"There is indeed something magical about enchanted ground," Barbara Newman observes at the end of this landmark report of her expedition through the looking glass of chivalric literature.  Looking backward on her explorations, she says that she had marked "many paths untaken," and had left unsaid much that she had seen. Others might take up where her "meandering path" ended. They would find, as she (and other discoverers) had done, that the territory did not yield its enchantments easily; for it was, after all, "the pathless waste forest of romance" (262-3). Fans of knightly quests know that that forest is "perilous," and that such journeys are pitted with ordeals. To give the gist of her expedition report, I shall begin by saying how she framed her campaign differently from other adventurers into the same mysterious terrain. Then, I shall sketch out some results of her observations.
Newman frames her book with near and distant focal ranges. As to the near range, she places her book in the specific context of a by-now classic scholarly debate between two literary critics, D. W. Robertson, Jr., who characterized medieval literary theory as spillover of Biblical exegesis into the theory and practice of vernacular writing, and E. Talbot Donaldson, who stressed the birthing of secularism in departures from the medieval notably by Chaucer (1-7). For Newman, as for Robertson and Donaldson and their followers, the materials under discussion were vernacular literature (ca. 1100-ca. 1475) on both sides of the Channel, Anglo-Norman, Middle English, and French. What did the distinction between sacred and secular mean when, as all disputants agreed, vernacular and latinate cultures interpenetrated one another? The first stages of the Donaldson-Robertson debate faded away, leaving this central mystery and much else unsolved, so to say, a cold case.
Periodically, taking account of new evidence, and revised methods, and the burgeoning field of vernacular theology, scholars called for a review of the cold Robertson-Donaldson case. Newman's book comes as a particularly incisive response to a persistent chorus of such encore calls.  Though there was no question of making an entirely new beginning, she did consider that a new orientation and correspondingly altered objectives were called for. The magnetic pole to which she sets her compass is exactly the dyad of sacred and secular between the twelfth and the fifteenth centuries. Her objective is to "reconceptualize...the relationship of sacred and secular in medieval literature" (1). She gives the key to her strategy in her title, with that one oracular word, "crossover." Some swivel-connection is meant. Of the many possibilities, which paradigm or frame of reference does she have in mind?
As a practiced trail-blazer, Newman has left coordinates of her trek back and forth through the ages at strategic points (ix-xii, 167, 223, 257-262). Let us hold to that dyad of "sacred" and "secular," which latter, we learn, is identical with "profane" and includes both "pagan" and Christian laity. It would be good to remember that crossovers between sacred and profane as two wings of the same social whole are due to the Apostle Paul's doctrine that all Christians are members of one body, the body of Christ. An incalculably great leap forward came in the Late Roman Empire, with the doctrine that Christ ruled his body through two human agents, the sacred authority of bishops and the power of the emperor. This dualism disintegrated and perished in social multiplicity from the Renaissance on, Newman's "early modern shift," at length canonized in the separation of Church and State. After that, what had been a duality of sacred and profane became parallelism.
Newman pays homage to all sides in this debate when she proposes, in her project of reconceptualization, to set forth "an overarching comparative framework to discuss the interplay of sacred and profane in (primarily) French and English texts." Yet, she quickly withdraws from any hint of proposing absolutes by laying "no claim to a totalizing paradigm" (17). In fact, her readings lead her to visualize fluidity rather than linearity. Though she does not use the term "synergy," the "symmetrical model" she proposes is a synergism of interactions, and a variable one. According to that model of swivel connections, secular and sacred flowed together, capable now of remaining "distinct" like oil poured together with water, or, again, blending, made potentially intoxicating, like water mixed with wine (7). According to her reading of chivalric romance and vernacular theology, love was the point of interaction, both in secular texts, as fin' amor, and in sacred, as the Love that is God considered in the divinity itself or, by likeness or in-dwelling, God-in-humanity.
Apart from immediate and remote backgrounds, Newman also uses visual images to frame the model or paradigm of her subject. She envisions the "fluid play" of courtly and spiritual in a more complex way, as streams springing from "the Fountain of Love that waters so many lush planted gardens, with diverse streams from that fountain crossing, intermingling, and leaping back on themselves" (111). Perhaps her most complex and nuanced analogies are to music. Considering literature of different genres, schools, and cultures, she thinks of their intersections and crossings as being like polyphonic music. For, in the era with which she is concerned, polyphony began as a revolutionary innovation and developed to an astonishing height of interlacing words, voices, and melodic lines, letting individual listeners follow whichever caught their taste or "perspective" as signifying the whole (12). In polyphonic music, setting sacred words to secular music, and vice versa, was only the most elementary level of crossing-over (122, 126, 167, 169-170). In view of the intricacy of stories about love, death, and treachery, the substance of romance, Newman is right to give the double-cross a place in her repertoire of swivel connections.
