Sick in the City


David Selim Sayers

Sick in the City

 Humans haven’t always lived in cities. And humans haven’t always had pandemics. In fact, a panoramic glance from prehistory to the present reveals that the two—urbanization and infectious disease—have flourished hand in hand. Why are cities so viral? If viral is what they have always been, why did people build them? Can we do something about them being viral—and should we? Finally, if we think that we should, who is the “we” that comes up with the plan, and who the “we” that carries it out? The pursuit of these intriguing questions may not lead us to definite answers, but the journey may prove more instructive than its destination.


MANY city-dwellers around the world have reacted to COVID-19 by deserting their urban habitats, some just for a while, others for good. It may seem redundant, then, to analyze the connection between urban life and infectious disease; after all, common sense seems quite able to work out this connection on its own, without any scholarly crutches. As long as the city is a healthy place to live, people flock to it; when it becomes unhealthy or unsafe, they leave.

But clearly, things are not that simple. First, no matter how unhealthy, dangerous, or claustrophobic the city becomes, a lot of people stay. Also, many who leave don’t leave for the open countryside, but for other cities—different kinds of cities, perhaps, but cities nonetheless. There is something about cities that prompts or compels us to place our very lives at risk for the sake of staying in them—although that something may not be the same for everyone. Disease isn’t going anywhere, but neither, it seems, is the city, so the tense relationship between the two is bound to persist.

A Note on Method

Before we go any deeper into the special relationship between sickness and the city, a few words on my approach. I don’t conduct empirical research on cities; I mostly work with literary sources to find out more about premodern urban culture, particularly in Constantinople under the Ottoman Empire. I also teach on cities, and as teachers know well, the vocation has a tendency to suck you out of the particular and into the general. So while I started out teaching specific courses on Constantinople, these eventually morphed into courses on urban history as a whole. All this is to say that my approach here is synthetic, standing on the shoulders of giants, looking out on contemporary issues, adding what I see from where I’m perched, and mixing it all together with my own humble two-plus-two.

My thoughts on the city would be pretty boring if not for the work of Douglas Massey, whose course on urban history I took on an educated whim, even though it had nothing to do with my trajectory as a PhD student in Near Eastern Studies. Massey’s passion in the classroom was so infectious, and the readings he assigned so inspiring, that it was quite a letdown when I finally read his own book on urbanization, Strangers in a Strange Land (2005). Here, he ditches the joyful, agnostic interdisciplinarity of his classroom work for a sterile, reductionist, and deterministic account of urban history packed with definitions, abstractions, causalities, and theories—no doubt in a valiant effort to prove that sociology is not some ignoble bastard son of history and statistics but an exact science worthy of university departments and generous endowments.1

Let’s take a minute to compare (somewhat ungenerously, I must concede) a passage from Massey with one from another source I know only thanks to Massey, Lewis Mumford’s The City in History (1961). Here is Massey:

Cities consist of large numbers of people concentrated at one place at one time, and the larger the number of people, the more ways they can be divided into meaningful social categories (Blau, 1977). The resulting social differentiation in human society increased the potential for heterogeneity (unranked differences among people on the basis of nominal classifications) and inequality (ordered classifications on the basis of hierarchically ranked categories). Agrarian urbanism thus brought about the first systematic stratification of human beings into classes defined by their differential access to material, emotional, and symbolic resources. For the first time, large, cohesive groups of people had conflicting material interests.2

And here is Mumford:

Yet the cold could not have been unendurable, or else people would have worn nightdresses or kept on a shift, instead of “going to their naked bed,” as numberless illustrations depict them. Privacy in bed came first in Italy among the upper classes: witness Carpaccio’s ‘Vision of St. Ursula,’ in a bedroom one would still find adequate and charming today. But the desire for it seems to have developed almost as slowly as the means. Michelangelo, on occasion, slept with his workmen, four to a bed. As late as the seventeenth century, maidservants often slept in trundle beds (rolled under the big bed by day) at the foot of their master and mistress, while three centuries earlier, Thomas Hoccleve refers in a poem to an earl, a countess, their governess, and their daughter all sleeping in the same room.3

Both passages work up to a similar theme, that of social stratification and its connection to urban living. But in Mumford, we find everything that Massey lacks: an authorial voice, opinion, contradiction, open-ended speculation, literature, the arts—in one word, life itself. One approach boards up the gates of inquiry with a litany of answers and certainties. The other invites us to join in an intellectual adventure, coaxing us to question the writer’s opinions, to check out paintings and poems, and to imagine ourselves in the place of flesh-and-blood people who lived centuries ago. Massey’s airtight logic may console our poor minds as they seek refuge in a semblance of order from the overwhelming chaos of human affairs. But it is only Mumford’s wide-eyed sense of wonder that can reconcile us with the unbridgeable gap between what we can apprehend and what we can comprehend.

