In Catholicism and American Freedom (2003), historian John T. McGreevy described the Catholic Worker as “the most important radical Catholic movement in American history.” At seventy-five, the Catholic Worker is certainly the most long-lived and written-about venture of its kind in American Catholicism. And while this lay movement’s charismatic founders, Peter Maurin (d. 1949) and Dorothy Day (d. 1980), are long departed, the Catholic Worker movement continues to grow in vibrancy and versatility.

That is the thesis of The Catholic Worker after Dorothy, Dan McKanan’s follow-up book to Touching the World (Liturgical Press, 2007), his study of intentional Christian communities that attempt to transform society. McKanan uses interviews with Catholic Workers from across the country; primary and secondary sources on the movement; and his own sociological analysis of how small faith communities define themselves, attract members, and prosper or decline.

Chair of the theology department at the College of St. Benedict and St. John’s University in Collegeville, Minnesota, but not a Catholic himself, McKanan was introduced to the Catholic Worker as a student by Robert Coles. McKanan acknowledges his new book is not an exhaustive study of the Catholic Worker. Instead, it offers a general account of the movement since Day’s death, and presents a plausible set of explanations for its continuing longevity and growth.

McKanan traces four successive generations of Catholic Workers, describing how each approached what he calls the Catholic Worker’s “hermeneutic of hospitality.” The heart, and the art, of the Catholic Worker is how it “welcomes the stranger” in a thousand guises, and how it does so in response to local conditions. Both the variety of approaches found in the different houses and the movement’s organizational decentralization are key to its post–Dorothy Day success, McKanan writes. He supports his case by describing the distinctive approaches of a number of Worker communities across the continent. Unfortunately, some of the communities are treated so briefly they tend to meld in the reader’s mind, and what is distinctive blurs. The New York City houses barely merit mention in this section, a curious lacuna, given that they would have been the most likely to be affected by loss of the founders.

The second half of the book presents a more thematic analysis, and here the New York Worker plays a more prominent role. This section deals with questions about the movement’s “aims and purposes”; what has been the role of the nuclear family in Catholic Worker houses and on its farms; how various Catholic Worker communities relate to the Roman Catholic (read, patriarchal, sexist, and reactionary) Church; and finally, what is the long-term outlook for this unincorporated communitarian movement, given its history and philosophy.

While not claiming the numbers approach megachurch growth, McKanan reports that there are today twice as many Catholic Worker houses as there were in 1980. According to a self-reported survey, there are more than 180 houses in roughly 150 cities, not including a dozen associated farms. In describing this “kaleidoscopic web” of loosely associated communities, McKanan argues that the wisdom of the Catholic Worker model has been its ability to function as an organism rather than an organization. He attributes this to Dorothy Day who did not anoint a successor and who accepted a variety of communities that did not slavishly follow her New York paradigm.

What has historically drawn volunteers of all ages and beliefs to the Catholic Worker has been its daily practice of the works of mercy—feeding the hungry, housing the homeless, clothing the naked, visiting the sick and the imprisoned, instructing the ignorant—and its attempt to live a Christ-like life of poverty. The movement has done this in the form of nonviolent communities of resistance that hope to build what Peter Maurin called “a new society within the shell of the old.” This demanding vision is precisely what gives most Catholic Workers a sense they have achieved very little in all these years. Yet on a good day—and most days are good—Catholic Workers themselves will attest that the life they have chosen is more liberating and exhilarating than any they could have imagined. Indeed, most of the impressive individuals McKanan writes about in this book are eminently sane and likable, albeit uncommonly dedicated and possessed of a strong anti-establishmentarian streak.

What’s missing in McKanan’s study is a sustained analysis, both historical and theological, of the Catholic in the Catholic Worker vision. I don’t mean the fussy, even reactionary gambit proposed by some individuals McKanan interviews—who apparently think of themselves as the only “orthodox Catholic” Catholic Workers left. Nor those whose views have been strongly influenced by Protestant scholars like John Howard Yoder or Stanley Hauerwas. (The Catholic Worker has always relied on a wide scope of Christian thinkers and visionaries—including Martin Luther King, William Stringfellow, and Jacques Ellul.) I’m thinking, rather, of the individuals and communities that identify themselves as being “in the Catholic Worker tradition” instead of simply “Catholic Workers.” The author doesn’t seem to question the impact a weakened association with Catholicism might have for the future of the movement. He takes for granted certain “progressive” notions about gender roles (such as women’s ordination) and sexual orientation in the current movement, and presents them as essential elements of Catholic Worker ideology. But his uncritical approach fails to examine the principles that underlie this radical Catholic movement, a movement that historically avoided sectarianism by consistently weighing its aims and purposes in light of the Gospels and Catholic tradition.

Like any number of studies dealing with the Catholic Worker, at points this one paints with too broad a brush. At others, it makes minor claims at the expense of historical accuracy. For example, the circulation of the Catholic Worker paper was 35,000 in 1934, not 100,000—a remarkable figure that was reached the following year. (The Catholic Worker’s most recent press run was 45,000, down from over 80,000 in recent years. Rising production costs and skyrocketing postage forced the editors to do a serious culling of the mailing list.) Dorothy Day’s arrest with the United Farm Workers in 1973 was not her “last major public act.” That was her address at the International Eucharistic Congress in Philadelphia in 1976. Peter Maurin was not an ex-seminarian; he had been a Christian Brother in France. And concerning the late Gordon Zahn’s 1988 Commonweal article criticizing a Catholic Worker house for “celebrating” a Eucharist without an ordained priest, McKanan comments that “perhaps the most interesting feature of this debate” (Zahn’s article was one of three discussing the issue of priestless Masses, pro and con) was “that it did not provoke a single letter of response from any active Catholic Worker.” In fact, the articles led to four pages of published correspondence in Commonweal, the longest letter written by Eileen Egan, an esteemed longtime associate editor of the Catholic Worker.

Despite such lapses, McKanan’s book focuses needed attention on the growth, creativity, diversity, and indeed longevity of the nation’s most important Catholic radical movement. It also demonstrates that the seedlings Peter Maurin and Dorothy Day planted seventy-five years ago have taken root, borne fruit, and sent off new tendrils of their own. The next twenty-five years ought to be interesting ones—both to be part of and to report on.

Related: A Faithful Striving, by Robert Ellsberg