The book, "intended as a provocation, and not as a definitive statement" (119) is, from the point of view of a medievalist, provocative in ways wholly unintended by the author. Boyarin's main thesis is that the ways in which medieval Europeans imagined and treated Jews and Muslims influenced the later discourse about and treatment of Indians in the New World. At the same time, the identity of Christian Europe was not a given fact, a rigidly fixed entity. Rather, it was constantly reinvented and shaped in a process in which interaction with these non-Christians played a crucial part. All this is surely true, but Boyarin is not the first to suggest such continuity and interaction.
How the cultural background of conquistadores and missionaries shaped their ideas and behaviour in the New World has been explored in many ways. To cite just a few examples, Sabine MacCormack's On the Wings of Time: Rome, the Incas, Spain and Peru (Princeton: Princeton University Press, 2006), not cited by Boyarin, investigates the use and impact of classical heritage in colonial Peru. Her Religion in the Andes, used by Boyarin, also investigates the Catholic baggage of the authors and how this shaped their understandings. Valerie Flint's The Imaginative Landscape of Christopher Columbus (Princeton: Princeton University Press, 1992) also explores continuities between medieval ideas and the discovery of the Americas. James Muldoon, Antonio Stevens-Arroyo and others have been at work discovering the continuities between Iberian Reconquista and New World colonization. Boyarin draws on some of these results, although he does not try to engage with them in a comprehensive manner. (A recent book uniting in reprint some of the relevant articles and providing further bibliography is James Muldoon and Felipe Fernández-Armesto, eds., The Medieval Frontiers of Latin Christendom: Expansion, Contraction, Continuity, Farnham: Ashgate, 2008). Many scholars, including Gavin Langmuir, Anna Abulafia, Miri Rubin and others (many of whose works are cited by Boyarin) have engaged in analyzing the role interaction with Jews had in the formation of European Christian identities.
What would be a new contribution to this growing field is a systematic analysis of continuities and influences between the treatment of Jews and the treatment of Indians. Yet Boyarin does not intend to explore his themes in any depth, reiterating that he wishes to spark thinking and further research rather than to discover exactly how European interaction with Jews shaped the stance towards Indians. He lists similarities as well as differences between Christian ideas about Jews and Christian views of native Americans. In the end, he does not draw a balance, so readers are left to decide for themselves just how significant the similarities are.
His main emphasis is on Spain, as a place where interaction with Jews and Muslims during the Middle Ages was most intense and also the region from where the conquistadores set out for the Americas. It is therefore surprising that he cites almost no books in Spanish. For example, Miguel ángel Ladero Quesada is represented by one article (in English), while his oeuvre in Spanish on the wars with Granada, Jews in late medieval Spain, mudéjars, and 1492--all relevant to this book's subject-matter--is ignored (for a list of Ladero Quesada's books and articles, see http://dialnet.unirioja.es/servlet/autor?codigo=16538). In fact, the bibliography almost exclusively lists works in English. But even in English, the author fails to make use of such important pieces as Peter Linehan's magisterial History and Historians of Medieval Spain (Oxford: Clarendon Press, 1993) or Yosef H. Yerushalmi's Leo Baeck Lecture of 1982, "Assimilation and racial anti-Semitism: The Iberian and the German Models," which would be salient when discussing limpieza de sangre. He does not use primary sources at all, other than through translations and second- or even third-hand quotations, but draws heavily on the work of various medievalists, so that parts of the book are compilations of paraphrases and quotations.
Boyarin also argues against some theses that have long ceased to be dominant. Notably, he suggests that 1492 is "almost always, and even in critical scholarship" seen as a divide between the Middle Ages and modernity and that has led to scholars' inattention to continuities (55). As noted above, this is no longer the case, at least in critical scholarship. He also implies that Christian identity has not been seen as a dynamic evolution, when in fact research on the transformation of Christian identities over time has become a self-evident truth for medievalists, leading even to the introduction of "Christianities" as in Thomas F. X. Noble and Julia M. H. Smith, eds., Early Medieval Christianities c. 600- c.1100 (vol. 3 of The Cambridge History of Christianity, Cambridge: Cambridge University Press, 2008).
At times, Boyarin makes fairly general points which he illustrates with a single, and not always a suitable, example. In this way, he claims "...becoming Christian is a constant process...Traces of that abjected, divided self, often explicitly identified as the figure of the Jew...continued to haunt Christendom...Making a Christian thus entailed separating the neophyte...from Jewishness" (suggesting that the Jew always remained a hidden part of the Christian self). As evidence, he cites Petrus Alfons; but Peter was a convert from Judaism, and therefore his case cannot be taken as emblematic of Christian identity formation in general (20-21). Similarly, Boyarin claims that Muslims who converted to Christianity still troubled the Christian imagination. The sole evidence for this is one possible interpretation of one late-thirteenth century French manuscript illumination, depicting a converted Saracen kneeling in front of the image of the Virgin; it perhaps expressed a fear of idolatry (52). "Categories of race and gender were subject to...slippages between fixity and fluidity": the sole example cited is the alleged Jewish male flux (72).
Although he is clearly right in emphasizing that the need to sustain a Christian identity lead to aggression and violence, he posits European uniqueness in this way without reflecting on other equally aggressive and violent manifestations of other religious and cultural identities, uninfluenced by Christianity (one could cite any number of mass-murders, for example of Armenians, or of Hindus and Muslims at the time of the partitioning of India, and so on).
The conclusion pleads for ongoing work on understanding identity, for "setting aside the hard encrustations of our differences without falling prey to the illusion that we can all become one" (118). This is well intentioned, but how many contemporary academics need to be convinced not to advocate murderous rhetoric against others, or not to try to "convert" everyone to one religion? Yet if the book aims at a broader, non-academic audience, it should have been written in a different style. Boyarin raises important and interesting questions, but "precisely how the heritage of Christian management of Jewish difference...is related to the...encounter between Spaniards and Indians remains to be specified further" (116).