Cities Are Viral

With this caveat in mind, let us return to our animating theme, namely the connection between sickness and the city. But we need to be careful here: imagining a “connection,” or, as I put it earlier, a “relationship” between sickness and the city could easily lead us to imagine sickness and the city as two discrete, separate facts that have nothing per se to do with each other, that exist independently of each other in their ideal states. The problem, then, would only arise when they come together due to some historical contingency. If so, we should be fine as long as we keep these two facts separate and discrete; prevent any contingency that may cause them to combine; and, just in case such a contingency slips through our preventive net, have measures in place to smother it as efficiently as possible.

If we base our inquiry on this understanding, every question we ask, every problem we propose for solution, will only lead us further astray. Why? Because sickness is not an unwelcome intruder into otherwise healthy city life, a temporary invader that must be kept at bay. Quite the opposite. By definition and design, cities are viral. Cities are meant to be viral. Cities would be of no use if they weren’t viral. Cities are petri dishes, places where purity is transcended and contamination is not only inevitable but intended. The power, productivity, and creativity that are cities’ raison d’être would never emerge if everything in them were pure, clean, and isolated. Cities suck in material from all kinds of origins, they assemble material that would otherwise probably never come into contact, and then they process, combine, exchange, and disseminate it.

This is the diversity, or heterogeneity, that Louis Wirth names as one of the three basic characteristics of urban life.4 It holds for inanimate matter, plants, animals, and humans. It holds for culinary recipes as much as for technological innovations, for ethnic groups as much as for religious doctrines, for philosophical ideas as much as for artistic movements. In effect, the city is a massive cocktail shaker designed to mix together different ingredients and see what comes out. There is no way to predict or control what comes out—that’s the whole point. Sometimes it’s a marketplace. Sometimes it’s an alphabet. Sometimes it’s a revolution. And sometimes it’s a germ.

Even if we leave aside diversity, there still remain Wirth’s two other urban sine qua nons, namely size and density. The sheer accumulation of more and more human beings in the same limited space is a reason in and of itself for the city’s existence. Massey has described the city as a “macrosocial computer” that works by combining the processing power of assembled individuals, harnessed according to specific rules and amplified by ever-improving means of transport and communication.5 My classroom may serve as a “microsocial” example of the same process: as a teacher, as long as I manage to keep an open mind rather than defensively playing the guardian of my own narrative, I keep learning things from my students that I would never have thought of alone, not necessarily because any one of them is more clever than me (though they may well be), but because many people together are simply quite likely to be more clever than a single person on her own.

The underlying process that makes the urban amplification of size, density, and diversity so potent, of course, is that of transmission. Cities are transmitters—perhaps the most effective transmitters we’ve ever devised.

Which brings us back to disease. A germ historian (if germs were ever to take up such a dubious vocation) might be forgiven for concluding that humans built cities just to facilitate germ evolution. In fact, by switching from nomadic to urban life, humans have enabled not just one, but countless great leaps forward in germ evolution that could never have occurred otherwise. The germs’ task is merely to spread among their human hosts at a potency and rate that does not drive the host extinct, or dissuade it from urban life. And at avoiding such a level of decimation among their human cattle, germs have, all in all, proven quite successful. As ever-new forms of infectious disease originated from urban populations, they enabled the now-infamous herd immunity, allowing these populations to coexist with them without being devastated by them.