All the same, in hydraulics or harmonics, assimilations, improvisations, and indigenations were exercises in hybrids of "dissimilar likenesses." In their synergising interactions, including rhetorical double crosses, they could depart from the original, deform, or even--as some sections of Newman's book demonstrate--parody, mock, and subvert it. Occasionally, Newman imagines crossing-over between the two registers of sacred and secular as mediated by a third term, or catalyst, rather as the classical syllogism moves toward resolution of major and minor premises through a "middle" premise. Newman takes the vocabulary for this pattern of transition from a master of chivalric romance, Chrétien de Troyes, when she speaks of pagan matiere (material) and Christian sen (understanding) resolved in secular conjointure (combination) (23, 25, 26, 56, 260).
In a searching discussion of the writer now ordinarily referred to as Marguerite Porete, Newman characterizes the mystical blend of devotional theology and trouvère expression in a variant of such a three-part swivel (157-158). 
Theodicy is the threshold by which Newman begins to ground the ethos of "crossover" in the heart of Christian doctrine (13-25), and, by extension, into the transgressions of chivalric romance. With its paradoxes and enigmas, theology showed how to formulate and affirm contradictions in the natures of entirely secular events and things, as well as in Scripture. Rhetoric provided many devices for crossovers in secular poetry as well as in hymns, breaking through boundaries of words to form pictures in the mind: for example, allegory, denoting one thing by referring to another; irony, for saying one thing while your words express the opposite; and parody or travesty, masking realities by caricaturing them. Newman illustrates moments when these forms of double crossing over, especially allegory and parody, developed in controversies over sacred doctrine and there, spliced together with paradox, were used to reflect on and to form, break, or recast moral ambiguities and ambivalences in secular history and fiction.
With conversion, Newman expands the range of crossover by double-speak, double coding, and double judgment from sacred quandaries, represented by felix culpa, to the imagined communities of chivalry. In literature, she illustrates the use of theodiceal double vision concocted in the alembic of secular mentalités most breathtakingly with an episode from chivalric romance, blending Christian Scripture and ritual with pagan practices of beheading and cannibalism cross-culturally read as baptism (77-8). Through actual conversions, secular and sacred, cultures blended in the lives of writers and their patrons and audiences. Individual human beings engaged living crossovers between sacred and secular as swivel connectors in their memories, and so in their thinking and ways of life, as they moved back and forth across class and social borders. It is no surprise that they applied their handiness with negotiating assimilations when poems or books or music written for chivalric orders were cannibalized for use in devotional works.
Hermits also enter Newman's story, in a way similar to that made familiar by Peter Brown in his studies of the liminality of holy men in Late Antiquity. The ideal of contemplative flight from the world "into the solitude of the desert" was early hybridized with the militant ethos of monks (milites Christi) overcoming the world, beset at every step along their pilgrimage by demonic temptations and grappling in life-or-death combat with spiritual enemies before the eyes of God. Analogies were ready to hand here for ordeals of the knightly quests, beset by deadly enemies, in a dense and threatening forest waste. Not only were hermits "liminal" in mediating between sacred and sacred, but their own lives were often instances of conversion into crossover: "retired knights, often kin to the [knightly] heroes they advise and assist" (79, 82-83). For between knights and hermits, "the asceticism of the forest hut was perhaps not so far from the ascesis of the battlefield" (82). To these living crossovers, Newman adds a remarkable ensemble of others recorded, not only in romances, but also in purported accounts of actual virgin martyrs, transvestites, and holy sinners (37-530).
Newman adduces romances and hagiographies as evidence of the cultural preconceptions about ambiguities of identity that sustained the double-sided crossover between sacred and secular in actual as well as in imagined experience with which she is most concerned: the self-assimilation of the "chivalric class to a less austere standard of holiness, even as it subjects holiness itself to the prowess and pedigrees of knights" (83).
Thus, Newman's re-framing of the Robertson/Davidson debate has revived that cold case; but, as often happens in reviews of cold cases, the review has posed the unsolved mystery in a different way. A notable result of Newman's analysis is that from theodicy it leads resolutely, not to closure, but to open-endedness. It leads, not to the closure desired by established teachers and rulers of the Church, but to an existential void anticipating those of Pascal and Kierkegaard. It is present in the author of the celebrated treatise attributed to Marguerite Porete, The Mirror of Simple, Annihilated Souls, Who Survive Only in the Will and Desire of Love.
