Infidelitas

Definition and Context

The concept of infidelitas used by Salamancan jurists and theologians takes its basis from the systematic exposition Thomas Aquinas provided in STh II-II, q. 10 —De infidelitate—. With Thomas, the School of Salamanca defines infidelity primarily in a negative way, as the vice opposed to the faith (STh II-II, q. 10, art. 1). Nevertheless, not every infidelity could be considered to be sinful, given that a purely negative one, possible in the case of persons who had never even heard of Him, was clearly not reprehensible and had to be understood instead as a punishment resulting from the original sin. Infidelity as a vice (true infidelity) includes therefore the kind of actual partial or total refusal of the Christian Truth (infidelitas secundum contrarietatem ad fidem, cf. Vitoria, Confessionario (1562), pars 2 cap. 2, paragr. "¶ Si se aparro…") that we find in Jews or Muslims, and in Christians deliberately distanced from faith (apostasia), refusing to believe something related to the faith (haeresis) or intentionally casting doubts on it.

The Thomistic approach to infidelity opposed other theological medieval and early modern perspectives, according to which Christian Truth had already been preached all around the world by the Apostles, a fact that -if granted- made infidelitas inexcusable as a whole (cf. Báñez, De fide, spe et caritate (1584), q. X, a. I, 557-558). This perspective notably benefited the pagan populations of the American colonies, judiciously differentiated from those infidels who actively and consciously rejected the Christian faith, whose goods and jurisdictions could be legitimately taken away by Christians.

The historical encounters with infidel populations in the Americas also motivated the revision or clarification of Thomas's definition of infidelity. Speaking in a very general and synthetic way, Aquinas had stated that the sin of infidelity could also consist in the refusal of someone to hear the Faith or in his contempt for it (STh II-II, q. 10, a. 1 [Editio Leonina, p. 78]). Since royal jurists and theologians had appealed to this vague definition to justify the wars, enslavement and plundering of many American and Asian natives after the failure of a single superficial and purely formal attempt to inform them about the Christian Faith¹1 The Spanish Requerimiento, written by Juan López de Palacios…
The Spanish Requerimiento, written by Juan López de Palacios Rubios, is perhaps the best known and most infamous example of this kind of theological and juridical chicanery., Salamanca commentators of the Summa such as Báñez²2 Báñez in this respect is quite representative of the positio…
Báñez in this respect is quite representative of the positions of the School and its consolidation, insofar as he summarized, developed and prepared for publication previous manuscripts commentaries of Vitoria, Soto, Cano, Corpus Christi and Medina. See García Cuadrado, José Ángel , “La obra filosófica y teológica de Domingo Báñez”, Anuario de Historia de la Iglesia 7 (1998), 209-229, spec. p. 213. felt themselves compelled to clarify that, in the absence of some supernatural means -such as an internal illumination caused by God (Báñez, De fide, spe et caritate, q. X, a. I, 559)- that would be hard to verify, a peaceful and appropriate predication by honest and competent missionaries (proficient in the Native languages and able enough, for example, to persuade the infidels by natural reasons that the Christian doctrine could regulate life better than any other) was necessary in order to overcome negative infidelity (Báñez, De fide, spe et caritate, q. X, a. I, 578). Moreover, if not convinced of the greater credibility the Gospel had vis-à-vis any other system of beliefs, non-Christians could be considered excused from the sin of infidelity (Báñez, De fide, spe et caritate, q. X, a. I, 579), as it had happened with most of the inhabitants of the Western Indies (Báñez, De fide, spe et caritate, q. X, a. I, 578). These new nuances were also in line with the missionary spirit prevailing in 16th and 17th centuries, and it was emphatically underlined in the pragmatic theology divulged in manuals for priests and confessors working overseas (cf. Acosta, De procuranda indorum salute, Libro V, Cap. IV, Vol. II, págs. 218-219).

The tradition also considered that infidelity is the greatest sin by its nature and consequences (the condemnation of the soul, given that without faith there is no salvation). It involves breaking the first commandment by opposing, hating or culpably ignoring God. Besides, infidelity inclines men to various other sinful beliefs, distorted, superfluous or pernicious ways of worshipping God (cf. Azpilcueta, Manual de Confessores y Penitentes (1556), cap. 11 paragr. "¶ Lo segundo qu…"). In the rationalistic Thomistic framework, for a belief to be considered sinful, the individual holding it has to be conscious about him or her holding an affront to God or to the Holy Catholic Faith. That would be the case of the Heretic. But this kind of stubborn reluctance was not the only infidelity considered as a sinful. Those who, having reached the age of reason and having discretion, did not do enough to know the mysteries of Christ and the Trinity, essential dogmas of the Christian creed, also were guilty of the sin of infidelity. Infidels of this kind ignore the Faith by will or laziness (ignorantia crassa sive supina) and could not therefore be excused for their infidelity, clearly sinful and vitious (Azpilcueta, Manual de Confessores y Penitentes (1556), cap. 23 num. 44). It follows from previous statements, that the definition of infidelity presupposed and, at the same time, complemented, a complex theoretical framework in which the concept of ignorantia and a wide family of subconcepts derived from this central notion play a key role.

In popular and not technical writings, concepts such as superstitio and idolatria are often used as synonyms for infidelitas. Strictly speaking, they are by no means identical concepts: while infidelity is defined in a purely negative way (the absence of faith), superstition consist in offering Divine worship to beings other than God or offering worship to God in an improper manner. With regards to the sin of idolatry, it involves the active offering of reverence to false gods (whether imaginary or deified people, animals or objects).

While, from a theoretical perspective, Salamanca scholastics added only slight nuances to Thomas's definition of infidelity, explaining with supplementary technical terms the kind of opposition to the faith the Doctor Angelicus had referred to -a repugnantia formali & expressa vel interpretatiua (Báñez, De fide, spe et caritate, q. X, a. I, 559)- authors of pragmatic literature focused on the differentiation between the various kinds of superstitious beliefs to which the vice of infidelity inclined men and on the clarification of the proper way in which any kind of superstitious belief had to be judged and eradicated. On their own, some of the most prominent Salamanca theologians discussed burning contemporary topics such as the way in which the countless number of Pagan peoples recently discovered in the Americas should be integrated within the traditional conceptual and normative framework on infidelity.³3 With his Libellus circa dominium super indos, presented befo…
With his Libellus circa dominium super indos, presented before the Junta of Burgos in 1512 , Matías de Paz had opened a debate in which Francisco de Vitoria, Domingo de Soto and other well-known figures of the School of Salamanca made major interventions. Cf. José Luis Egío, “Matías De Paz and the Introduction of Thomism in the Asuntos De Indias: A Conceptual Revolution”, in: Rg 26 (2018), 236-262, DOI:10.12946/rg26/236-262.

Given the complex historical background behind the notion of infidelitas, the diversity of literary genres making use of the concept in the early modern period, the specific goals of each genre and, especially, the growing importance of this topic in the age of the Protestant Reform and the American discoveries, it is difficult to circumscribe with precision its context of use in the writings of the School of Salamanca. We find mentions to the notion for instance in rather theoretical debates about how infidelity relates to other vices, a topic of interest for the history of theology and ethics. From a perspective of juridical and political language, however, debates about how infidelity affects the moral capacity of an agent, what the responsibilities of a Christian towards infidels are, about other pressing contemporary social and political issues concerning the juridical status of infidels, or about the way in which missionary policies should address the different kinds of infidels, figure among the most interesting and controversial ones.

Infidelitas in Ancient and Medieval Literature. Meaning and Uses of the Concept

The concept of infidel emerges in parallel to the awareness of belonging to a new ἐκκλησία during the Paleo Christian era. The Apostle Paul gave the Christian flock the first instructions regarding social intercourse with Jews and Gentiles, the most appropriate ways to instruct them about the Faith, the kind of obedience Christians had to pay to temporary Pagan authorities, etc. In 1 Corinthians 5-12, we find a first general expression used to designate every non-Christian: those who are outside [the community, the Church]. From its very beginning, the reference to infidels clearly had a jurisdictional character: as Paul recognized, the conduct of those outside the Church was beyond his control, that is to say, only God could judge them. Inasmuch as, from Vitoria on,⁴4 Cf. Vitoria, Relectiones Theologicae XII (1557), vol. 1 rele…
Cf. Vitoria, Relectiones Theologicae XII (1557), vol. 1 relect. "De Indis prior"…" art. 29 the Salamanca scholastics opposed the direct potestas over infidels that some previous theologians and canon lawyers had granted to the Pope and ecclesiastical authorities, Paul's designation and criterion would appear recurrently as authoritative source (cf. also Covarrubias, Diego de, Explicatur regula ‘Peccatum', De regulis iuris, in 6, a restitutione facienda quomodo quis excusetur, in: id., Opera Omnia, Tom. 1, Genève, 1679, 622-696; Molina, Luis de, De iustitia et iure, q. 40 [De bello]).