But germs have done more to, or for, their human hosts than just force concessions of grudging coexistence from them. After all, coexistence needn’t be a zero-sum game, and who wants to be a parasite when you can be a symbiote instead? Symbiosis, however, requires that both sides gain from the bargain. Sure, germs gain by securing their transmission from generation to generation of hosts. But what do the hosts themselves have to gain, seeing as how not getting infected in the first place surely beats herd immunity? The answer, again, lies in transmission: the ability to pass on the germ to someone else, preferably someone with no prior exposure and therefore no immunity.6

The story was told perhaps most forcefully by Jared Diamond in his bestseller, Guns, Germs, and Steel: as European forces set out to colonize the Americas, their most potent weapons against native populations were the home-grown germs they brought along from the “old continent.” As much as 95% of Native American populations were wiped out by European germs without the need to ever use physical force against them.7 This may have happened unwittingly—or quite wittingly indeed, as in the case of Lord Jeffery Amherst who, in 1864, advocated the distribution of smallpox-infected blankets among Native American populations in the Great Lakes region in order to “Extirpate this Execrable Race,” since “Hunting them Down by Dogs” seemed impracticable.8 The question of intent, however, is somewhat moot as the results speak for themselves: the winners and losers of the American germ explosion are plain to see in the continents’ demographics today.

In the long run, the question may be similarly moot whether, as some claim today, parties associated with the People’s Republic of China produced, concealed, and/or disseminated COVID-19 with the intent of spreading it to “the West.” Again, the results speak for themselves: not only was 2020 the first year in which China overtook the US as the world’s number one country for foreign investment,9 among other economic metrics, but it was also the year that most forcefully proved, perhaps since the invasion of the Americas, that urban populations who know how to live with germs—and states that know how to deal with them—can make history swing their way, eclipsing others that have remained in a state of witting or unwitting ignorance.

Belly of the Beast

Cities were always death traps, from their first establishment in the Fertile Crescent around 10,000 years ago until way into the 20th century. Herd immunity notwithstanding, the germs produced in cities ensured that urban populations died off more quickly than they reproduced, which put cities on permanent life support, hooked on an external human drip without which they would have quickly died out. I am reminded of Metropolis, Fritz Lang’s 1927 masterpiece in which a vision reveals an urban factory as Moloch, a demonic deity that demands constant human sacrifice in order to sustain itself.10 And though Lang’s Moloch stood for industrialization rather than urbanization, it is easy to imagine the city itself as the man-eating monster god.11

Nor was pre-urban life so wretched that anyone would have braved the jaws of Moloch just to escape it. Foragers actually enjoyed significantly better health than early city-dwellers. They lived longer. They ate better. They were taller. Fewer of their children died. They weren’t beset by infectious disease. And, as Marshall Sahlins has taught us, health was not the only argument that favored the foraging lifestyle. Since foragers were always on the move, they had no possessions that could slow them down. Since they had no possessions, they had no private wealth. Since they had no private wealth, they had no structural inequality. Since their only real work was to secure food, and they only secured as much as they ate, they had plenty of free time. And since infant mortality didn’t condemn women to constant childbirth, both sexes played a comparable role in communal life.12

Ah, but nothing good ever comes easy, and everything has its price. Without the city, after all, we wouldn’t have the sum total of human material and cultural achievement that we proudly call civilization, derived from civitas, Latin for city or citizenship. Let’s say, then, that in a quest for civilization, in a noble quest—perhaps even a somehow natural, genetically preprogrammed quest—for loftier cultural and material heights, we as humans resolved to build our own Molochs, accepting the hazards of city life as a necessary evil, grimly determined to deal with them as they arose along the way.

Or let’s not. Instead, let’s look at what I just said and see if it makes any sense at all. Let’s start with the word “we.” “We” resolved to build our own Molochs. “We” accepted the hazards of city life. Except, of course, “we” didn’t. None of us was around as these epochal changes took place over the course of millennia. No written record speaks of these prehistoric times, prehistoric as in predating history, predating history as in predating the time humans began to write their own history. So whatever “we” presume about the motivations of these prehistoric people is just that—our own presumption. Note that I am not talking about facts—of which there are, if anything, too many—but motivations, the closest thing to causal connections we have in human affairs. Without motivations, as Hayden White reminds us, there is no history; just a meaningless chronology of facts. But motivations, as we ascribe them to others (or even ourselves), must always be fictional.13 “We” would do well to remember this Siamese bond between history and fiction—history and story—revealed by the ambiguity of the French histoire.14

“We” is a dangerous pronoun. Perhaps even more so than “I,” it evokes something that doesn’t exist, a unity of units that only form a cohesive whole in the speaker’s imagination or by the speaker’s will.15 It is dangerous enough when applied to conglomerations of living human beings, but particularly insidious when stretched out to include the dead. Surely, it must be a universal human weakness to imbue long-dead people with motivations based on how we would like their actions to relate to our own self-image. And since we—or at least that part of “we” likely to come across this essay—are by and large quite pleased with urban life, it is easy for us to imbue our prehistoric ancestors with an instinctive desire for that which we cherish today.

