This is a unique and curious book. Using a dictionary format, the authors deal with a long list of religious concepts, comparing each as it was considered in fifteenth-century Spain, precontact Mexico, sixteenth-century Spain, and sixteenth-century Mexico. The concepts listed, 140 of them, are an odd lot: some clearly come from Christianity (baptism, communion, crucifix, original sin, and the like) while others come from the religion of the Mexica (arrow, bird, eagle, sacred bundle). Others seem to be vague enough to allow for comparison (creation, dance, death, flower).

The authors have used a wide selection of secondary sources to come to grips with their topics. In many ways, these brief essays serve as a tool to enter a deeper discussion of various aspects of the two religions. These pieces should not be considered as definitive statements on the topics. There is just too much to consider on each topic, and the essays mark only a small beginning. Indeed, each topic could support several books. Unfortunately, it is as if the reader were caught in an example of “double mistaken identity,” a term coined by James Lockhart. For example, the Mexica had a ritual that Spaniards believed was a cognate of baptism, and thus it was evaluated by them from that theological perspective. Similarly, the Christians worshipped a deity who was executed and underwent an apotheosis; the Mexica evaluated it in terms of their own religion's emphasis on reciprocity and balance. Neither side really understood what the other was about.