The man across the aisle on the flight home spent thousands of dollars on a European vacation with his family. While killing time in the airport, he unloaded almost all of what was left of his euros—the big notes—on duty-free souvenirs for friends. Now, as the plane begins its descent, he tosses his pocket change into a fund for African children.

The airline launched the charity collection a few years ago, as part of the widespread drive for so-called corporate social responsibility. You have a bout of nausea as you watch the flight attendants collect the donations. What’s revolting is not so much the program itself; as the announcement on the PA earnestly insists, “Change adds up”—which, though a vile piece of marketing, is true enough. Rather, it’s the ritual you have witnessed, with artificial gratitude on one side of the transaction and a passing moment of self-satisfaction on the other.

But then, you are on the same flight. You have also donated your loose change to the cause and perhaps a bill, even a large one, and have shed with it a bit of the complacency that comes with enjoying a world of wealth and privilege. The plane taxis to the gate, and, after clearing customs, you get on with your life. The limo to Manhattan from JFK comes to $100, tip included.

That such a life—a uniquely fortunate one in the annals of history—is essentially unearned in a world of horrors is a truth that our culture keeps at bay most of the time. But disquiet about it erupts all the same, in some people more than others. What if you were so often troubled by the incongruity between your sense of material comfort and the destitution of others, or unable to find routine defenses against it, that you felt you had to change your life entirely?

“It was never a new idea that people are selfish,” Larissa MacFarquhar observes in one of the lapidary aphorisms scattered throughout Strangers Drowning, her masterpiece of a book about those among us who decide to drop everything and become extreme altruists. Is their “impossible idealism” a genuine alternative to our self-­involvement and smug advantage, abetted by a showy generosity that is all the more grating for being deeply inadequate? More important, who are these saintly few who, refusing to tolerate worries about complacency and complicity, set out to change or even save a life a hundred or a thousand miles away? Their “inhumanly lofty” benevolence sharpens our inevitable but passing doubts about our unprecedented entitlement. It pushes our fleeting outrage or rational condemnation of things as they are into an extreme and perhaps extremist ethic, transforming what might be supererogatory duties—things that might be done for extra credit—into necessary, if not militant, demands.

What is most arresting, and troubling, to MacFarquhar about extreme altruists is that, unlike most people, they rank the needs of perfect strangers with those of their own families and friends. An African child can suffer as much as my mother—or me; no one is more or less human than anyone else; foreigners in pain around the world outnumber even the widest group of one individual’s acquaintances, especially for anyone living in a rich nation. MacFarquhar’s do-gooders, by turning the ephemeral fancy of being ethi­cally upright into a whole way of life, substitute a kind of impersonality for the overwhelmingly personal moral relationships that even the most generous people favor.

* * *

MacFarquhar herself is intensely interested in the people she gets to know. A New Yorker staff writer renowned for her luminous profiles of the famous and the anonymous (some of which have been successfully folded into this book), she is one of the most tal­ented nonfiction writers working today. Most of Strangers Drowning consists of profiles of do-gooders, which are its beating heart and the greatest evidence of MacFarquhar’s extraordinary gifts. “Only actual lives,” she says, “convey fully and in a visceral way the beauty and cost of a certain kind of moral existence.” Interleaved among her case studies are more reflective chapters, including a series on possible objections to the single-minded exigency of these do-gooders.

MacFarquhar describes her cast of characters with a kind of sympathetic neutrality, like the ethnographer of a tribe that most of us would never ditch our family and friends to join, but might find interesting or challenging nonetheless—perhaps because we too occasionally feel that our lives are empty or offtrack. MacFarquhar admits early on that she’s not sure whether the radical alternative posed by her “saints” to our ordinary balance of personal commitments is right or wrong; she only wants to investigate what has led to their commitments. Each one has a childhood and a coming of age as a saint; some have a crisis of faith; and a few fall from grace.