This, so I am told, is what smart people call teleology. Teleology is the confusion of an outcome for a goal (telos in Greek). It underlies such fascinating thought experiments as the “fine-tuned universe.” The balance of elements and forces in the universe, it is said, is so fine-tuned that even the slightest deviation would make human life impossible. And among all the possible balances, ours is so improbable that it can only have been brought about by an intelligent creator. This theory works beautifully—but only, of course, as long as you assume that human beings were the intended goal from the beginning. It loses all meaning if you assume instead that human beings are as accidental an outcome of the universal “balance” as a floating piece of astral dust.

The same goes for urbanization. Prehistoric evidence holds nothing to confirm that “we,” many thousands of years ago, developed a mystical or genetic prescience of hot showers or take-away pizza, embarking on a heroic journey across the millennia to attain such lofty goals. The question, then, about why exactly human beings would become urbanized in the first place remains fascinatingly open.

Let’s try approaching the why by way of the how. The how, as every student of human history knows, is agriculture. Agriculture enabled humans to produce and store more food than needed for daily sustenance. But there were consequences. First, to make and store the food, you had to stay put. Second, not everyone who ate the food had to make the food anymore. Third, once you stored the food, it was no longer just food—it was property.

So let’s say I’m an able-bodied human in an agricultural setting who, by some contrivance, can stay fed without making food. Now, If I could gather a large enough group of other able-bodied humans who weren’t making food, we could simply go from place to place and take as much food as we needed. We wouldn’t just take the food, of course. We’d offer something in return—protection. Protection against other roaming groups of able-bodied humans—bad humans, not like us—who might come and take the food—all the food, not just a reasonable tax like us.16 The more food we collected, the more people our group could sustain. And the larger our group became, the better services we could provide for those who make the food. We could build weapons to better protect them. We could make roads to reach them more quickly. We could conquer more fields for them to till. And we could worship the gods who blessed them with our guidance.

But in order to do all this—to store our food, to keep our records, to make our weapons, to gather our forces, to worship our gods—we’d need a place. A well-protected place. Walls would be nice, with guarded gates. Quarters for our warriors, our artisans, our scribes. A center to put the market, and the temple, and a nice dwelling for our leader, to represent our fortune and might. And so what if this place—okay, let’s call it a city—turned out to make people sick? If the people we needed there refused to come for fear of disease, fear of our weapons would surely change their minds. As for those pesky foragers who still rejected civilization—well, our germs would take care of them.

I have no doubt there were people who chose to come to the first cities, drawn like moths to the flame of sheer power they radiated. But there is no reason not to assume that many others, perhaps a majority of others, were brought to the city by force, like the human sacrifice led to the mouth of Moloch in Metropolis. History, if not prehistory, offers plenty of examples; I will restrain myself to one: when Mehmed II, ruler of the Ottomans, conquered Constantinople in 1453, he was faced with the daunting task of repopulating the nearly deserted city as his new capital. When incentives such as tax breaks and free housing failed to yield the desired result, he resorted to forced deportation, resettling the quarters of Constantinople with a variety of vocational, regional, and religious groups from across his realm. The germs were not far behind: a mere fourteen years after the conquest, the city was devastated by an outbreak of the plague that claimed up to one third of its rustic, reluctant, and nonresistant population.17

Now That We’re All Here

Today, with the majority of the world’s population living in cities and more people flocking to them by the minute, it is hard to imagine that the great leap forward from foraging to urban life was driven by physical coercion rather than free will or some kind of inevitable evolutionary drive. But even today, many who migrate to cities are anything but free in their choice. Industrialization has made local work seem redundant while globalization has dismantled small-scale, self-sustaining economies. To stick to my area of study, the rise of megacities in Turkey only occurred after the Second World War, when the country’s gradual integration into the capitalist world economy meant that regional, state-run factories, built not for profit but for local employment, were shut down and replaced by private factories which, for reasons of efficiency, started springing up around urban centers such as Istanbul and Ankara. Driven this time not by imperial decree but by sheer economic hardship, the population of Istanbul skyrocketed from around 1 million in 1950 to almost 20 million—a quarter of Turkey’s entire population—today.

