As I read Corrigan's book over the last few months, I encountered it on several occasions with an acute sense of displacement. The margins of my copy are filled with notes reflecting the strange feelings that come from reading a book about emptiness on the #1 train between 225th Street and 66th Street in New York. Each day, as my fellow subway riders and I jam aboard the increasingly-crowded train, we struggle to settle ourselves in acceptable spots; eventually and inevitably this means our bodies find an uneasy peace in a space directly touching those alongside us—legs bumping legs, shoulders touching shoulders, arms along arms. At some points along the journey, this fragile détente of human bodies is prone to crumble; would-be riders barrel aboard, leveraging themselves inside despite slamming subway doors, loud indecipherable admonitions over the P.A., and the muttered protests of those already occupying some portion of the space the newcomers need. For a few weeks I took this trip with Emptiness in tow and I marveled, huddling in my designated square feet and leaning over the book on my lap, as the men, women, and children of New York's west side struggled to find just enough emptiness to enable them to get to work.

There is more than uncanniness and dissonance in the phenomenon of reading a book about emptiness on a painfully full train. For Corrigan's book is not just about emptiness, it is really and more properly about the dialectic of emptiness and fullness as each of these different feelings (and particularly the relations between them) help to mold personal sensibilities and social relations. Feelings of fullness and emptiness go together: fullness prompts worries about saturation, emptiness is itself a longing for fulfillment. In the case I am pondering, the fullness of the train serves as a prompt to feelings of personal emptiness: it is easy to feel small, unjustly put upon, or even invisible in situations like that. These feelings are aptly summarized with the telling and vivid expression: “I've been crowded out.” Such feelings, which Corrigan's book would encourage us to gather under the rubric of “emptiness,” can also reach a breaking point. It does not take long for a subway rider to encounter shouting matches and even name-calling as new riders try to encourage established passengers to make room. Without fail, these incidents seem to capture the attention of the whole train car; it is as if we cannot pull our eyes away as the absurdity of our collective situation is made manifest in the hurtful words of two among us who have had enough.

The brilliance of this book is that it takes intense (if short-lived) existential realities like those, and turns them into the material for a new history, not just of American Christianity, but of the US itself. Emptiness makes the dialectical relationship between feelings of emptiness and fullness into a crucial driver of history. Christianity has been a key instigator of these feelings as well as a crucial interpretive lens for making sense of them. Americans inherited various ways of enacting or promoting kenosis—the Christian idea of the emptying out of self in “expectation of being filled by God”Footnote ⁸—from their protestant and Catholic forbears in Europe and Latin America. Being a good Christian meant being in some sense empty so that there would be room for God. Thus Americans disciplined their bodies and minds, designed their buildings, and imagined their landscapes and histories to reflect or encourage the pursuit of a purifying and potentially holy condition of emptiness.

The problem Corrigan discerns in all of this is that emptiness makes enemies. The more we valorize, pursue, and endorse feelings of personal or group emptiness, the more we are forced to define ourselves in opposition to those around us. Because of our celebration of emptiness, there is no “us” without our difference from “them.” What Corrigan calls weak “positive in-group identity” tends to result in polarizing and even violent opposition between different groups.Footnote ⁹ These oppositional energies have been abetted by the unique diversity of American Christianity: Christian groups proliferated in the wake of disestablishment, creating the crowded train that is American Christianity.

This is a fresh way of understanding American Christian history. It points to powerful theologized feelings to account for stubborn conflicts, divisions, and resentments that have pitted Americans against one another. It is compelling, for example, to think about Baptists' distrust of creeds through the lens of Christian longing for a feeling emptiness. The desire to leave space open for God warned Baptists away from too much trust in words that might limit or crowd God out. But keeping those creedal spaces empty has not stopped Baptists from distancing themselves from one another and from others outside of the Baptist fold. Hollowed out of established doctrine, what passed for doctrinal argument was actually closer to the polarizing rallying of members toward group solidarity against a dangerous world of “others” out there.Footnote ¹⁰ It is not all that different from angry subway riders belittling others on an overfull train—my feeling of emptiness translates into the vilification of others whom I can define as my enemy. The most haunting parts of the book speak of the existential and theological roots of violence against people of color; Euro-Americans' own longings for a holy emptiness were projected onto Amerindian and African people, whose suffering at the hands of white civilization was portrayed as an emptying of demonic religious, ethnic, and racial inheritances. Emptiness makes enemies.