The most ancient sources of Canon Law in Spain, dating from the Council of Elvira (around 302 C.E.), show also the effort of the ecclesiastical hierarchy to separate Christians from infidels, and to develop specific approaches for the regulation of the convivencia with Jews and Pagans. In this early period numerous prohibitions meant to keep Christians away from the contamination of Jews, Pagan and heretics (prohibiting marriage between Christians and Jews, the common table, the participation of Christians in sacrifices and offerings to idols etc.).

Much of the theological doctrine and canonical prescriptions about infidelitas synthetized in the great authoritative compilations of the Middle Ages (Corpus Iuris Canonici, ca. 1130-1317; Peter Lombard's Libri Quattuor Sententiarum, ca. 1223-1227; Thomas Aquinas provided in Summa theologiae, ca. 1274 took their basis from theological debates dating back from the Paleo-Christian context and later revisited and updated in a new context characterised by the expansion of the Islam and the persistence of Judaism, confined in isolated communities. Insofar as the 16th century implied a Pagan comeback, apostolic sources and Church Fathers such as Augustine of Hippo, who had addressed almost every open question in Late Antiquity Church, experienced a regain of interest. For example, Augustine's consideration that infidels were incapable of true virtue, good actions and legitimate dominium, because virtues and dominium were gifts of God and resulted from divine grace -not from human nature and will- was still considered a fundamental authority in the Salamancan juridical writings (cf. Solórzano, Juan de, De Indiarum iure II, cap. 10, § 24-26).

Thomas Aquinas was the medieval author that most influenced the Salamanca reflection on infidelitas. In STh II-II, q. 10 —De infidelitate—, there are twelve articles touching most of the issues addressed by later authors. Even for the discussion of unprecedented epochal dilemmas, Thomas's doctrine played the role of a mandatory framework with which any valid solution had to be articulated. Articles one to six, rather theoretical, offer a systematic definition and typology of infidelity, reflecting about whether infidelity it is a vice, in which faculty it resides, whether it is the greatest of vices, how it affects the capacity to act morally, how many species of infidelity there are, and how these can be ranked. In some of these theological speculations we find the point of departure of the debates on practical issues that Thomas -and following him, Salamanca scholastics- approached in subsequent questions.

In article five, Thomas distinguished between several types of infidelity according to the different ways in which the truth about the triune God had been rejected: either it had never been professed by the subject beforehand (Pagans), only confessed in figura (i.e. in the prophecies of the Old Testament, which holds for the Jews), or, finally, in its actual and manifest truth (i.e. in the New Testament, which is the case for heretics).

Articles seven to twelve deal with many practical questions concerning the living together of Christians and infidels and the legal-political status of the later. The main issues discussed by Aquinas were the following: how pious people should behave towards infidels, whether a Christian should debate matters of religion or cooperate with them, whether they should be forced to assume Christianity, whether they could be tolerated in positions of authority over Christians, whether their religious rites could or should be tolerated, and whether their children should be baptized regardless of the parents' will.

The legitimacy of infidels' dominium (private and public) was a topic of particular interest to Thomas (article twelve). While Christians should not permit that an infidel becomes ruler over Christians (which harbours the dangers of scandalum or periculum fidei), this does not invalidate the pre-existing authority of an infidel ruler. In accordance with article four, which stated that even though they may be affected by original sin and devoid of Faith, non-believers have still a certain capacity for reason and for the moral good, Thomas admitted as possible the existence of reigns and republics ruled by infidel authorities according to natural law. This authority —being an expression presumably of natural reason— is not invalidated by divine law (cf. article 10, resp.). For the Salamanca authors revisiting the issue and updating Thomas's conclusions, a very important authoritative point was also the condemnation of the contrary position by the Council of Constance in 1415 (cf. Báñez, De Iure et Iustitia Decisiones (1594), praef. paragr. "PRO decisione h…").

Despite his concessions to infidels, Thomas had remained quite ambiguous: although valid, infidels' dominium was of a precarious condition. In fact, it can be done away at any time by decree of the Church, that as Thomas recognized, had not a fixed position on this matter, transferring infidels'' goods and jurisdiction to Christians only sometimes.⁵5 Cf. Ruby, Jane, “The Ambivalence of St. Thomas Aquinas' View…
Cf. Ruby, Jane, “The Ambivalence of St. Thomas Aquinas' View of the Relationship of Divine Law to Human Law”, in: The Harvard Theological Review 48:2 (1955), 101-128. Given the violence of the wars engendered with theological alibis in the recently discovered America and the counterproductive effects they had, compromising the evangelisation project just begun, Vitoria and other Salamanca authors focused later on closing the gaps and remediate the vagueness of Thomas ideas on infidels' dominium.

In 15th and early 16th century approaches to infidelity, such as the ones of Antoninus of Florence -Summa Theologica (1477), Titulus XII, De infidelitate- and Sylvester Mazzolini of Prierio -Summa Sylvestrina, (1514-1515)- significant differences to Thomas can hardly be found. There are however some nuances that should be noted and would become important reference points for Salamanca's second scholasticism. For example, Antoninus approved of a couple of permissible softer incentives (presents, reduction of tributes) for conversion,⁶6 Cf. Antoninus Florentinus, Summa Theologica (1477), Pars Sec…
Cf. Antoninus Florentinus, Summa Theologica (1477), Pars Secunda, tit. XII., col. 1148. which would be revaluated in the light of the huge American and Asian indoctrination processes. On his own, Sylvester discussed at length juridical issues such as the expropriation of infidels' possessions -concluding that it could be done only by private authority if there were clear links to specific crimes, different from infidelity itself- and the capacity of infidels to serve as a witness in legal trials, which he denied.⁷7 Sylvester Mazzolini of Prierio Summa Sylvestrina, Pars secun…
Sylvester Mazzolini of Prierio Summa Sylvestrina, Pars secunda, tit. Infidelitas, pp. 36-7.

Even if Vitoria had often been seen as the first Salamanca scholastic, who, playing a pioneering role, reevaluated ancient and medieval sources on infidelitas and developed new trends of interpretation aimed to solve with equanimity the new historical dilemmas entailed by the discovery of new, Pagan peoples in the Americas, earlier Salamanca masters also got deeply involved with similar questions. A deep theological and juridical reflection accompanied, in fact, the dynamic of expansions into the 'infidel' Africa initiated by Castile and Portugal in the 14th century.⁸8 Egío, José Luis; Birr, Christiane, “Before Vitoria: Expansio…
Egío, José Luis; Birr, Christiane, “Before Vitoria: Expansion into Heathen, Empty, or Disputed Lands in Late Mediaeval Salamanca Writings and Early 16th-Century Juridical Treatise”, in: A Companion to Early Modern Spanish Imperial Political and Social Thought, ed. by Jörg Tellkamp, Leiden, Brill, 2020, pp. 53-77. Furthermore, the Spanish monarchy had at its disposal accurate and comprehensive opinions about the peculiar infidelity found in the nation of the Indians since, at least, the Junta de Burgos (1512). In one of the treatises presented to this Junta, De dominio Regum Hispaniae super Indos, written by the Salamanca theologian Matías de Paz, Native Americans' infidelity is defined and classified from a theological and juridical point of view. Those people ad quorum notitiam forte nondum venit fides nostra, (De Paz, Matías, De dominio Regum Hispaniae super Indos (2017 [1512]), 86–88), living in lands quae nunquam fuere subjectae iugo Salvatoris nostri (De Paz, Matías, De dominio Regum Hispaniae super Indos (2017 [1512]), 151) are consciously and reasonably put apart from other kind of infidels confronted by Christian Church along its history.