There is Dorothy Granada, who moves to Nicaragua in the 1980s to build a health clinic for women. She takes care of victims, whether or not they are part of the armed struggle occurring in the region, and regardless of whether they are Sandinista or Contra; she even has to go into hiding after she’s accused of helping the wrong people. Her husband, Charles Gray, spends his time proselytizing for a “World Equity Budget” that calls for each person to spend no more than $1,200 a year, a sum that reflects the overall global income at the time divided by the global population. The couple also undertakes a nearly fatal fast in response to the “Euromissile” debate of the era. There is Julia, who reads about the World Equity Budget and rejects it on the grounds that it is senseless to reduce personal spending if there’s no guarantee that the unspent money will go to those who need it most. She joins the “effective altruism” movement, which vets charities in the hope of making a difference, and struggles deeply with whether to have a child, on the grounds that it is a misallocation of resources.

As such vignettes suggest, MacFar­quhar is fascinated by the sheer extremity of those who, failing to moderate their need to be morally upright, deny themselves all but the bare minimum to survive, so as to give the rest of their income or possessions to others. At the very least, their actions exceed what most of us would see as adequate—for example, the man who gives one of his kidneys to someone he reads about online. These are almost inhuman examples of compassionate generosity and ascetic rigor—an ethos that could also have a chilling or off-putting effect for anyone with a less strenuous sense of the moral life. If failing to live up to their example is wrong, how many of us want to be right?

* * *

MacFarquhar also knows that in our day, a moral paragon is someone who goes to extreme lengths to save people far across the globe. The title of her book alludes to a question that the philosopher Peter Singer asked more than four decades ago to explain why people are morally obligated to do what they can to alleviate famine. If you passed a dying child, would you really not feel impelled to save her? If so, then why should the intermediation of long distances matter? Singer was spurred to make this argument by a civil war and a cyclone in Bangladesh (then East Pakistan). He preaches effective altruism today in some of his popular books, and his TED Talk on the subject long ago passed a million views.

MacFarquhar’s book begins with a scene in a restaurant in which a philosophy student who has clearly read Singer’s work is explaining to his professor—a family man—why the welfare of abstract humanity matters as much as that of his own children. MacFarquhar takes a long look at another young man who, already burning with idealism, reads Singer’s famous essay “Famine, Affluence, and Morality” and sets out to live frugally in order to bring his personal life into conformity with altruistic justice. To buy a can of soda, it might be argued, is to opt for killing a child far away—because absent that dollar spent on humanity, somebody somewhere will die. And once you know this, how could you spend that dollar on a can of soda for yourself? If the amount spent on luxuries for the 1 percent were redirected to Africa, how many more people would survive?

MacFarquhar invokes another philosopher, Susan Wolf, who refers to such people as “moral saints.” MacFarquhar claims that the skepticism of such moral extremists “has a history,” one around three centuries old. In fact, her view seems to be that a humanitarian devotion to one’s fellow beings was much more ethically plausible long ago, when religion dominated human life and there were literal saints and widespread cults of sainthood. She says as much in a passing remark about Singer’s conclusion that most people are, in effect, constantly perpetrating massive crimes by preferring their own comforts or their family’s wants and thereby spurning “the life you can save” (the title of one of Singer’s books). This may seem the hectoring of a bizarre malcontent, MacFarquhar acknowledges, even though, “in the past…the idea that nearly everybody was a wretched sinner seemed perfectly normal.” For contemporary do-gooders, she continues, life is always an emergency situation, much like wartime. But whereas war was once a much more participatory and widely shared experience because of conscription and privation, she concludes, our time demands less self-sacrifice in general, “which may be one reason do-gooders look even odder now than they used to.”