The feeling of emptiness, filtered through and encouraged by a Christian lens, is convincingly portrayed in this book as a spur of social differentiation, of polarization, and even of violence. Corrigan argues that the social impact of kenosis is largely a matter of division and discord. This perspective resonates with the portrait of protestantism presented in the 1896 novel, The Damnation of Theron Ware.Footnote ¹¹ In this proto-realist tale of American disillusionment, the title character struggles to make sense of the austerity and community border-patrolling of the Methodist community he is assigned to lead. Ware is flummoxed as his congregation competes with the prominent Baptists across town through elaborate display of their unworldly emptiness. Readers feel the pain of this competition when Alice, the innocent wife of the Methodist minister, is asked by two severe trustees of the church to remove the flowers from her hat. When her feckless husband can find no way to resist this race toward ever-more-ostentatious self-emptying, readers mark a distinct contrast with the ministers' other love interest, a libertine Catholic woman whose hats—it is noted—are fully bedecked with flowers.

Frederic's portrayal of Catholicism, while tinged by romantic anti-modernism, nonetheless opens the possibility for questioning Corrigan's application of emptiness as a cross-denominational American Christian motif. Frederic's enlightened (if aloof) Roman Catholic priest, Fr. Forbes, offers a comparison of Catholic and protestant communities for the benefit of the naïve Ware. Catholicism, he explains, is a “restful house where things are taken for granted.” It is a site of communal and sacramental embrace in contrast to the relentless introspection, austerity, and border-patrolling of the Methodist community.Footnote ¹² Frederic seems to endorse this contrast with the example of the flower-filled hat, an image he complements with descriptions of the aesthetic richness of Catholic worship. Later, he portrays a boisterous Catholic picnic filled with celebratory beer drinking, raucous play, and the risqué sight of girls on swings. Frederic saw the divisive qualities of kenosis among protestants, but not among Catholics, whose communal and worship life he portrayed as full, self-possessed, and laudatory.

It may be that the distinctive quality of pluralism that came with disestablishment meant less to Catholics than to protestants: the post-disestablishment sense of competition did not really change for Catholics—there was really only one undifferentiated religious “other” (protestants) against whom Catholics had to “push off.” With a lesser diversity of foes against whom they had to identify themselves, Catholics may have had a greater chance to develop “positive in group identity.” As Corrigan notes, the proliferation of rituals such as processions through the mid-twentieth century was certainly more a filling of space than an emptying. Likewise, the dominance of what Corrigan calls “Calvin's Legacy”Footnote ¹³ would have been less marked among Catholics. One does not find among Catholics the tortured ritual journeys between the poles of over-confident “security” and utter despondency evident among Thomas Shepard's puritan congregation. While Catholics were reminded of their fundamental need for the sacraments, there was among them no parallel sentiment to that expressed in John Cotton's catechism reminding readers of their “corrupt natures” “bent unto sin and only unto sin.”Footnote ¹⁴ The Baltimore Catechism, by contrast, spoke of inheriting from Adam a “strong inclination to sin.” The seven “capital sins” (feelings of pride, covetousness, lust, anger, gluttony, envy, and sloth) were special trouble specifically because they were the “sources of actual sin.” Between “inclination to sin” and “actual sin” it was possible to place realization of God's presence through prayer, the sacraments, recognition of the Holy Ghost within, and our own ability to resist temptation.Footnote ¹⁵ Life was still a battle, but human nature offered reserves that made its total emptying perhaps less desirous.

Even the flow of blood so famous to Catholic aesthetics is more about the presence of the blood than about the “emptying of blood” from the body.Footnote ¹⁶ Christ's body and blood fill the Catholic crucifix. Protestants, Catholics aver, proved in their stripping of the altars that they do not trust the blood (just as Baptists do not trust creedal words); they seem to suspect that it too might be empty—a path toward worldliness. On these grounds, Catholics aggressively asserted their substance and thus superiority over protestants. For their part, even as they found their own ways to surround themselves with Christ's blood (eighteenth-century Moravian worship, for example, or twentieth-century evangelical t-shirts about “His Stripes”) American protestants often performed their empty identity by accusing others of fullness in the form idolatry. The feeling of emptiness may have more intensity and more traction in protestant than in Catholic circles.

A related question has to do with Corrigan's thesis about the connection between emptiness and social differentiation. Again the history of Catholicism suggests an alternative. Consider the example of the radical Catholic left, in particular the journalist and activist leader of the Catholic Worker, the convert Dorothy Day. Corrigan's book mentions Day briefly. He sees Day's childhood memories—she talks of being haunted by a terrifying sense of a universal void—as an example of the persistence and continuity of emptiness as a central motif in American Christianity. Day's autobiography, entitled The Long Loneliness, portrays her conversion as a journey from an “empty” secular world into a world of sacramental and ritual density manifest in the communalism of urban immigrant Catholic subcultures. Day depicts her conversion as a matter of feelings rather than doctrines: she says she was willing to become Catholic simply because the poor—through whom she sought to fill the chasms of her emptiness—were themselves Catholic. She writes that she converted without even knowing what the church taught.Footnote ¹⁷ We have good evidence here in support of Corrigan's argument that feelings, and particularly feelings of emptiness, are often more vivid and more important than doctrines. We would do well to join Corrigan in the search for feelings that might have been overlooked in our reconstructions of the religious past.