Finally, the city exerts its draw not just through the hard power of physical or economic coercion, but also through the soft power of culture. Who among us has not, at an impressionable young age, been exposed to countless songs, films, stories, ads, and other cultural products that have taught us the city as the only place to be, the only place where the complete human experience can be had, and have held up the city-dweller as the embodiment of sophistication and grace, the model to which the rest of the population must grudgingly aspire if it is not to be branded as bumpkins, rednecks, or whatever choice insult the national language has in store for its not-quite-citizens?

All these coercive factors—physical, economic, cultural—are the means by which the city acquires dominion over its hinterland, over the vast lands and populations from which it draws constant sustenance. Some form of inequality may well have existed even before urban life. But the exploitative relationship between city and hinterland only confirms Massey’s assertion that cities are the most ancient and magnificent tool humankind has created for the establishment, implementation, and institutionalization of inequality on a social scale.

Is there a tipping point? Many supporters of Brexit in the UK or the Le Pen dynasty in France claim their countries are being overrun by foreign multitudes that drain the nation of its resources. Mentioned somewhat less is that these multitudes would not exist—whether in reality or in the nationalist imagination—if colonial Britain and France hadn’t so utterly drained their homelands of the resources needed to get by at home. In the case of the city, the multitudes are all too real. Over a billion people now live in urban slums,18 and as the great unwashed camp out right in their back yards, urban power brokers may be asking themselves whether the hinterland needed to be drained of its resources quite so ruthlessly. But a city has no borders to close, and in any case, we’re all already inside—needed or not, welcome or not, and whether the city can sustain our presence or not.

The germs, of course, are still with us. The death trap has been broken thanks to scientific advances such as germ theory, and cities now grow from within as well as without. But diseases such as COVID-19 continue to thrive on the systemic inequality hard-wired into urbanized society: from the Amazon to the Bronx spread the ghettos of disadvantage in which escape from sickness becomes a minor miracle. And as modern transport amplifies the role of cities as population concentrators and distributors, local diseases grow into pandemics that tear through the whole world in mere months.

If you have read this far, you may well have reached the conclusion that I am advocating for the abandonment of urban life altogether, perhaps even a return to nomadic foraging lifestyles. And as much as the anarchist in me would like to defend exactly that, I cannot ignore the fact that I myself am a hardened urbanite who has loved and lived in some of the most storied megacities of the world, from Paris to Shanghai, from Istanbul to New York City. I do not truly believe we could or should get rid of the city altogether. But I do believe we need a sober reckoning of what the city is and what it is for, a level-headed assessment of the city’s basic functions and the tension between them, namely the amplification of diversity, productivity, and creativity on the one hand, and the concentration of power and inequality on the other. And we need to ask ourselves how best to balance these inherent functions of the city.

This brings me to the elephant in the room, the one I squeezed in when I started resorting to the same “we” that I’d been at such pains to debunk earlier on. Who is this “we” that ostensibly questions what cities are, how to make them viable, and how to govern them? Is it “We the People” as represented by, well, representative governments in the “West”? The flailing reaction of these to COVID-19 only reminds us not to seek vision from power holders whose event horizons are the next voters’ poll and quarterly report. The best such a “we” can do—as forcefully argued by my friend and colleague Kristof K.P. Vanhoutte—is to lock “us” down in a perpetual state of limbo while lulling our minds with tall tales about the end of history.19

But elsewhere, history marches on. In the People’s Republic of China, where the state has sufficient economic, political, and institutional power to fend off short-term and special interests, cities of millions were placed under complete lockdown until active government policies had eradicated the virus and the life of an incomprehensible 1.5 billion people could continue as before. In Switzerland, with its township-based direct democracy, a mere 86,000 voters were enough to trigger a referendum that could strip the state of its special pandemic powers, such as the power to order lockdowns, altogether.20 And if “our” representative governments offer neither the direction of the former nor the liberation of the latter, at the very least, in their utter dereliction, they offer a chance to question where the “we” we seek might be found.


