from one, is “It is a calamity or a disease which Allah sent to a group of the Children of Israel, or to the people who were before you.”

Clearly, as it was understood by the theologians of the time, the hadith is not about anticipating modern quarantine methods to prevent the spread of disease. Rather it is a command to be patient and acquiescent in the face of Allah’s plan. If Allah's plan is to punish you with plague for your sins, you cannot escape death by fleeing from it. If His plan is not to "bless" you with plague for your faith, you cannot achieve martyrdom by chasing after it. Either way, do not try to change the outcome. You cannot succeed.

NEXT UP—What the medieval Muslim scientists had to say. As we will see, it is equally rife with contradictions.

Michael Isenberg drinks bourbon and writes novels. His latest book, The Thread of Reason, is a murder mystery that takes place in Baghdad in the year 1092, and tells the story of the conflict between science and shari’ah in medieval Islam. It is available on Amazon.com Please follow Mike on Facebook and Twitter. Subscribe to Islam: the Good, the Bad, and the Everyday