De Paz’s juridical classification between different kinds of infidels according to the lands they inhabited, which remained in manuscript form until the 20th century, was popularized by Cajetan in his commentary on the Summa Theologiae (1508-1523). Addressing II-IIae, q. 66, art. 8, he openly corrected Thomas who, following Augustine, had considered as non-sinful the plundering of infidels' goods. For Cajetan it was necessary to distinguish infidels a) subditi de facto et de iure Christianis, such as Jews, Moors and Heretics living under the dominion of Christian princes,⁹9 These could be legitimately deprived of goods, servants and …
These could be legitimately deprived of goods, servants and even women and children, as it is recorded, in fact, in Decretum Gratiani, Distinctio LIV, Cap. XV, quoted by Cajetan and b) subditi de iure et non de facto principibus christianis, who usurped lands once under Christian jurisdiction, such as Turks and Saracens - both of them susceptible to be deprived of their goods without mercy-,¹⁰10 Infidels that were non solum infideles, sed hostes Christian…
Infidels that were non solum infideles, sed hostes Christianorum could be fought and plundered without mercy. from a third kind of infidels, c) who nec de iure nec de facto subsunt secundum temporalem iurisdictionem principibus christianis, living in lands which neither belonged to the Roman Empire, nor had once been under the jurisdiction of any Christian prince. This third category of infidels, to which the Pagan peoples being discovered in the Indies belonged, could not be deprived of their goods in the absence of valid titles other than their infidelity (aggressions, blasphemies or any other kind of iniuriae).¹¹11 Vio, Tommaso de (Cajetanus) (Thomas Aquinas), Summa theologi…
Vio, Tommaso de (Cajetanus) (Thomas Aquinas), Summa theologiae cum commentariis Thomae de Vio Caietani Ordinis Praedicatorum, Parte II-IIae, q. 66, art. 8, Tomus Nonus, pág. 94. The introduction of this juridical distinction between different kinds of infidels, taken up by many 16th and 17th century authors, was so important that in his Historia de las Indias, Bartolomé de Las Casas considered it as the contribution that dio luz a toda la ceguedad que hasta entonces se tenía.¹²12 Las Casas, Historia de las Indias, Tomo III, Cap. XXXVIII, p…
Las Casas, Historia de las Indias, Tomo III, Cap. XXXVIII, p. 143. From his first work on, Las Casas differentiated infidels according to the criteria of Cardinal Cajetan (Las Casas, De unico vocationis modo [Obras completas, Vol. II, Madrid, Alianza, 1990, pp. 575-576]).

De Paz's and Cajetan's pioneer accommodations, show that, in light of the new phenomena and moral dilemmas arising with the American discoveries, which marked the starting point of modernity, the medieval concept of infidelity and its internal typology began to evolve little by little, trying to provide more differentiated and nuanced answer to the specific quaestiones of the time.

Infidelitas in the writings of the School of Salamanca

Even if most of the texts of the prominent Salamanca masters Vitoria and Soto do not focus on the question of infidelity —that is, not at first glance-, the sheer extent of their discussions about infidelitas, no less than their importance for subsequent thinkers, suggests that both of them are thinkers of extraordinary relevance in this question.

As the very title of Vitoria's Relectio de Indis suggests, the central phenomenon that the question of infidelity was now seen as addressing, was the existence of entire societies that had never had contact with the Christian faith and that had —by whatever means and by whatever right— come under the jurisdiction of Christian princes.

Infidelitas and the moral capacity of an agent

In Vitoria's Relectio de eo ad quod tenetur homo cum primum venit ad usum rationis (1535), we find the moral theological foundation of the specific Salamanca approach to infidelity, singularized vis-à-vis ancient and medieval sources by the key role played by the concept of natural law. The central question Vitoria addresses in this relectio, written some years before the more famous Relectio de Indis (1539) is how infidelity affects the moral capacity of an agent. To clarify if -against the authority of Augustine of Hippo- infidels could be considered capable of good actions and of exerting a dominium respectful with regards to natural law, was decisive in order to determine the way in which the recently discovered infidels would be brought into Christianity: little by little, and with a certain respect for their natural princes, probably good rulers, or abruptly and without any kind of considerations for their supposedly wicked superiors.

For Vitoria, an action corresponding to the natural recta ratio uses of things —as God intended them to be used— should be understood as implicitly corresponding to God’s intentions. In other words, the rational correspondence of an action to its concrete objects and circumstances refers it implicitly or indirectly to God, regardless of whether or not the agent is aware of it. Such actions are carried out just as God had intended; hence, they are virtuous, and this applies as well to the agents performing them, even if they are infidels. Liberum arbitrium and dominium sui actus, necessarily and sufficiently constitute the person as a moral agent. And while it is through this capacity that mortal sin becomes possible, the same holds true for virtue, thus enabling any person -even infidels- to lead a life that is pleasing to God (Vitoria, Relectio de eo ... (1535), art. 14, in: id. Relectiones Theologicae XII (1557), vol. 2).¹³13 For a complete exposition of Vitoria’s ideas about a moralit…
For a complete exposition of Vitoria’s ideas about a morality based on natural reason, see Spindler, Anselm, Die Theorie des natürlichen Gesetzes bei Francisco de Vitoria: warum Autonomie der einzig mögliche Grund einer universellen Moral ist, Stuttgart, Frommann-Holzboog, 2015. For Vitoria then, even if it was difficult that an infidel who was (guiltlessly) ignorant of Christ could live a life free from sin -lacking the precious guiding light of the Gospel-, the possibility could not be strictly excluded. Inasmuch as natural law had been written by God in the heart of every rational being, Faith, even if important, was not indispensable to live a good life, and even infidels trying to live according to their innate insight into natural law could potentially do it.

Justification of infidels?

For Soto, who, in 1545-47, participated in the debates on original sin, grace and justification at the Council of Trent, and in 1547 published his influential writing De natura et gratia (Venice, Giunta, 1547), the determination of the role of Divine grace for virtuous behaviour and for access to God’s grace were also of great concern. In agreement with Vitoria, Soto didn't exclude the possibility of a morally virtuous infidel. Likewise, later Salamanca scholastics agreed unanimously with this position,¹⁴14 See a detailed list of many of the Salamanca authors who sha…
See a detailed list of many of the Salamanca authors who shared this view in Solórzano, De Indiarum iure II, cap. 11, § 50-52. Among others, Solórzano mentions Bartolomé de Medina, In II-II, q. 109, art. 2, vers. ad 5 respondetur; Pedro de Aragón, In Secundam secundae diui Thomae doctoris Angelici commentaria, q. 10, art. 10, vers. His tamen non obstantibus; Gregorio de Valencia, De Legibus. Commentaria Theologica et Disputationes in Summam D. Thomae Aquinatis, disp. 1, quaest. 10, puncto 2; Diego de Covarrubias, Cap. Alma mater I parte, § 4, n. 7; Juan de Azor, Institutiones morales, Lib. III, Cap. 29, q. 6; et lib. IV, cap. 25 q. 14; Pedro de Lorca, In II-II sect. 1, disp. 35; Luis de Torres, De fide, spe et caritate disp. 50, dub. 3, coll. 628 ss.; Suárez, Tractatus de fide theologica (1622), De fide, disp. 17, sectio 3, ex n. 2. which was also officially sanctioned by the Council of Trent (sess. 6, De iustificatione, c. 7).

In indirect connection with the general debates on grace and justification, an important collateral controversy, related again with the specific dilemmas raised by the discoveries in the New World, was raised. Could (some kind of) infidels be justified without baptism and lacking an explicit knowledge of Christ?¹⁵15 Baptism, the sacramental formal act that makes an individual…
Baptism, the sacramental formal act that makes an individual a member of the Church until the end of his or her life, was considered the essential element for the distinction between fidelis and infidelis in many early modern theological vocabularies, such as the Vocabularium theologie of the German Catholic scholastic Johann Altenstaig, who defined the infidel as jeder, der nicht getauft ist; cf. Meyer, Christoph, “Nichtchristen in der Geschichte des kanonischen Rechts. Beobachtungen zu Entwicklung und Problemen der Forschung”, in Rg 26 (2018), p. 143, DOI:10.12946/rg26/139-160. For Vitoria and Soto, it was very problematic to accommodate the clearly majoritarian position of the theological tradition -extra Ecclesiam nulla salus- to what some of their Dominican brothers, missionizing in the Western Indies had experienced: entire populations of Pagan infidels, removed from the Christian faith since centuries, but apparently living in a state of innocence and completely alien to sin.

