Nearly five centuries after the first Jesuits set foot on the island of Tanegashima, the history of the encounter between Westerners and Japanese still fascinates numerous scholars and students. Religious aspects of these exchanges, such as the acculturation of Christianity, its understanding by the Japanese, or the discovery of Buddhism by the missionaries, have been at the heart of countless books and articles. However, fathoming the thoughts of the historical actors of the so-called Christian century of Japan (1549–c. 1650) is replete with hurdles, the highest being linguistic. Indeed, the most outstanding studies generally resort to primary sources penned in various Roman languages and different registers of the Japanese language. Thanks to the impressive linguistic skills and intimate knowledge of Christianity and Buddhism of its author, The Samurai and the Cross is a book that belongs beyond doubt to this category.

Antoni Ucerler investigates several dilemmas faced by the missionaries, particularly the Jesuits, while diffusing Christianity in Japan, a land thrown since the end of the fifteenth century into endless wars without any previous ties with the Judaeo-Christian world and monotheism. Two central ideas underlie the twelve chapters: 1) the fathers and brothers of the Company of Jesus were far from constituting a monolithic organization sharing the same approach of Japan's evangelization; 2) the main bone of contention among the missionaries was related to the use of force to propagate or defend the faith. The latter topic is not a new one: Takase Kōichirō 高瀬弘一郎 published in the 1970s his first articles on the Jesuit advocates of a military endeavour in Japan and historians of literature have explored in detail the topos of the “Christian invaders” in the widely read anti-Christian tales of the Edo period (1603–1867). Ucerler is nonetheless the first scholar to analyse this question in a comprehensive (and subtle) manner that takes fully into consideration its intellectual background.

The book is divided into three parts, the first, entitled “Re-inventing Christianity”, concerns the adaptation of Christianity to sixteenth-century Japanese mores and practices. In chapters 1, 2, and 3, the author primarily resorts to two kinds of sources: cases of conscience entrusted to leading theologians in the Iberian empire and a compendium of Aristotelian philosophy and Thomistic theology redacted in Latin by the vice-provincial of Japan, Pedro Gómez (1533–1600), between 1583/4 and 1593, and translated into Japanese in 1595. It was used as a textbook for the Collegio, the “Jesuit College of Higher Studies in Japan”. The analysis of these sources, which covers a large spectre of moral and theological issues as the participation of converts to Shinto–Buddhist rites, the marriages between Christians and non-Christians, the necessity to emphasize the Aristotelian notion of the soul, or the reasons for the late arrival of Christianity in Japan, indicate that the missionary endeavour was continuously evolving to respond to the peculiarities of the Japanese context. The argumentation also aptly shows that Jesuit casuistry could display a certain level of flexibility when needed.

My only reservation here is about the plausible lasting impact of Jesuit teaching on the hidden Christian communities which survived during the two centuries of national seclusion, especially concerning the attitude to adopt under repression. Indeed, the few investigations led by the Nagasaki authorities in the late Edo period and the first reports sent by the priests of the Missions étrangères de Paris in the 1860s reveal that these villagers, who did not have a clear understanding of notions such as apostasy or martyrdom, believed that the strict observance of secrecy was necessary to obtain salvation.

“Re-imagining the enterprise”, the second part, comprises chapters 4–7. It focuses on two topics: the famous accommodation policy of Alessandro Valignano (1537–1606) in Japan; and the recourse to violence to defend a Christian lord or a community under threat or to constrain “pagans” to accept the faith, as happened in several domains in North Kyushu and Kansai. The examination of numerous letters and reports of the “consultations” (consultas) held by the Jesuits in Japan reveals that the Company of Jesus was not united and that the divisions went beyond the nationalities of its members. For instance, ideas such as the dispatch of an Iberian expeditionary force (assisted by Christian Samurais) to China in order to ease the propagation of the faith in this country or the militarization of Nagasaki Port to safeguard the results of evangelization in Japan were finally rejected by Valignano and a majority of Jesuits. Nevertheless, Ucerler demonstrates, first, that these projects, which today seem preposterous (or at least unworkable), were rooted in burning theological debates held within the church since the beginning of the Discoveries, and second, that discussion of the issue among Jesuits continued until well into the seventeenth century.

The five chapters of the last part, “Re-interpreting ‘Reason of state’”, are centred, first, on the impossibility of the Company of Jesus to keeping its distance from the intricacies of Japan's political life and, second, on the main motive beyond the shogunal ban on Christianity in the first half of the 1610s. Ucerler discusses the so-called fear of an Iberian military invasion of Japan supported by the missionaries and their local converts. By relying on a vast array of primary sources, among which some of the principal anti-Christian treatises, he rejects this idea and argues that the shogunate was primarily concerned with the internal unrest Christianity was allegedly provoking. I agree with Ucerler, even though I think more attention should have been paid to the revolt of Shimabara-Amakusa (November 1637–April 1638) and the recent studies that emphasize its religious facet. This bloody episode dramatically impacted the anti-Christian policy of the shogunate and the narratives justifying the use of repression to uproot the “evil teaching”.

Antoni Ucerler's The Samurai and the Cross, a book written in a highly accessible style free of unnecessary jargon, brilliantly guides the reader into the complex intellectual debates provoked by the arrival and propagation of Christianity in Japan. It will soon become a must-read for students and scholars investigating Japanese Christianity or the history of extra-European missions.