José de Acosta’s destiny was entwined with the institutional development of the Jesuits to an unusual degree. His parents, probably of new Christian and Portuguese origin, were amongst the order’s earliest and most enthusiastic supporters who sponsored the creation of a Jesuit college next door to their home in Medina del Campos. Apart from José, who was born in the year of the order’s foundation, four other sons joined the fledgeling Society of Jesus at a young age. Andrés Prieto’s new biography follows the stages and frictions of the entangled individual and institutional development across time and space from José de Acosta’s education in colleges in Spain and Portugal (1540–71) to his stay in Peru and Mexico (1571–86) and finally to his last years spent between Spain and Rome (1587–1600). The experience of Peru was decisive, and to this day Acosta’s fame rests on two widely studied works directly linked to it: the missionary manual De procuranda Indorum salute (1588) and the Historia natural y moral de las Indias (1590). The latter was in fact the most widely read and translated book by any Spanish writer in the sixteenth century. Prieto’s aim is not so much to contextualise these works within a history of knowledge, but rather to understand them as the outcome of Acosta’s role both as a theologian and as an ‘imperial agent’. In doing so, he makes (at least) three important points: firstly, that Acosta – despite his extensive travels through Peru, during which he engaged with numerous actors across the social and political spectrum – was never an active missionary himself. Hence, his manual was not the product of a practitioner able to impart what worked best in the field but that of a theoretician who responded to the ideological challenges of the Peruvian context. Secondly, the Historia natural was not the work of a natural historian or natural philosopher but that of a squarely Thomist theologian. Finally, he makes clear that both works addressed Acosta’s major ideological and theological preoccupation, i.e. how to situate the indigenous people of the Americas within the unfolding history of salvation and from here to justify their imperial subjugation by the Spanish.

Fundamental to Acosta’s outlook and to the cogency of his endeavour, according to Prieto, was the discovery upon his arrival in Peru of the trouble and confusion that reigned amongst the clergymen and missionaries active in the vice-kingdom. The root cause was widespread doubts regarding the moral and legal foundations of the empire. Acosta gained deep insight into the ramifications of such debates through his involvement as calificador (1574–6) in the inquisitorial trial of the Dominican friar Francisco de la Cruz. The trial unravelled an exceedingly murky affair that involved a likely case of ‘insanity’, accusations of serious sexual misconduct (rape, solicitation) as well as exorcism and heresy. The reason for the severity of the clamp-down, however, was also political, for La Cruz spearheaded a conspicuous number of theologians who followed the arguments of the Dominican friar Bartolomé de Las Casas. Particularly destabilising were the latter’s denunciations of the pillage of ancient Andean tombs in De thesauris (1562) and his Treatise of the twelve doubts (1564), which claimed that Spanish rights were limited to preaching the Gospel and hence that restitution should be made of the dominion of Peru to the descendants of the last Inca. Worryingly, Jesuits, and even the provincial of Peru, were also caught up in the affair. The so-called Lascasistas were no mere doubters; they acted on their convictions, for instance by withholding absolution for encomenderos in confession and demanding acts of material restitution to the exploited indigenous population. It was incendiary stuff that undermined the moral and political order. No wonder, therefore, that viceroy Francisco de Toledo was determined to stamp out the Lascasistas and suppress Las Casas’s writings.

There was, however, yet another query that surfaced in the course of the La Cruz trial which, according to Prieto, became one of Acosta’s core life-long concerns, from De instauranda, which he began writing during the trial, to the Historia natural many years later. The problem at hand was whether indigenous and black enslaved people lacked the capacity, as La Cruz and his followers claimed, fully to understand and penetrate the mysteries of the Christian faith and whether therefore ‘a simple belief’ in one God should be considered sufficient for their salvation. Acosta rejected this suggestion and insisted instead that the intellectual capacities of the indigenous were not at all inferior; it was not a question of nature but of culture or acculturation, he argued. The indigenous peoples were rational human beings, similar to the Romans or other pagans, whose judgement was impaired on account of ignorance. What was needed was teaching and education, for which Acosta set out the adequate strategies in his mission treatise.

Another controversial question, and an evergreen in all missionary contexts, was the compatibility of indigenous rituals with Christianity. While Acosta did not initially support their blanket ban, he did not favour strategies of accommodation either, and as time went on, he became increasingly opposed to preserving native ritual practices. His position on such questions was anchored both in his humanist trust in the power of education and in his theological conviction and belief in the salvific necessity of the sacraments. This was the point where missionary questions and the justification of empire became deeply entangled and from where he went on to develop the ideological foundations of his Historia natural y moral.