Trying to open a door for the salvation of this new kind of blameless infidels, Vitoria and Soto dared to correct the traditional position of the Church and introduced a significant nuance: in the case of the infidels of the New World, ubi non erat depravata natura vitiorumque caligine obducta (Soto, De natura et gratia, f. 143r), it could have been possible that some virtuous individuals and peoples, respectful of the principles of the natural law, had gained salvation without having been evangelized and baptised. Overstating, or forcing a little, previous statements by Thomas, Vitoria determined in his Relectio de Indis that this kind of good infidels were illuminated by God about the name of Christ and could then be justified without baptism (Vitoria, De Indis prior (1539), art. 33, paragr. "¶ Vnde dico, qu…, in: id. Relectiones Theologicae XII (1557), vol. 1).

In his Commentary on the Fourth books of the Sentences (first printed, 1557-60), Soto takes up the question of what kind of sin infidelity is, whether sinners are to be baptized and if they can reach salvation without baptism, leading to a higher level of abstraction the practical dubium evaluated by Vitoria in De Indis. Soto distinguishes between the acceptance of the Christian faith being necessary in order to reach salvation, and it being obligatory by means of a special precept. With regard to the first point, he holds that implicit faith, i.e. obedience to natural law and deliberation according to natural reason, is inviting the divine support (ops) that is necessary anyway in order for a human being to facere quod in se est, which, in turn, is sufficient for salvation.¹⁶16 Cf. Soto, In IV Sent. (1581), dist. 5, q. 1, art. 2, p. 247 …
Cf. Soto, In IV Sent. (1581), dist. 5, q. 1, art. 2, p. 247. With regards to the second point, he insists that after the coming of Christ, all humankind is, indeed, obliged to accept the Christian faith. Nevertheless, some of those who fail to comply with this obligation are excused by virtue of invincible ignorance, and hence the lives they might be able to live virtuously, relying on implicit faith and natural law, need not really be tainted by their failure to comply with that special precept.¹⁷17 Again, cf. Soto, In IV Sent. (1581), dist. 5, q. 1, art. 2, …
Again, cf. Soto, In IV Sent. (1581), dist. 5, q. 1, art. 2, p. 247.

Despite the high reputation Vitoria and Soto enjoyed as masters of a whole generation of theologians issued from the University of Salamanca, their resolution of this problematic issue met the resistance of later Salamanca authors who, being active in the ambitious missionary enterprises initiated by the Spanish and Portuguese Crowns, considered such a position to be a discouraging factor. That was the case for Acosta, who in his De procuranda indorum salute, stated bitterly: Y en realidad y verdad, si sin conocimiento de Cristo puede haber salvación o justificación, entonces no vale la pena predicar a Cristo y es inútil enviar a los Apóstoles al mundo entero. Also, Azpilcueta, colleague and admirer of Vitoria and Soto,¹⁸18 Throughout his Manual de Confessores y Penitentes (1556) , A…
Throughout his Manual de Confessores y Penitentes (1556), Azpilcueta regularly appeals to Vitoria and Soto as solid supporting authorities in many issues. See, for example, on the debates on contrition (cap. 1 num. 36). sourly condemned this resolution in his Manual de Confessores y Penitentes, considering it to be contrary to the mandamiento de bien creer en Dios and a mortal sin (Azpilcueta, Manual de Confessores y Penitentes, cap. 11, num. 17). Acosta's qualification was even harder: even if such an opinion arose from the well-intentioned attempt of not closing cualquier posibilidad de ir al cielo (…) a la infinita cantidad de personas que en este Nuevo Mundo estuvieron privadas de la luz del Evangelio durante tantísimo tiempo, Vitoria and Soto were responsible in this case of a great and even heretical mistake, since no hay cosa más contraria a la fe que decir que sin la fe puede salvarse algún hombre (Acosta, De procuranda indorum salute, Vol. 2, Libro V, Cap. III, págs. 190-191). The debate about this hypothetical possibility of infidels' salvation outside the Church, having had access to Faith only by an internal illumination shows well the nature of the School of Salamanca: Vitoria, Soto, Azpilcueta and Acosta had a common approach to the topic; they considered problematic the same specific issues; even if belonging to different generations,¹⁹19 Vitoria died in 1546 , when Acosta was still a six-year-old …
Vitoria died in 1546 , when Acosta was still a six-year-old child. religious groups²⁰20 While Vitoria and Soto were Dominican friars, Acosta was Jes…
While Vitoria and Soto were Dominican friars, Acosta was Jesuit and Azpilcueta a secular clergyman. and faculties²¹21 While Vitoria , Soto and Acosta taught Theology at the Unive…
While Vitoria, Soto and Acosta taught Theology at the University of Salamanca and/or at the Colleges of their respective orders, Azpilcueta taught Canon Law at the Universities of Salamanca and Coimbra., they shared a similar argumentative style, evaluating arguments pro et contra, before coming to a certain conclusion; lastly, they made appeal to a common "fingerprint": their texts resorted to almost the same medieval and contemporary sources, discussing them in a different order.²²22 On the idea of "finger prints" as a key element giving a com…
On the idea of "finger prints" as a key element giving a common identity to the Salamanca scholastics, see Scattola, Merio, “Konflikt und Erfahrung: Über den Kriegsgedanken im Horizont frühneuzeitlichen Wissens”, in: Justenhoven, Heinz-Gerhard, Stüben, Joachim (eds.), Kann Krieg erlaubt sein?: eine Quellensammlung zur politischen Ethik der Spanischen Spätscholastik, Stuttgart, Kohlhammer, 2006, p. 20. A reappraisal and further development of these ideas in Duve, Thomas, “The School of Salamanca: a case of global knowledge production”, in Duve, Thomas, Egío, José Luis, Birr, Christiane, The School of Salamanca: a case of global knowledge production?, Leiden, Brill, 2020. However, in spite of all these points in common and despite the use of the same "working tools", they could arrive to diametrically opposite conclusions, showing an open disagreement difficult to find in other master-disciples relationships.

Infidelitas and dominium

In the juridical and political theory of the School of Salamanca, there is a common agreement -following the line of interpretation of Thomas, STh II-II, q. 10, a. 12, provided by Vitoria in De Indis- that infidelitas does not preclude dominium (Vitoria, De Indis prior, paragr. "¶ Sed restat, u…", in: id., Relectiones Theologicae XII (1557), vol. 1). Making appeal to the decrees of the Council of Constance, Solórzano remembers that neither infidelity nor any kind of mortal sin annulate dominium, which, instituted by human reason and natural law, does not have its foundation in Faith and grace (Solórzano, De Indiarum iure II, cap. 10, § 57-60, pág. 373). In Soto's De iustitia et iure, where the issue is solved after a thorough distinction between kinds of law, we find the idea that dominium is not nullified by the fact that the proprietor or ruler is an infidel since divine positive law and its distinction between believers and non-believers generally does not invalidate human law (Soto's De iustitia et iure, lib. IV, q. 4, art. 1, p. 302. Cf. also his earlier Relectio de dominio (1995), §32, pp. 170-3). Rephrasing their ideas in contemporary words, we could say that, for the Salamanca masters, civil law and its institutions, such as property (proprietas) and political rule (iurisdictio), can and should be justified independently of any religious conviction.