But the rise of figures with an extreme devotion to the remediation of distant suffering also has a history. Religion was never mainly concerned with establishing a morality fixated on the pain of others. In the monotheistic religions, most of one’s duties were to God, not to one’s fellow creatures; the golden age of sincere moralizing about philanthropic duties came about only in the 19th century, not before. If war was once a regular part of human experience, the appearance of humanitarians who treat the remediation of suffering as if it were a personal war—or even its moral equivalent, in William James’s phrase—is a much more recent phenomenon.

Then too, Christian saints were rarely canonized because they wanted to rid the world of suffering. Many were models of fidelity in the face of persecution; some were “extremists” only in their devotion to contemplation and prayer. If some of them helped the poor, it was often to illustrate how to seek God’s grace. Humanitarians may be likened to saints, but the comparison is inapt, because what the saints exemplified was never primarily an identification with the travails of others, let alone some vision of global justice.

It is true that identifying with suffering—but mostly with that of God’s human incarnation—has been seen as part and parcel of Christianity. And a modicum of charity has long been a component of organized religion. Faith has also provided reconciliation with the endurance of suffering: Pain was sometimes consensual and indeed valuable. Monks lacerated their flesh, while some female saints starved themselves in “holy fast” (which was not undertaken out of charity for others). For aristocrats, ritualized dueling and military service had an innate nobility, while the common folk viewed human and animal pain as sport. That Mother Teresa springs to mind when someone says the word “saint” is far more a consequence of a generally secular revolution in moral standards than its cause.

Today’s purists do not violate their flesh in monasteries; they heal the bodies of others beyond our borders. And while there are contemporary icons famous for giving alms, MacFarquhar is interested in those founding humanitarian NGOs. This matters because she has written a study not just of moral extremism in general, but also of why such behavior is appealing and repellent in a secular ethical universe transformed by mass humanitarianism. It has been only in the last few centuries—the same period during which skepticism arose as a response—that our culture has been unique in making “saints” of those who feel the pain and torments of strangers around the world. At best, the “saintliness” of MacFarquhar’s humanitarians is a metaphor that captures how extremism and rigor are applied to prevailing values.

* * *

In the 18th century, a new kind of person appeared: the “man of feeling,” moved to pity by the spectacle of misery. And it was a startling departure: The great literary historian R.S. Crane called the modern ethic “something new in the world—a doctrine…which a hundred years before 1750 would have been frowned upon, had it ever been presented to them, by representatives of every school of ethical or religious thought.” Soon there were women of feeling too; and sentimentalism, as the movement came to be known, was often understood by its proponents (and detractors) as feminizing the world and making men sensitive, as women were stereotypically thought to be. “Moral weeping is the sign of so noble a passion, that it may be questioned whether those are properly men, who never weep upon any occasion,” one sentimentalist insisted in 1755.

The mainstream media of the time remained shot through with religion and tradition, but because of faster travel and the rise of newspapers, the man of feeling was able to read about the pain of others over long distances, creating the foundation of the modern humanitarian ethic. Enlightenment thinkers like David Hume and Adam Smith worried that humans needed help imagining distant suffering, because most people only cared about pain that can be seen. In ordinary circumstances, the shattering of a mirror in the next room can elicit more grief than a deadly fire far away, Hume observed. But the new telescopic journalism—by making faraway suffering locally vivid—went a long way toward closing that gap. Empathy toward distant strangers is not absolutely essential to extreme altruism. You could swoop in to help a stranger in your apartment complex, should tragedy befall her; MacFar­quhar writes of a kidney donor helping a woman across town. That she treats distance as central is a telltale clue to how closely correlated the rise of do-gooders was to the global perspective bred by new media.

MacFarquhar rightly observes that great devotion to the cause of relieving faraway suffering no longer depends on people feeling compassion. She discusses the Enlightenment philosopher Immanuel Kant, who, though inspired by sentimentalism, worried that duty couldn’t be grounded in something as evanescent, unreliable, and unevenly distributed as sympathy for others. But as MacFarquhar also observes, often the most coldly rational calls for justice conceal deep wells of emotional affect. On seeing the student in the restaurant moved to tears at the thought of the people who perished in catastrophes hundreds of years ago, even though they are beyond anyone’s help, she remarks: “What appears at first to be an absence of emotion then appears to be a need to control overwhelming emotion that is apt to surface without warning.” Grounding a duty to humanity in reason makes philosophical sense, but for many of its partisans, reason also functions as a justification for something more primal.

