OF STONES & STORIES.

The Geometry of Love
Space, Time, Mystery, and Meaning in an Ordinary Church
Margaret Visser
North Point Press, $27, 262 pp.

Every reader of Margaret Visser's new book--and may there be many--will be able to pinpoint the precise moment when he or she gets hooked. For me, the moment came in chapter 2, where a discussion of sacred space in ancient Rome became an extended meditation on the Hebrew exodus from Egypt and Solomon's construction of the great temple at Jerusalem. For another reader it may be the reflection on the symbolism of the number eight, or the comparison of a visitor's descent into a church with Aeneas's descent into the underworld in book VI of the Aeneid. In The Geometry of Love, it's one tangent after another.

As the subtitle indicates, Visser's inspiration arose out of her frustration at the lack of information that was truly revelatory, as opposed to merely factual, in the many churches she has visited. Seeking more meaning, she chose an "ordinary" church, Sant'Agnese fuori le Mura (Saint Agnes Outside the Walls) in Rome, and learned everything she could about it. Readers familiar with Visser's acclaimed Much Depends on Dinner, a brilliant essay on the social meaning of eating, will recognize the technique.

A classicist by training, and a relentless researcher, Visser draws on a breathtaking array of disciplines--architecture, history, folklore, theology, anthropology, and etymology, among others--as she takes the measure of Saint Agnes's. The book's subtitle seems slightly disingenuous: a thirteen-hundred-year-old church built over the tomb of a young virgin martyr in Rome, brimming with statues, mosaics, and portraits, may strike most readers as anything but ordinary. (How well, one wonders, would her method apply to a truly ordinary church, say, a sparsely decorated post-Vatican II circular church in a midwestern suburb?) Still, as its title suggests, the book's organizing principle is the church's architectural space. Each chapter corresponds to a different part of the building: crossing the threshold into the narthex, we make our way through the constituent elements of the structure, concluding our tour at the tomb of the virgin martyr for whom the church is named. To read the book is to experience the church, visually and physically, as a visitor would.

One of Visser's most likable qualities is her willingness to follow her curiosity wherever it leads. She is an erudite and chatty tour guide venturing off on a new angle of discovery every few paces. Take chapter 5, for example, on the apse (although any chapter would do). Visser begins with the tangible--the mosaic of Saint Agnes flanked by two papal companions--goes on to the obvious topic of the history and technique of mosaics, but also includes Christianity's appropriation of the myth of the phoenix, the history of haloes in religious art (these days, she comments, "We are far more interested in feet of clay than in aureoled heads"), and Therese of Lisieux's girlhood visit to Saint Agnes's, during which she pocketed a fallen mosaic stone. There's more: a concise and informed summary of the Monophysite controversy that divided East and West in the seventh century, a brief history of palliums, an account of Pope Honorius's building projects, and a final reflection on the light and life conferred on the world by Christ's sacrifice on the cross. Even the footnotes are gems: number 15 points out that palms were not native to Jerusalem but imported for the Feast of Tabernacles.

None of this is random, of course; The Geometry of Love is nothing if not beautifully constructed. Rather, each new topic arises effortlessly out of its predecessor. It makes perfect sense, for example, that a discussion of the placement of the baptismal font should lead to reflection on the need for Christian forgiveness. In her breathtaking display of scholarly prowess, Visser never loses her pilgrim's footing. Indeed, some of the best writing interweaves architecture and object with matters of the spirit. Not surprisingly, the author of Much Depends on Dinner is quite good on the Eucharist: "It is as food and drink--the object for human beings of endlessly renewed desire, necessary, simple, ordinary, to be broken and shared, of external matter that becomes internal, and which then turns into the very substance of the eater--that the Christian God of love sacramentally gives himself to human beings." Here is not only knowledge, but something rarer--true understanding.

Visser rejoices in the smallest of details--the fact that two popes died of colds they caught at Saint Agnes's, or an eighteenth-century Anglican clergyman's conviction that the alabaster statue of Saint Agnes behind the altar was in fact a statue of the Greek god of revelry, Dionysus. She has a gift for enlivening ordinary things with meaning, such as her vision of a row of columns "striding through space." An inveterate etymologist, she discloses the origins of words in an always illuminating way. Who knew, for example, that the term "curfew" originated in the French couvre-feu, or the "covering of the fire" mandated by the final ringing of the town bells at night in the Middle Ages? Or that "narthex" takes its name from the Greek word for "fennel stalk," commonly used as a container in the ancient Mediterranean world?

As Visser approaches the tomb of Agnes, neatly construed as the book's conclusion and the church's beginning, she observes, "A church labyrinth...is not like the Cretan one: what potentially awaits us here is not a monster, but an epiphany." Above all, this is a book of epiphanies, of meanings revealed. It is a repository of information and fact, just as the tomb of Agnes is a repository of the saint's bones. But like the saint's grave, which is both a gateway to eternal life and historically the seed of Saint Agnes's itself, The Geometry of Love confers new life on everyday things, transforming our experience not only of this particular church but of all churches.

Elizabeth Kirkland Cahill, co-author with Joseph Papp of Shakespeare Alive!, is a frequent contributor.