War, slavery, jurisdiction

From this fundamental core other implications related to war, slavery or conversion, particularly imbued by the polemics on the asuntos de Indias, are deduced or aggregated in the writings of most of the Salamanca masters. Vitoria denied that infidelity in itself can serve as a legitimate ground for war against infidels (Vitoria, De Indis prior, paragr. "¶ Quarta conclu…", in: id., Relectiones Theologicae XII (1557), vol. 1), conquest and occupation of their territories, or even just for interference in their civil administration. After him and making appeal to almost the same sources, rebutting the same medieval contrary authorities -namely Enrico da Susa (Hostiensis) and Richard FitzRalph (Armachanus)- and employing very similar arguments, Salamanca jurists and theologians such as López (Partida II, Título XXIII, Ley II, Glosa Magna, Novena Conclusión, pág. 181), Acosta (De procuranda indorum salute, Libro II, Cap. II, Vol. I, págs. 260-261) and Azpilcueta (Relectio in cap. Novit de iudiciis, Notabile III, § 58-64, pp. 43-44) considered that, since a war declared exclusively on account of the infidelity was unjust (in the absence of a clear iniuria inflicted on Christians), it was also unjust to enslave infidels or to deprive them of their property without a supplementary legitimate casus belli.

Insofar as the Pagan peoples of the Americas perfectly exemplified the kind of infidels which could be blamed by (almost) nothing more than their mere infidelity as such -a kind of Kantian concept without percept in medieval theological speculation-, they appear time and again as leading protagonists of the different dubia on infidelitas and dominium. For Jews and Muslims living under the authority of Christian princes, their infidelitas and relationship with Christian subjects was a matter of internal policy. Instead of the war casuistic, the criminal legal frameworks regarding rebellion, suspicions on proselytizing and threatening the faith of Christian subjects and apostasy -for the case of Muslims and Jews who, forced to convert in order to be able to remain in Spain, were only nominally Christians- was applied by the Salamanca authors to justify enslavement and expropriation campaigns (cf. Báñez, De Iure et Iustitia Decisiones (1594), q. 1 art. 3 comment. paragr. "Nihilominus sit…"). It is also important to underline that the Inquisition did have some jurisdiction with regards to non-baptized living under the authority of Christian princes.²³23 As the manuals for inquisitors of this period recognize; cf.…
As the manuals for inquisitors of this period recognize; cf. Simancas, Diego de, Institutiones Catholicae (1552), Cap. XXIX, “De Mahumetanis”, Valladolid, Egidio de Colomies, f. 137v. North African Saracens and Turks were, on their own, unanimously considered as enemies (hostis) of Christianity. Therefore, even in the absence of a current and effective threat or iniuria, they could be fought, plundered and enslaved on account of their traditional hostility to Christians.²⁴24 Even the most cherished and vindicated theologian of the Sch…
Even the most cherished and vindicated theologian of the School of Salamanca, Bartolomé de Las Casas, shared this common position, appealing also to the permanent war against Saracens and Turks on behalf of the Christian princes' right to recover (ius recuperationis) all the territories which once had been under the jurisdiction of the Church. Cf. Las Casas, De unico vocationis modo, [Obras completas, Vol. II, Madrid, Alianza, 1990, pp. 575-576]. A general perspective on the Spanish sources is David Thomas and John Chesworth, Christian-Muslim Relations. A Bibliographical History. Volume 6 Western Europe (1500-1600), Leiden, Brill, 2015, pp. 41-294. Also Heretics lose the dominium over their goods and subjects on behalf of their infidelity, and were deprived of it after the mandatory judicial sanction (Castro, Alfonso de, De iusta haereticorum punitione, Libri III, Lyon, Sebastiano Bartolomeo Honorati, 1556 (ed. orig. 1547), Caps. VI-VII, pp. 280-304.

While there was agreement on the position that sola infidelitas does not make void the dominium of infidels over goods (dominium rerum suis), there was no unanimity regarding their jurisdictional rights (dominium iurisdictionis). The debates between the Salamanca jurists and theologians on this issue was very intense, and we find occasionally the same kind of harsh disagreement than in the discussions about the possible salvation of infidels living according to natural law. As previously stated, infidelity per se could not justify such a degradation of infidel rulers, but, on the other hand, if infidels' jurisdiction had really been considered unassailable, it would have been very difficult to justify, for example, the wide translatio imperii process taking place, de facto, between Native princes and Castilian kings since the end of the 15th century.

In general terms, it was considered that while Christians shall not permit that an infidel becomes ruler over Christians (which harbours the dangers of scandalum or periculum fidei), this does not invalidate the pre-existing authority of an infidel authority. Nevertheless, the tendency in this case was to elaborate more and more refined and casuistic arguments that, upholding the legitimacy of the dominion exercised by infidels in general terms, justified their dethronement or submission to a Christian superior ruler in some specific cases. The more the process of conversion to Christianity of the subjects of some infidel lord was on the track, the more fragile became the jurisdictional dominion exerted by him. Following Vitoria's De Indis, infidels' opposition to the preaching of the Christian faith or to the conversion of their subjects to Christianity (Vitoria's De Indis prior, art. 12, paragr. "¶ Quarta conclu…"), was almost unanimously admitted as a just cause for the dethronement of an infidel ruler. Later scholastics were much more precise and in many instances more cautious than Vitoria in the exposition of this ius praedicandi. For example, for Gregorio de Valencia, it is licit to foil, by force if necessary, attempts to prevent the preaching of the gospel; however, it is not allowed to force infidels to listen (Valencia, In II-II (1603), disp. 1, punct. 8, coll. 428-9). This and other important points remained unclear in the pioneer exposition of Vitoria, who despite judging as sinful such a refusal to listen, had not specified if some practical coercive means could be employed to overcome it (Vitoria's De Indis prior, art. 36).

While some authors of the School admitted only actions against predication that had in fact taken place, or iniuriae and actual persecutions against the already Christianized subjects as grounds justifying the annulment of rule (cf. Peña, Juan de la, De bello contra insulanos, q. I, art. 7, Madrid, CSIC, 1982, p. 154), a growing majority considered sufficient the potential threat to the Faith²⁵25 In De fide, Suárez refers to it as periculum moralis and Ave…
In De fide, Suárez refers to it as periculum moralis and Avendaño, quoting him and developing his conclusions in his Thesaurus Indicus (1668; vol. 1, tit. 1, cap. 1, paragr. "Quod quidem ex…"), spoke of a periculum subversionis to be avoided. that an infidel ruler over a people being Christianised represented. Solórzano and Acosta considered, for example, that under an infidel ruler, Christian vassals would be always at risk and that to avoid this kind of uncertainty the adoption of categorical preventive measures was justified.²⁶26 Cf. Solórzano, De Indiarum iure II, Cap. 11, § 55-60, pp. 40…
Cf. Solórzano, De Indiarum iure II, Cap. 11, § 55-60, pp. 402-405; Acosta, De procuranda indorum salute, Libro III, Cap. II, Vol. I, pp. 392-393. For authors such as Suárez and Avendaño, reflecting on an 17th century European, American and Asian context, in which many lords became Catholic by a non-genuine will, even conversion to the Faith was not enough for a former infidel prince to keep his dominium iurisdictionis. They considered the Church legitimized to overthrow all converted rulers whose character it deemed inclined them to any kind of periculum subversionis (Avendaño, Thesaurus Indicus, vol. 1 tit. 1 cap. 1 paragr. "Quibus addendum…").

Contrary to the dubious political implications resulting from the ius praedicationis, the Salamanca scholastics agreed on the fact that infidel rulers’ leniency regarding sins against natural law committed in their republics could not justify their dethronement. For Vitoria and Soto, the Pope and Christian rulers lacked the jurisdiction to punish infidels’ sins.²⁷27 Cf. Vitoria, De Indis prior, art. 40 ; Soto, De iustitia et …
Cf. Vitoria, De Indis prior, art. 40; Soto, De iustitia et iure, lib. V, q. 3, p. 445. Later authors such as Gregorio de Valencia and Fernando Vázquez de Menchaca considered even the argument as iniustum and incivile: similar violations were committed every day in the Christianized world, without being alleged as a cause of interference or even war between the Christian republics.²⁸28 Cf. Valencia, In II-II (1603), disp. 1, punct. 7, coll. 431-…
Cf. Valencia, In II-II (1603), disp. 1, punct. 7, coll. 431-6; Vázquez de Menchaca, Fernando, Controversiarum illustrium, Cap. XXIV, "De Bello contra Infideles", Frankfurt, 1668, p. 102.