Any fulfillment that Day found in solidarity with the poor, however, later gave way to a much more radical desire to empty the self: as James T. Fisher and Jack Lee Downey have shown us, her conversion into Roman Catholicism was only the first of two conversions, the second drew from an intense Jansenist retreat spirituality calling not just for voluntary poverty, but for comprehensive self-mortification.Footnote ¹⁸ One must join in Christ's suffering (which meant an emptying of the ego and the abandonment of the pursuit of material or mental comforts). As Fisher writes, for Day and her allies it was Christ's self sacrifice, even more than his moral heroism, that Christians were called upon to emulate.

It is true, in keeping with Corrigan's thesis about emptiness and social differentiation, that this intense spirituality of self-mortification contributed to a split in the Catholic Worker movement: for a time Day insisted that those in the movement must participate in retreats led by her favored spiritual guides. Many deemed it too severe and branched off. Day also took this spirituality of self-mortification and used it to differentiate herself from the upwardly mobile and increasingly “bourgeois” suburbanizing mid-century Catholics of her day.

But alongside these ironies and divisiveness, Day's pursuit of self-emptying was a driver not just of social differentiation, but also of a more radical sense of social unification. Day tells the story living through the San Francisco earthquake of 1906. Retelling the story several decades later, she drew a lesson from the sense of community solidarity that prevailed after the shaking stopped. Her autobiography includes the story of tattered families streaming into Oakland from San Francisco, and of the erasure in that moment of all sense of personal property. Every stitch of clothing and piece of food was no longer owned, she remembered, but available to anyone in need. This memory became a philosophy for Day: we live, she averred while looking at a world rife with economic disparity, racial oppression, and violence, in a perpetual state of post-disaster; anything but self-emptying care for others is not only less-than-ideal, it is downright unseemly, like denying your own family members a place to sleep. In Day's hands, kenosis was not an opportunity to articulate a scheme of salvation differentiating Christians from non-Christians, or Catholics from non-Catholics, or bishops from priests and laity, but instead a way to affirm all of humankind as cosmically and genuinely unified precisely in their vulnerability and their human dignity. The realization of emptiness was a precursor to universal communion.

If I can stretch my guiding metaphor a bit longer, I have seen something similar happen on the subway: when a train gets stranded in between stations, there is at first a heightening of tension as groans and curses rise up across the car. But after a certain amount of time, the agonistic atmosphere softens. A shared sense of utter helplessness takes over; you get the sense that people realize they may be stuck alongside these others for a while, and—shockingly—these others transform from obstacles in one's way into people equally vulnerable, equally beleaguered, equally deserving of relief. If the delay lasts long enough, people start to share eye rolls, mild banter, and even laughs. The recognition of mutual emptiness (over and against the mysterious powers of the MTA) spurs recognition of mutual dignity.

There is no reason to think these revelations inspire permanent transformation. The struggles of Day and the Catholic Worker Movement witness to the difficulty of sustaining such insights. But their attempts to cultivate a sense of humankinds' shared vulnerability produced one of the most significant religious movements of the twentieth century. They built on those feelings to produce a nationwide network of social care and a tradition of journalistic critique and pacifist protest against various structures of violence. Admittedly, there is friction or “pushing off” here, as American individualism and American exceptionalism—or, as Corrigan might have us see it, American “fullness” of self—become threats to be overcome. As Fisher shows, Day and her co-founder Peter Maurin set terms for the movement by which failure in the eyes of “the world” was—at a deeper spiritual level—actually triumph. But their call for emptying was, ideally at least, also the root of an unwillingness to use force, an unwillingness to place oneself above others, and a willingness to suffer serious personal losses not merely for the sake of suffering or the performance of difference but as a witness to a deeper union of all of humankind in and with God. Here, at least as it was meant to work, emptiness refused enemies. One need not turn a blind eye to the frictions and ironies of the history of the Catholic Worker in order to wonder whether the feeling of emptiness, not just theologically-speaking but in terms of actual social results, has not also served to bind one to another.

These are provisional questions about a work I deeply admire. Corrigan has done us all a great service; transcending narrow accounts of small subsets of American Christians, he has offered a bold and invigorating argument covering a vast sweep of American history. It is not only a provocative new way to think about American religious and social life, but it also serves as an invitation to consider feelings and their complex varieties, dialectics, and flows as specific historical realities, mediated and shaped by religion as much as they mediate and shape religions themselves. I am confident that this work will produce a new wave of scholarship by intrepid historians taking up distinct sets of feelings and trying to track their sources and their contributions to American religious, social, and moral imagination. I doubt many will be as elegant, supple, and thought-provoking as Corrigan's work. I am grateful to have had the chance to think with this piece; neither my research nor my commute will ever be the same.