Comparative history is liable to arouse certain misgivings. Its practitioners have often tended to exaggerate the similarities between situations divided by space (and sometimes by time). In Bad Christians, new Spains, Byron Ellsworth Hamann compares two episodes investigated in the 1540s by the Spanish Inquisition, one in the area of Oaxaca in Mexico and the other in the vicinity of Valencia in Spain. They were both connected with the behaviour of Spanish Christian landowners and their treatment of labourers who were nominally converted to Christianity but were in fact of another religion. The differences between the two situations, as Hamann himself admits, should not be underestimated. Large though the Muslim (or Morisco) minority in Valencia may have been – it probably amounted to some 30 per cent of the population – the kingdom had been officially Christian since the thirteenth century. The Spanish occupation of Mexico, on the other hand, was a far more recent phenomenon and the native population formed a clear majority. From a theological point of view, moreover, monotheistic Islam hardly bears comparison with the polytheism of the Native Americans.

Hamann is concerned with the direction of the social change in the different worlds which he studies. On the one hand the conversions to Christianity, however nominal they were, undoubtedly suggested a change which would reach into the future, uniting the subjects of Spain in a single Church and a single culture. But the term reducción, much used by Spanish Catholics, also implied change as a restoration of an earlier order. To this there were reactions, especially among the converts who wished to preserve the traditions of their own ancestors and thus to retain a form of continuity expressed in architecture, clothes and burial of the dead. Hamann ranges widely. He draws on art history and anthropology, and has investigated closely not only the documents regarding the cases that he analyses but also the geographical areas (illustrated by photographs). The variety of the fields he explores, as well as the excessively detailed reconstruction of the Inquisition trials with a bewildering number of names, are somewhat confusing, but many of the features that emerge are fascinating.

One of the points that the two episodes have in common is the investigation of the Spanish Inquisition which usually followed the same sort of procedure wherever it was. And it is in connection with the Inquisition that some particularly intriguing aspects come to light. The linguistic problem is striking. Whatever the languages spoken by the various witnesses, whether in Sicily, Spain or the New World, the trials of the Holy Office were ultimately drawn up in Castilian for the benefit of the Suprema in Castile. In the case of the Moriscos of Valencia interpreters from Arabic into Spanish were frequently present. In Mexico the situation was complicated by the many languages. ‘Indigenous witnesses’, writes Hamann (pp. 67–8), ‘would speak in their own language: Dzaha Dzavai, Rain Speech. One interpreter would then translate their words to Nahuatl (the language of the Aztecs, spoken in Central Mexico), and another interpreter would translate from Nahuatl to Castilian.’

Then there is the attitude of the landowners to their labourers and the religions of their labourers. Despite the official image of a Spain united behind the Catholic Church and appreciative of the efforts of the Inquisition to maintain religious orthodoxy, Hamann shows that the relations between the clerical and the secular worlds were by no means always smooth. Many members of the Spanish nobility resented the encroachments of the ecclesiastical authorities in areas which they believed to be answerable solely to their own jurisdiction. One reaction of the landowners was to prevent missionaries from entering their estates. But they went further still. In Valencia they were known to have sanctioned marriages between relatives which would have been prohibited by the Church. On their lands in Mexico they performed (and dissolved) marriages and carried out baptisms. Nor were they only protecting their labourers who had been forcibly converted to Christianity, but on occasion they actually encouraged them to revert to the religion of their fathers. In Valencia this might mean rebuilding mosques which had been destroyed in the anti-Morisco riots, and in Mexico it could extend to the protection of the idols and the religious spaces of the Native Americans. It has often been suggested that the invasion by the landowners of the clerical sphere in such activities as the collection of tithes, and in their protection of the former religions of their labourers, was dictated by economic interests. Hamann's thorough research has proved that this is incorrect. They were certainly eager to retain their honour and prestige, but there is no evidence of their having enriched themselves.

Another interesting point treated in Hamann's study is the extent to which many Muslims believed that they could count on the protection of the pope. Basing themselves on the papal claims to universal religious authority either they themselves, or an Islamic ruler whom they had approached, complained to the pontiff about the infringement of their rights – for example after the fall of Granada when the conditions that the Catholic Kings had promised were violated. The Moriscos, and some of their Christian protectors, expected the pope to guarantee their freedom of worship. In Spain there was far more opposition to the official policy towards the Moriscos than one might expect. At the end of his book Hamann reminds us that the final expulsion from Spain of the Moriscos in the second decade of the seventeenth century ‘was never complete, even officially’. It varied according to the area, but 6–25 per cent of the formerly Muslim population remained.