Historiography has been particularly interested in these issues that can easily -and, sometimes, anachronistically- be put into relationship with contemporary debates about colonialism and international law.²⁹29 Among the most recent attempts to extrapolate the "lessons" …
Among the most recent attempts to extrapolate the "lessons" from early modern Salamanca to the contemporary global order: Beneyto, José María and Corti Varela, Justo (eds.), At the Origins of Modernity. Francisco de Vitoria and the Discovery of International Law, Heidelberg, Springer, 2017. Some of the contributions to this book engage in a harsh polemic against the critical school of international legal scholarship, Third World Approaches to International Law (TWAIL), whose members saw in the School of Salamanca the origins of a perverse regulatory global dynamic. See Anghie, Antony, “Francisco De Vitoria and the Colonial Origins of International Law”, in: Social & Legal Studies 5:3 (1996), 321-336. In Spain, a project of edition led by Prof. Luciano Pereña within the National Research Council (CSIC) focused exclusively on the edition and translation into Castilian of most of the Salamanca sources related to war against infidels under the misleading name Corpus Hispanorum de Pace (CHP), where the slight nuances differentiating each author can be appreciated. Apart from the sources above mentioned, writings of Salamanca theologians such as Las Casas' De Regia Potestate (1571), Roa Dávila's De Regnorum Iustitia (1591) and Veracruz's Relectio de dominio infidelium et iusto bello (1553-54), edited within this CHP project, deserve a careful reading.

Typology of infidels and debates on their conversion and baptism

The political and juridical debates on infidel rulers’ dominium iurisdictionis is closely connected in all the Salamanca masters with an extensive theological discussion about the legitimate and most convenient ways that Christians could and should employ in their attempt to convert infidels to the True Faith. On its own, these debates on infidels’ conversion presupposed the classical framework differentiating between several kind of infidels, slightly updated in the light of the experience gained by missionary theologians in Early Modern period.

In fact, the classical typologies constructed by Thomas Aquinas, Matías De Paz and Tommaso de Vio (Cajetan) appear to be fully consolidated in the 17th century, when not only learned theologians, but also jurists³⁰30 E.g. Solórzano, De Indiarum iure L. II, Cap. 10-11, § 55-60,…
E.g. Solórzano, De Indiarum iure L. II, Cap. 10-11, § 55-60, pp. 402-405, where infidelitas, as a title justifying per se the war and subjugation of Native American Pagans is discussed. and authors of manuals for priests and confessors³¹31 Cf. Peña Montenegro, Itinerario para párrocos de indios (177…
Cf. Peña Montenegro, Itinerario para párrocos de indios (1771), Libro II, Trat. 8, Sección 6, Vol. I, págs. 553-555. Peña follows Las Casas' De unico vocationis modo, which refers, in turn, to Cajetan's commentary on the II-IIae, q. 66, art. 8. wrote about American and Asian infidels taking these classifications for granted. The turn from 16th to 17th century experienced not only a mere repetition of old doctrines, but also new substantial contributions to the differentiation process of the new infidel peoples developed in parallel to the global Christian expansion. In the introductory remarks to his influential De procuranda indorum salute, José de Acosta added new criteria -neither properly theological nor juridical, but missiological- aimed to help the Churchmen teaching the Gospel worldwide in the selection of the means that they could put into practice to convert the infidels residing in their sphere of action. In order to do so, Acosta considered it very important to take into account the state of civilization that a certain infidel population had reached until the beginning of its Christianization process, and he classified all Asian, American and some Oceania infidels (notable from the Solomon Islands) into three big groups, defined by their degree of use of recta ratio (Acosta, De procuranda indorum salute, “Prooemium”) Even if in De procuranda, Acosta makes use in turn of the non-synonymous terms infidelis and barbarus -something that can be seen in many other contemporary sources-, both concepts are merged in his contribution, where every non-Christian is, in fact, referred to as barbarus, a term whose classical meaning (Aristotle) could hardly be applied to Chinese, Japanese and other highly civilized infidel peoples.

Also in Francisco Suárez's Tractatus de fide theologica, whose arrangement of the questions regarding infidelity (De fide, disp. 16-18, ed. Berton, pp. 405-60) still owes a great deal to Thomas Aquinas's STh, there is an important contribution to the traditional classificatory scheme. In disputation 16, Suárez spoke of a new kind of pure infidelity, that may be called 'philosophical', such as that of one who wants to be neither pagan, nor Jew, nor Christian, but who nonetheless worships one God whom his reason recognizes (De fide, disp. disp. 16, p. 415). In Suárez’s words we find an echo of the kind of the barely budding Socinian rationalist infidelity which became popular during the Enlightenment.

The theoretical debates on the definition of infidelitas and the progressive differentiation between infidels discussed above are closely connected to the way in which Salamanca scholastics understood conversio and baptismus. As Aquinas had evaluated the legitimacy of forced conversions and of baptism of infidels’ children without parental consent in his approach to infidelity in his Summa³²32 STh II-II, q. 10, art. 8 (Utrum sint cogendi ad fidem), art.…
STh II-II, q. 10, art. 8 (Utrum sint cogendi ad fidem), art. 12 (Utrum pueri infidelium sint invitis parentibus baptizandi) [Editio Leonina, 1895, pp. 88-90, 93-96] and these were major practical issues which were debated once and again in the missionary golden age of Early Modern period, Salamanca scholastics wrote profusely about both issues.

The important role that the complex conceptual framework on infidelity developed by the School of Salamanca had in orientating many practical resolutions has to be properly underlined. While moral theologians and missionaries (mostly Franciscans) working under a poorly developed and unclear conceptual paradigm which, in a very simplistic way, considered infidelitas as the state in which every non-baptized was, launched campaigns in which the sacrament of baptism was massively administered to non- or only superficially instructed infidels,³³33 For the Pagan populations of Mexico, see Cline, Sarah, “The …
For the Pagan populations of Mexico, see Cline, Sarah, “The Spiritual Conquest Reexamined: Baptism and Christian Marriage in Early Sixteenth-Century Mexico”, in: Schwaller, John Frederick (ed.), The Church in Colonial Latin America, Wilmington, Scholarly Resources, 2000, pp. 73-102. Salamanca scholars and Church practitioners missionizing in accordance with their teaching unanimously condemned such practices. For Vitoria, Soto and the other six colleagues of the Faculty of Theology which signed a critical Parecer sobre el bautismo de los indios sent to the Spanish King in 1541 , baptism was not enough to make a "true Christian" out of an infidel.³⁴34 Vitoria, Soto et al., “Parecer sobre el bautismo de los indi…
Vitoria, Soto et al., “Parecer sobre el bautismo de los indios”, in: Vitoria, Francisco de, Relectio de Indis o Libertad de los Indios (ed. by Luciano Pereña, José Manuel Pérez Prendes. Madrid, CSIC, 1967), p. 157-164, cit. p. 164. Every adult infidel to be baptized needed a proper previous instruction on the Faith (Vitoria, Summa Sacramentorum (1561), pars 2 q. 30 paragr. "¶ QVÆRITVR, quo…") that he or she would assume through baptism, as the degree of grace itself to be conferred by the sacrament depended on the disposition of the infidel to receive it and its voluntary adherence, inexistent in the case of non-catechized adult infidels (Vitoria, Summa Sacramentorum (1561), pars 2 q. 18 paragr. "¶ QVÆritur, an…"). While the administration of baptism should be considered the indelible mark, which implied the entry in the Church of a child being born in a Christian family of a Christian republic, making him or her the depositary of the corresponding rights and obligations prescribed in the normative order of the institution,³⁵35 Meyer, Christoph, “Nichtchristen in der Geschichte des kanon…
Meyer, Christoph, “Nichtchristen in der Geschichte des kanonischen Rechts. Beobachtungen zu Entwicklung und Problemen der Forschung”, in Rg 26 (2018), p. 144, DOI:10.12946/rg26/139-160. the same could not be said without reserve not only for adult infidels to be baptized, but also with regards to those many baptized in the overseas dominions of the Catholic monarchies, which once baptized, were left to their own devices. In the first case, the growing of the child in the Christian faith was socially and institutionally assured. Oppositely, the adult infidel having been educated into another religious culture and tradition or the baptized child abandoned to his or her fate risked to incur into serious infringements of divine and natural law -implying mortal sin and eternal damnation- if not properly and continuously instructed in the Christian faith. The risk of apostasy and returning into traditional religious beliefs and rites was presumed to be enormous. For these adult infidels, the transition from infidelitas to Christianity was understood by Salamanca scholastics as a process characterized by a progressive overcoming of ignorance and a parallel eradication of errors regarding True Faith and moral conduct. While in the case of Muslims and Jews, rooted errors were the challenges to which the catechization process pointed, Pagan Americans were conceived as well-disposed peoples who, affected by the invincible ignorance we already mentioned, were thought to need a long-term indoctrination process, which, for the most cases, should be continued during their whole life as neophyti. Otherwise, the baptism once received did not make them different from non-baptized infidels, sharing all the same kind of ignorantia invincibilis regarding Faith and most precepts of natural law.³⁶36 Peña Montenegro, Itinerario para párrocos de indios (1771), …
Peña Montenegro, Itinerario para párrocos de indios (1771), Libro II, Trat. VIII, Secc. IX, p. 219