* * *

Moral extremists are sometimes seen as closet narcissists, MacFar­quhar observes, or as “codependent” with their beneficiaries in ways that border on pathology (she makes an illuminating parallel with alcoholism and the recovery from it). But she is especially taken with one criticism of extreme altruism, and skirts another almost entirely.

“If there is one place more than any other where do-gooders are set up as enemies of humanness,” MacFarquhar writes, “it is in fiction, particularly modern novels.” This is because novelists would rather portray the inevitability of human imperfection than embark on a quixotic attempt to end it, she argues. But novelists have often also written in defense of multiple commitments, justifying the plural and the messy against the monomania and rigor not just of moral extremists, but of an exclusively moral stance on life in general.

In a particularly insightful passage, she dwells on George Bernard Shaw and Leo Tolstoy, who exchanged art for humanitarianism and then indicted art’s complacency. Both writers bitterly attacked Shakespeare for portraying human frailty so generously—almost novelistically—without proposing to mend it. After his conversion to Christianity, Tolstoy went so far as to rank Harriet Beecher Stowe’s Uncle Tom’s Cabin above the Bard’s plays, because Stowe had transformed art into humanitarian propaganda to spectacular effect. In response to such heresies, MacFar­quhar cites James Baldwin arguing that the price of Tolstoy’s transformation was grave: “The wet eyes of the sentimentalist betray his aversion to experience, his fear of life, his arid heart.” And, let’s not forget, his love of bad art.

MacFarquhar also draws on novelists, along with the late English philosopher Bernard Williams, to criticize rigorous altruism in a different way. Extremism in morality threatens not only morality itself, but a range of other concerns. We are not just moral beings, after all. “Morality likes to make it seem as though outside its kingdom of duty there is only meaningless, selfish impulse,” MacFarquhar writes, “but this is not true.… If a person is at every moment required to be attending to his moral duty, then much of what makes life worth living, and people worth loving, will have to be abandoned.” If full-bodied experience is what makes life valuable in the first place, then prioritizing rescue could become self-defeating. It could focus our culture so intently on saving bare life as to marginalize living well.

At times, MacFarquhar can sound like a novelist herself. In a symposium on Peter Singer’s effective altruism in a recent issue of Boston Review, her response to Singer’s proposals is more direct than the neutral profile she offers of him in her book. Singer’s movement, she says, is “the drone program of altruism,” in the sense that it tries to save lives from a clean distance, much in the way that the American military now kills most of its enemies. For all of the arguments in favor of saving or taking these lives, operations conducted from a safe distance on behalf of essentially anonymous strangers seem “off-putting,” she remarks. As in her book, she is absorbed by a moral extremism that the devotion to strangers makes especially graphic, and that seems to take ordinary commitments to their logical conclusions. But because it must interfere with other ordinary commitments—such as devotion to friends, family, and intimates, even if they are not suffering—the extremism risks “crushing” our “moral roots.” (In his response, Singer is unmoved by her suggestion of a paradox.)

MacFarquhar ends up fascinated by humanitarian sainthood but unsure about its claims. Immediately after presenting the novelists’ wisdom, she turns to a case study of a woman named Stephanie, who revolts against her onetime moral extremism—moving in the opposite direction of Tolstoy. Previously convinced by Singer, Stephanie rejects his thinking and decides to pursue a multifaceted life that necessarily reduces morality to one commitment among others in a shifting constellation. She had once worked for GiveWell, an effective-altruism outfit, but found herself hampered by her partner’s even more grandiose hopes to save the world, which she felt belittled her. So she leaves him, having realized that her extremism and embarrassment over not doing even more were rooted in self-loathing. There­after, Stephanie “didn’t have a philosophical refutation of [Singer’s] argument, but she no longer believed that she had to have one.” MacFarquhar presents Stephanie’s evolution as one toward emotional maturity, and “its vertiginous uncertainty was the price of her freedom.”