The author of The Mirror considered what she wrote to be God's own gift reflecting the divine image. And yet, her book was not the image it reflected, anymore than a portrait is its living subject. "Yet the divine mirror, is in the end a mere painted image... 'made by human knowledge and human sense,' and 'all that one can say or write of God...is to lie far more than it is to tell the truth'" (157-8, quoting The Mirror). Witnessing to the difference between the image of the Beloved and the actual Beloved, the author also witnesses to a sadness like that of frustrated, unconsummated love in chivalric romance. Yet, the author went beyond the capacity of the book as cross-over. For the frustration of apprehending the Love of God through the medium of the book was relieved when, becoming one with God, the author herself crossed over and was annihilated in the divine, free of all except for the will and desire to be subsumed in the abyss of divine Love.
One condition for stability in social values is a general agreement to accept what are known to be fictions, or fantasies, as though they were facts: that is, a consensus on how to "straddle the boundaries between sacred and secular, truth and fiction--or the history that was and the history that might have been" (72). The "early modern shift" came at a moment when seismic upheaval was breaking the tectonic plates of that consensus apart. As for the long era before the fifteenth century, much of Newman's study turns on dramatic wavering between severity and doubt in the enforcement of social controls. She is surveying fault lines that broke open in the systemic failure of the eighteenth century.
Narratives of chivalric adulteries (Mark, Tristan, and Isolde; Arthur, Guenevere, and Lancelot) owed their psychological and dramatic intricacy to their "double coding," the one side favorable to the offended, the other, to the offenders. Uncertainties multiplied as authors multiplied perspectives and left multiplex endings of their narratives, open to "the hermeneutic strategy of double judgment," or even more widely, to the individual reader's perspective (35, 56-67, 69, 86, 94, 169, 221, 258). Many-stranded in their double coding, the plot was lost without closure by the end. Great moral ambiguities in Greek tragedy had their closure in Fate. Although they make only one dramatic, if cameo, appearance in Newman's chapters, extreme ecclesiastical methods of societal enforcement, capped by excommunication synchronized with the secular penalty of burning at the stake, were in the minds of authors and readers of these texts. After the late twelfth century, so was the extra-legal, but still often organized, strategy of several days' popular uprising, the pogrom, massacre and plunder against the Jews, represented in Medieval Crossover by The Passion of the Jews of Prague according to John the Peasant (1389). Newman leaves it to readers to decide for themselves whether, as she suggests, there could be double coding, a shadow of doubt in the "textual unconscious" of the boastful writer of this bloodthirsty parody of Scripture. 
In re-opening the cold case of the Davidson/Robertson debate, Newman could only reach allusively to implications of the material that shot into the higher reaches of Dante's celestial journey. However, the development of a conflicted mentalité at odds with authoritarian ideology seems to me one of the most difficult and rewarding avenues that her study has opened for future exploration.
From time to time, the ancient myth of Narcissus enters Newman's account, as it entered into the literature she discusses. In the beauty of his youth, Narcissus caught sight of his own face in a pool and, infatuated with the sight, died of starvation, feeding on the empty image of himself in the water, that "perilous mirror." The effects of knightly and hagiographical romance--and, for that matter, of Scripture--lay in the willing, even ardent, desire of audiences to see themselves in the texts and to re-tailor their lives, reproducing patterns they found in the mirrors of words. But Marguerite Porete was not the first or the last to know the fatal difference between the image of God and the image she created in her book. Construing Newman's achievement invites thought about this connection between texts turned into perilous mirrors of fiction and the virtual procreation of life through art.
That connection is present in one crossover, far more widely-arching and permanent than that between sacred and secular, everywhere implied and nowhere worked out. From all its sources, the synergy of sacred and profane drew energy from the crossover "from fantasy to the real and back again." Yet, in case study after case study, Newman has come to the crossroad where these paths intersect in trauma. The venture of matching desire to reality is full of perilous journeys through wastelands of disappointment, risk, and mirages. Was the suffering inevitable because art, myth, and formal institutions had already infiltrated reality with illusions: "with symbols and codes so that the real [was] full of the imaginary anyway"? 