There was no doubt in Acosta’s mind that the evangelisation of the Americas was part of God’s plan and that colonial subjugation served it; it was, as Prieto puts it, ‘a spiritual imperative and not just a political fait accompli’ (p. 234). Comparing the Americas to an ‘ugly daughter with a rich dowry’ Acosta even believed that God astutely had factored in human greed in order to attract the Spaniards to conquest, which in turn laid the economic and political foundations for the missions. Consequently, Acosta considered violent colonial policies such as the forced relocation of population or forced labour as necessities without which the missions could not prosper. In this sense, certainly, Acosta was an agent of empire as Prieto contends. None the less, his narrative also delivers ample evidence regarding the tensions in the Jesuit’s relationship with the viceroy and other imperial agents in the field. There were many instances of conflict, as both sides had divergent priorities. While for Acosta the State was in the Church, for the viceroy, clergymen should serve the state and he was not prepared to make exceptions for the Society of Jesus and their privileges.

One area in which Acosta’s success was more clear-cut was his involvement in the third Council of Lima (1582–3), in which he acted as the leading theologian drafting memoranda, reports and the final edicts. Indefatigable, and to support the implementation of Tridentine standards, he also authored two catechisms, a handbook for confession and a sermon collection. His confession handbook is of particular interest. Here, Acosta proposed techniques of intense preparation for confession and for this purpose even allowed using quipus as a supporting mnemonic tool for indigenous people. Moreover, he emphasised the importance of confessing the ‘sins of the heart’. Indeed, as Acosta remarked in his Historia natural, while the Incas entertained practices of atonement that resembled the sacrament of penance, at closer inspection the two differed starkly. The indigenous practices, he believed, were mainly concerned with exterior acts and offence to the community, not with the individual and their offence to God. It was a poignant reminder that similarities could be deceptive, which is why he considered accommodationist strategies as potentially slippery and dangerous.

Prieto discusses Acosta’s preoccupation with the sins of the heart as a translation of recent Tridentine norms and Jesuit ideas. Yet. as John Bossy argued many years ago, the interiorised interpretation of the sacrament did not follow so much from new Tridentine directives but from much older, late medieval spiritual developments. Moving away from virtue ethics, these focused on human intentions and on the relationship between the believer and God, which in turn was exactly what was at the heart of many post-Tridentine reformers’ as well as the Jesuits’ pastoral concerns. When Acosta returned to Spain, his reputation rested on his achievements in consolidating the Jesuits’ position in Peru and on his contribution to the consequential third Council of Lima. Back in Europe, he went on to publish De instauranda and the Historia in quick succession.

Yet, despite these achievements, the homecoming and the last decade of his life were trying and at times disappointing. Acosta was increasingly torn between his loyalties to the court in Madrid, the papal curia, the Spanish Jesuits and the Jesuit general. Tensions between all parties increased during the so-called memorialista crisis when a substantial number of Spanish Jesuits accused their general in Rome of tyranny. Although Acosta was critical of the memorialistas and their conduct, he was also sympathetic to their calls for a less centralised organisation of his order. In 1593, when the Spanish Jesuits with Philip ii’s support forced the Jesuit General Acquaviva to call the Fifth General Congregation, things came to a head, and Acosta, as Spanish envoy, found himself in the cross-fire. The congregation ended with a defeat of the memorialistas, who were expelled with immediate effect; moreover, suggesting that the rebellious elements were linked to New Christian elements, General Acquaviva and his followers imposed new rules which henceforth banned members of Jewish descent. Acosta, to his credit, voted against it, but he must have felt let down in more than one way by the religious order to which he had dedicated his entire life.

In the end, the demands of competing empires, so to speak, could not be reconciled without contradictions. The strict chronological order in which Prieto tells the story of Acosta’s life leads to some repetition, especially in the latter part of the work where the love of detail at times overtakes the spirit of synthesis. Yet his portray of Acosta and the worlds he inhabited vividly conveys that the Jesuits were far less ideologically coherent than is often believed. Acosta’s life and his increasing isolation in old age illustrate how such ideological differences and divergences unfolded over time and intersected along regional as well generational lines.