DAVID SELIM SAYERS is a co-founder and core faculty member of the Paris Institute for Critical Thinking (PICT). He teaches and writes on cultural history, particularly in relation to the Ottoman Empire and Turkey. His books include The Struggle For Modern Turkey (Bloomsbury, 2019) and The Wiles of Women as a Literary Genre (Harrassowitz, 2019).

dePICTions volume 1 (2021): Pandemic Times

1. As Philip Alcabes points out in his exquisite contribution to this volume, “Coronavirus, Epidemiology, and the Myth of the Primacy of Will over Matter,” dePICTions 1 (2021), “Valorizing the quantifiable result as the key indicator of reality is a leaky process. It tends to spread.”
2. Douglas Massey, Strangers in a Strange Land: Humans in an Urbanizing World, New York: Norton, 2005, 111-112.
3. Lewis Mumford, The City in History: Its Origins, Its Transformations, and Its Prospects, New York: Harvest, 1961, 286.
4. Louis Wirth, “Urbanism as a Way of Life,” The American Journal of Sociology, 42:1 (1938), 1-24.
5. Massey, Strangers in a Strange Land, 118.
6. Having had the pleasure of perusing my co-editor Carlo Salzani’s contribution to this volume, “COVID-19 and State of Exception: Medicine, Politics, and the Epidemic State,” dePICTions 1 (2021), I would add a much more insidious “symbiotic” feature of germs, namely the pretext they bestow upon political power holders to discipline their populations.
7. Jared Diamond, Guns, Germs, and Steel: The Fates of Human Societies, New York: Norton, 1997. Diamond’s account of European germ impact on Native American populations can also be found in “The Story Of… Smallpox – and other Deadly Eurasian Germs,” PBS [26 February 2021].
8. Peter d’Errico, “Jeffery Amherst and Smallpox Blankets” [26 February 2021]. The notorious Amherst was brought to my attention by Michael Barry in “Our Own Endemic Madness,” The Faculty Lounge, 23 January 2021 [26 February 2021].
9. For instance, Sarah Hansen, “China Passes U.S. As No. 1 Destination For Foreign Investment As Coronavirus Upends Global Economy,” Forbes, 24 January 2021 [26 February 2021].
10. Fritz Lang, Metropolis, UFA, 1927, film.
11. Again, following my reading of Salzani’s “COVID-19 and State of Exception,” I cannot resist the temptation to draw a parallel between Moloch and Leviathan, especially since, as Salzani points out, the frontispiece of Thomas Hobbes’ Leviathan combines imagery of the city and the plague.
12. As so many who came before me, I was educated as to the comforts of foraging life by Marshall Sahlins’ extraordinary essay, “The Original Affluent Society,” collected in his Stone Age Economics, London: Routledge, 1972, 1-41.
13. For White’s ruminations on history and fiction, you could start with his essay collection, Tropics of Discourse, Baltimore: Johns Hopkins University Press, 1978.
14. Alongside, of course, so many other (non-Anglophone) languages, including Italian, Spanish, and Portuguese, but also German.
15. For a classic discussion of how nationalism constructs this “we,” see Benedict Anderson’s Imagined Communities, London: Verso, 1983.
16. The argument that we should view the state as a protection racket—albeit a fantastically successful one—has perhaps been made most forcefully by Charles Tilly in his classic article, “War Making and State Making as Organized Crime,” published in Bringing the State Back In, ed. Peter Evans et al., Cambridge: Cambridge University Press, 1985, 169-191.
17. Nükhet Varlık, “Plague epidemics in the post-Black Death Mediterranean and the Ottoman Empire,” ehistory, 6 April 2012 [26 February 2021].
18. United Nations Population Fund, State of World Population 2007, New York: United Nations Population Fund, 2007, 16 [26 February 2021]. I am thankful to my student Camille Tocqueboeuf for bringing this statistic to my attention.
19. See Kristof K.P. Vanhoutte, Limbo Reapplied: On Living in Perennial Crisis and the Immanent Afterlife, London: Palgrave Macmillan, 2018, and also Vanhoutte’s contribution to this volume, “The Gentle Art of Making ‘Un-Decisions,’” dePICTions 1 (2021).
20. For instance, Thomas Colson, “Switzerland is holding a referendum on whether to strip the government of its power to impose coronavirus lockdowns,” Business Insider, 14 January 2021 [26 February 2021].