It goes beyond Newman’s treatment, but remains within the trajectory of her material, to remember that--both for individuals and for whole populations being transformed from generation to generation as they moved toward the consummation of the ages--the drama of these intersecting narratives of trauma turned on mutation. By radical changes of identities, people were being transformed from what they were into something they had not been. They were being shaped by blows between the hammer and the anvil. Can pain, individual and collective, have been inscribed in the continuing process of indigenizing the ethos of Christianity, the product of earlier centuries and cultures, to the reality of Romanesque and Gothic Europe, itself in so many ways, “a pagan world, still in the throes of conversion” (26)? As to the indigenation of an uneasy amalgam of Christian and pagan myths, one thrust of chivalric romance, could the three-part formula that Newman derived from Chrétien de Troyes contain a recipe for collective trauma, or rather for chronic assorted traumas in various areas of society? The formula called for a liberal anointing of pagan material (materie) with Christian meaning (sen), to produce a chivalric (=secular) mingling (conjointure). The critical act of imbuing non-Christian or anti-Christian materials with Christian meaning (senefiance), Newman realized, lacked the great restriction on Christian interpreters of Scripture: that they should be true to the intention of the divine Author.
To the contrary, indigenators between fantasy and reality were free to follow their own perspectives. They could bestraddle Pegasus, the magic steed of Greek mythology, emblem of the Muses and cavalry, and soar above "the boundaries between truth and fiction" (72, 259-261). Indigenators need not ride Pegasus toward the same destination. Poets and their audiences varied in perspectives. There was something divisive in the fact that the decisive thing was to impose on ill-matched oddments a mythic line, a "senefiance that would [make]...sense to the poet's audience" (64). Thus, chivalric poet-mythographers played with the pagan remnants, paradoxically hybridized with the sacred and the secular, constructing "the sacred itself" in such a way as to raise knights (chevalerie), not clergy (clergie), "to the highest and holiest rank," a "sacrality" that preserved virtues distinguishing warriors from women and priests (82, 260).
Perhaps Pegasus knew discrepancies between his poet-riders' fantasies and their realities better than they did, confused as he must have been by their contrasting styles of equestrianism. By following Newman's track, we have some sense of how crossovers enabled hybridizations and assimilations of alien traditions, pagan, sacred, and knightly. We also have found that crossovers led people of different perspectives to quite irreconcilable consequences. Perhaps, if we look more closely at what Newman considers that her expedition has accomplished, we shall be able to take the measures of crossovers as social artifacts, both products and tools of mutation, cohesive for some, divisive for others.
The undeclared subject of this book is nothing less amazing or mysterious than the procreation of life through art. From the altitude of a medium-earth-orbit satellite, Newman's "meandering path" and its side-tracks describe an intricate pattern, crisscrossing and double-crossing, as elaborate as the swivelings of Love. Like an electrocardiogram, these are tracings of stress points in a population's conversion into another stage of life. Did not Dante think of such a thing when he wrote of humanity's mutation, no doubt with growth-pains, from a larva into a butterfly (Purgatory, I.10)? Thanks to Newman's game-changing encore to the Donaldson/Robertson debate, we now can see a way to speak of crossovers between secular and sacred as tools of indigenation, and of indigenation as a protean driver in the evolution of social values.
 Medieval Crossovers first appeared as a lecture series at the University of Notre Dame in 2011.
 Alan T. Gaylord, "Reflections on D. W. Robertson, Jr. and 'Exegetical Criticism," The Chaucer Review 40 (2006): 311-333, p. 312.
 It is a measure of the eminence Marguerite Porete and her ideas have fairly recently assumed in the history of spirituality that so much about her is obscure. Even the essentials remain open to debate. The Mirror of Simple Annihilated Souls (a.k.a., The Mirror of Simple Souls) has widely been attributed to Marguerite, as is done by Newman. However, while Medieval Crossovers was in press, the doyenne of French medievalists, Elizabeth A. R. Brown, wrote and began publication of a series of studies challenging the evidence for that attribution with massive documentaion and exacting methods. As Bernard McGinn wrote in his magisterial account of The Mirror of Simple Annihilated Souls: "like her book, Marguerite presents us with many mysteries," including, now again, secure authorship of The Mirror. Bernard McGinn, The Flowering of Mysticism: Men and Women in the New Mysticism (1200-1350) (New York: Crossroad Publishing Company, 1998), 244; Elizabeth A. R. Brown, "Marguerite Porete, John Baconthorpe, and the Chroniclers of Saint-Denis," Medieval Studies 75 (2013): 307-344, with further works cited p. 307, n. 2.
4. Newman, Medieval Crossovers, 185, 201, 259: "By reading The Passion of the Jews of Prague against the grain, I turn the tables, for once undermining the literal sense of that problematic text in the Jews' favor." See Susan L. Einbinder, Beautiful Death: Jewish Poetry and Martyrdom in Medieval France (Princeton, NJ: Princeton University Press, 2002), 8, 29, 47-48.
5. Cecil Balmond, Crossover (New York: Prestel, 2013), n.p.