Coexistence and communication between Christian and infidels

The last of the great topics related to infidelity that remains to be addressed is that of the regulation of coexistence or "communication" between Christians and infidels: The actual, potential, or presumed threats that infidels represented vis-à-vis the Christian faith marked the limits of an interreligious living together made possible by the same acceptance of a religious diversity that was understood at the same time as a persistent and irremediable evil -inasmuch as the forced conversion of infidels was unanimously rejected, since to believe depends on the will (STh II-II, q. 10, art. 9). Only Christian heretics and apostates could be, in fact, coerced to abjure their errors and deviations from True Faith. In these and other general points, Salamanca scholastics repeated without further additions a classical convivencia paradigm according to which public force may, in fact, only be used to prevent all other kinds of infidels (Jews and Muslims) from persecuting Christians or attacking the Christian faith by means of blasphemy and evil persuasion.

The permissibility of interaction between Christian and infidels depended on the various aspects and conditions of any given concrete case. In general terms, where neither scandalum nor periculum fidei was to be expected, interaction seemed licit. This also applied to the permissibility of public debate about religious matters with infidels, an issue in which Thomas Aquinas's prudential criterion (STh II-II, q. 10, art. 7) was unanimously considered as valid: where the negative outcome would be the defection of a Christian interlocutor or audience and the positive outcome would be the persuasion and conversion of a former infidel, the permissibility depended on the actual balance of these eventualities.

With regards to interaction with the classical infidels, Jews and Muslims, Salamanca scholastics repeated the equally classical long list of prohibitions contained in the main sources of canon law: to give but one example, Juan de Azor takes into account in his Institutiones morales (1613) the prohibitions for Christians of living, eating and taking bath together with Jews, making use of Jewish doctors and medicines prescribed by them, allowing their children to be nourished by Jews and borrowing them servants. It was not allowed for Jews to have Christian servants and hold public offices ( Azor, Institutiones morales, Pars I, L. VIII, Cap. XXII, p. 553). Food was a particular field of confessional battle, and Christian responded to infidels’ prohibitions such as the one of eating pork, prohibiting the eating of unleavened bread (ibid.). Of course, visiting synagogues, mosques and other infidel temples and the participation in infidel feasts were forbidden to a Christian (Ibid., pp. 553-554). The traditional regulation tried, in fact, to reduce the interaction of Christians with other religious communities to the minimum needed for the common good of the republic in which both Christians and infidels lived. In this sense, while interreligious commerce was allowed in general terms, any other kind of social intercourse made with ludic purposes fell under a severe prohibition. In general terms, we can say that Salamanca jurists maintained a rigorous legal framework which obliged, for example, to remove the whole cover of a Church's walls if an infidel was improperly buried inside the temple (Azpilcueta, Manual de Confessores y Penitentes, cap. 27, num. 253, paragr. "¶ El segundo ca…").

As in many other fields, the most original contributions made by Salamanca scholasticism had to see with the new kind of Pagans recently discovered overseas, to which the obstinata perfidia (Azor, Institutiones morales, Pars I, L. VIII, Cap. XXII, p. 553) from which Azor had spoken in trying to describe the attitude of Jews in their presumably problematic convivencia with Christians, could hardly be attributed. Contrary to the spirit behind a traditional regulation still repeated in moral-theological compendia such as the one of Azor, aimed to protect the faith of Christians from any possible infidel contamination, the normative framework conceived by the Spanish monarchy -strongly influenced by the Salamanca reflections and lobbying- to regulate the convivencia between Iberian Christians and American infidels being converted to Christianity, tried to protect the incipient faith of those infidels, presumed as innocent and well-intentioned, from the pernicious examples of life provided by the bad Christians surrounding them, conquerors, encomenderos and other laymen described by many missionaries in highly critical terms.³⁷37 Acosta, De procuranda indorum salute, Libro III, Cap. V, p. …
Acosta, De procuranda indorum salute, Libro III, Cap. V, p. 293. From the beginning of the conquests, many voices were therefore raised asking for the concentration and isolation of Natives infidels in pueblos de indios, reducciones or hospitales to which only clergymen could have access. Such a normative framework was insistently demanded by Las Casas (Bartolomé de Las Casas, Entre los remedios […] el octavo, Sevilla, Cromberger, p. 299), firstly put into practice by the Salamanca jurist Vasco de Quiroga³⁸38 See Verástique, Bernardino, Michoacán and Eden. Vasco de Qui…
See Verástique, Bernardino, Michoacán and Eden. Vasco de Quiroga and the Evangelization of Western Mexico, Austin, University of Texas Press, 2000. and lasted until the dismantlement of the 18th century Jesuit missions. Nevertheless, we cannot really speak about a common Salamanca point of view on this issue, given that many authors tried to reconcile the search for the spiritual good of the Indians with the material ends naturally ambitioned by the Spanish settlers: authors such as Acosta supported the encomienda system, and considered, that despite some abuses, the frequent coexistence between Christian laymen and Natives was the only possible way for the latter to abandon their bestial habits and get a Christian instruction (Acosta, De procuranda indorum salute, Libro III, Cap. XIX, pp. 355-356).

Insofar as the American Pagans would not compromise the faith of their Christians neighbours, they were allowed to "communicate" and live with them. Nevertheless, prohibitions created for Jews and Muslims, such as the one of holding public offices were also applied to them. As Azpilcueta recalls in his Manual de Confessores, other functions that provided honour and social recognition, such as the one of being baptismal godparent, could only be performed by Christians (although infidels could baptize in case of need).³⁹39 Azpilcueta, Manual de Confessores y Penitentes, cap. 22 num.…
Azpilcueta, Manual de Confessores y Penitentes, cap. 22 num. 6.

In many civil and religious issues regarding such different topics as marriage, divorce, contracts, commerce, tributes or clothing, infidelitas had to be taken into account by jurisdiction holders in foro interno et externo. Infidelitas did not preclude the celebration of a contract or the completion of a commercial transaction, but it was always a conditioning factor and, in some specific cases, it could even obstruct or impede the action.

Marriage

For example, a marriage contracted between a Christian and a non-baptized -even if catechumen- was considered null and void.⁴⁰40 Cf. Azpilcueta, Manual de Confessores y Penitentes, cap. 22 …
Cf. Azpilcueta, Manual de Confessores y Penitentes, cap. 22 paragr. "¶ Lo tercero, q…". This was contrary to the marriage contracted with a heretic, valid even if sinful and indissoluble even after one of the spouses became heretic. Cf. Azpilcueta, Manual de Confessores y Penitentes, cap. 22 paragr. "¶ Lo tercero, q…". Regarding marriages between infidels, those not contravening natural law (i.e. marriages between parents and their own children) were generally considered to be legitimate contracts, but these unions did not have the same status as a Christian marriage, the only one considered to be ratum and indissoluble (once consummated). Contrary to this, the marriage contracted between infidels became particularly fragilized and problematic from the moment in which one of the spouses converted to Christianity. They were not dissolved ipso facto, but the converted spouse could abandon the infidel one after its conversion and even divorce and marry a Christian if the infidel spouse had put his/her Faith in danger (Azpilcueta, Manual de Confessores y Penitentes, cap. 22 paragr. "¶ Lo segundo, q…"). In order for their marriages to have the same degree of juridical strength and for the spouses to enjoy the same rights as Christian spouses, husband and wife -or only the infidel spouse in the case of interreligious couples- must be baptized. Within the School of Salamanca it was a matter of debate if, after the baptism of the spouse/s, the marriage had to be celebrated again according to the Christian rite (in facie ecclesiae). Considering the practical impossibility of marrying each overseas infidel in strict compliance with all canonical formalities, pragmatic criteria began to emerge throughout the 16th century and the administration of baptism tended to be considered sufficient to make fully sacramental a marriage contracted in tempore infidelitatis.⁴¹41 Cf. Alonso de la Vera Cruz, Speculum coniugiorum (1562), Art…
Cf. Alonso de la Vera Cruz, Speculum coniugiorum (1562), Art. XXXVI, pp. 452-453.