* * *

Criticisms of extraordinary humanitarian devotion in the name of “ordinary life,” however, pale beside other attacks that indict it in the name of a different radicalism. The most acerbic critic of the man of feeling, as MacFarquhar briefly notes, was Friedrich Nietzsche, who thought that the humanitarian impulse swamped the quest for personal distinction. Nietzsche attacked the notion of philosophers defending mediocrities simply because they could suffer, seeking instead to preserve “aristocratic” greatness in a crowd shedding modern tears: “This overestimation of and predilection for pity on the part of modern philosophers is something new: hitherto philosophers have been at one as to the worthlessness of pity.”

Karl Marx didn’t exactly find pity worthless, but he was more (or differently) radical in response to the man of feeling. For Marx, the character of one’s personal devotion didn’t matter much, and he had little patience for the psychology and paradoxes of altruism; instead, he asserted, justice is necessarily institutional. If change you can believe in occurs because of systemic reform (or revolution), the only interesting thing about somebody’s everyday or extreme altruism is whether it contributes to that larger project.

Marx wasn’t the only critic advancing such notions, of course, but he was notable in arguing for an institutional rather than an individual focus so early and taking it so far. By concentrating mainly on contemporary moral philosophers who know little, and care less, about politics and institutions, Mac­Farquhar skirts the fact that the institutional problem has become the essential one across the board, as outstanding recent books about humanitarianism by Alex de Waal and Jennifer Rubenstein argue. Such analysts take the next step beyond effective altruism, which remains stuck in a philanthropic model without challenging hierarchy or focusing on what kind of state and interstate institutions bring about actual change. The most telling responses to Singer, for example, indict his individualization of justice, as if wrongdoing were primarily to be remedied one donor at a time. In a laudatory preface to a new pamphlet version of Singer’s essay, to be published in December, Bill and Melinda Gates celebrate it for teaching that “we can work together to prevent very bad things from happening.” But do “we” work together through philanthropy or politics?

MacFarquhar doesn’t focus on this question. She describes one extremist as moving from trying “to help one person” to trying “to change the whole world.” But aside from a few pages on foreign aid, she doesn’t explore the implications of her passing comment that many observers have concluded along the way “that organized politics was a more effective vehicle for human progress than the full hearts of the leisured bourgeois.” Institutionalists might respond, for this very reason, that perhaps singling out the tourist in business class and his potentially inconvenient awareness of justice is more of a problem than a solution.

MacFarquhar’s stories are not directly about suffering and how it could ever end on its own, with or without our help; they are about our private dilemmas over that suffering and how they make us feel. If MacFar- quhar were living in an age of widespread faith in God, it would be permissible to stop there. But in an age of humanitarian faith, it is this world and the concrete results within it that count. Martin Luther criticized the medieval church, yet he never claimed to offer an unerring path to salvation. But when moderns criticize their institutions, it is often because they insist that the imperfect world is the only one we have—and so we must seek the best institutions to take caring beyond hypocrisy and self-doubt.

Perhaps because many people think that organized politics is a rickety vehicle for progress—and because it’s more typically seen as a recipe for the human tragedies that humanitarian sentiment is meant to palliate—­MacFarquhar is thrown back in her brilliant book on the alternatives of everyday versus extreme personal morality. She risks turning the effort of heeding the pain of others into a psychological or spiritual burden for those who must then choose between uncomfortably tolerating the mix of their commitments or abandoning them for monomaniacal sainthood. It’s a tough choice, and as with similar quandaries, the best response may be to create other options.