American Pagans were, in fact, and once again, a touchstone for traditional doctrines regarding marriage. In a treatise consecrated to examine if infidels, and specially the peoples of the New World celebrated true marriages despite being or having been infidels,⁴²42 Dubia raised by Vera Cruz in Articles 1 and 2 of the Second …
Dubia raised by Vera Cruz in Articles 1 and 2 of the Second Book of the Speculum: Articul. Primus. Utrum inter infideles sit verum matrimonium. Art. 2. Utrum inter huius novi orbis incolas fuerit etiam verum matrimonium.. Alonso de la Vera Cruz gave not only an affirmative answer to the question. Considering that, as something to which nature inclined every human being, marriage -such as the possession and exercise of virtues that we mentioned- was an essential part of human nature of both Christian and infidels,⁴³43 In the argument about human nature, Vera Cruz relied on the …
In the argument about human nature, Vera Cruz relied on the authority of Aristotle, who in his Ethics had considered the human being, to be more a conjugal animal than a political one; cf. Vera Cruz, Speculum coniugiorum, L. II, art. I, p. 265. he even defended that the marriages contracted by infidels in strict compliance with natural law could be considered as having a certain sacramental character -as signs of something sacred- and conferring a certain degree of grace (Ibid., L. II, Art. XXXV, p. 451). This position opened a front of controversy with rigorous presenters of the traditional canonical framework such as Azpilcueta (Manual de Confessores y Penitentes, cap. 22 paragr. "PResuponemos lo…"), Soto or Manuel Rodríguez (El Lusitano) –usually advocated in 17th writings on sacraments such as the popular Castilian Suma by Pedro de Ledesma⁴⁴44 Pedro de Ledesma, Primera parte de la suma en la qual se cif…
Pedro de Ledesma, Primera parte de la suma en la qual se cifra, y suma todo lo que toca y pertenece a los sacramentos (1617), “Del sacramento del matrimonio”, Cap. XXIV, p. 522.-, especially because, in his attempt to adapt with a certain flexibility classical legal prescriptions to the American social realities, Vera Cruz arrived to consider consanguineous marriages contracted between infidel brothers and sisters as according to natural law and not to be dissolved if they converted to Christianity. Oppositely, Soto (whose authority -in Soto, De iustitia et iure, L. II, q. 3, arts. 7 y 8- was, precisely, challenged by Vera Cruz in his Speculum coniugiorum, L. II, Art. XXII, pp. 382-383) and later masters of the School never admit as valid and indissoluble the marriage contracted by infidels within the first degree of transversal consanguinity.⁴⁵45 Cf. e.g. Pedro de Ledesma, Primera parte de la suma, Cap. XI…
Cf. e.g. Pedro de Ledesma, Primera parte de la suma, Cap. XIV, p. 484.

Similar in a certain way to Vitoria’s and Soto’s speculations about the possibility of salvation for infidels following the dictates of natural law, Vera Cruz's reflections can be seen as an example of the many innovative nuances to which the need of accommodating traditional normative frameworks to the new challenges faced by the Iberian missionaries drove the intellectuals in charge of elaborating general theological and juridical guidelines. Though well argued, this kind of innovative positions led to a polarisation of opinions, being very problematic to speak properly of sacraments and salvation outside the Church.

Fiscal issues

Many fiscal issues regarding the way in which infidels living under a Christian prince should be taxed were also re-evaluated in the light of a new scenario in which, suddenly, some Christian monarchs had more infidel than Christian vassals. While some Salamanca authors, driven by their missionary zeal, pronounced themselves in favour of burdening with the highest tax rates possible those perfidi and obstinati infidels refusing to convert to Christianity,⁴⁶⁴⁶Cf. Acosta, De procuranda indorum salute, L. III, p. 329. the masters of the first generation of the School criticised this unequal and discriminatory fiscal policy as being as an illegitimate way to increase conversions. Vitoria, Soto or Vera Cruz also had the political ideas of Aristotle, Thomas Aquinas and Giles of Rome in mind and defended that, under a Christian legitimate ruler, the burden of taxes payed by all vassals -Christians and infidels- should be always less than under former infidel tyrannical authorities, so that infidel subjects could appreciate the Christian virtue of magnanimity and, driven by positive voluntary motivations, decide to convert.⁴⁷47 Cf. Vera Cruz, Relectio de dominio infidelium et iusto bello…
Cf. Vera Cruz, Relectio de dominio infidelium et iusto bello, Dubium XI, 821-822.

A similar research of fair general criteria of conduct against an arbitrariness usually masked under the guise of religious zeal was also pursued for the case of Christian living under the authority of an infidel prince or undertaking transactions which implied the payment of a certain alcavala or tribute to them. As Pedro de Ledesma stated in a 17th century Summa synthetizing Vitoria’s, Soto’s and later Salamanca masters’ doctrines, infidelitas could never be considered as a reason to disobey or to refuse to pay taxes. Infidel rulers did not inflict any iniuria demanding tributes from their Christian subjects. Even in the case of infidel authorities occupying former Christian and Imperial lands, resistance to taxation was forbidden, as any individual initiative aimed to recovery those usurped goods should be let to the initiative of public authorities such as the Pope and Christian princes.⁴⁸48 Pedro de Ledesma, Segunda parte de la suma, en la cual se ci…
Pedro de Ledesma, Segunda parte de la suma, en la cual se cifra y suma toda la moral y casos de conciencia que no pertenecen a los sacramentos (1617), Tratado séptimo, p. 193.

Commerce

One of the most regulated fields in the problematic convivencia of Christians and infidels was commerce. In general terms, it was allowed to maintain commercial relationships with infidel individuals and republics. According to the Salamanca masters, the respect of the good faith principle, indispensable for the stability of contracts, promises and social relationships, was also mandatory in the case of trade with infidels and its violation obliged Christian to the restitution to the infidel of the goods usurped.⁴⁹49 Pedro de Ledesma, Segunda parte de la suma, Tratado séptimo,…
Pedro de Ledesma, Segunda parte de la suma, Tratado séptimo, p. 193. The classical sources of Canon Law had already prohibited Christians to sell infidel goods potentially harmful for Christians themselves, such as weapons and raw materials suitable for their manufacture, or products to be used in non-Christian religious rites.⁵⁰50 Pedro de Ledesma, Segunda parte de la suma, Tratado primero,…
Pedro de Ledesma, Segunda parte de la suma, Tratado primero, p. 23. Those prohibitions were repeated in the normative literature written by the Salamanca masters, who recommended the seizure and confiscation of this kind of goods.⁵¹⁵¹E.g. Vitoria, De Indis prior, paragr. "¶ Quinta propos…". The Castilian monarchy could also rely on a long tradition of norms regulating commerce and wars with infidels. Especially influential until 18th century were Alfonso X’s Partidas. Appealing to some of their provisions, the jurist Hevia de Bolaños considered even that Christian merchants selling arms to the enemies of the Faith -and soldiers and pilots at their service- could be enslaved.⁵²52 Hevia de Bolaños, Curia Philippica (1603), Libro I, Cap. XII…
Hevia de Bolaños, Curia Philippica (1603), Libro I, Cap. XII. On this kind of issues, Azpilcueta was, without doubt, the author who mostly contributed to adapt that traditional framework to a new context marked by the settling of commercial relationship with the 'new' Pagan peoples of the Western Indies and the growing military and economic power of Turks. In his Manual de Confessores, he incorporated recent legal provisions such as Julius III’s bull In Coena Domini (1550), extending the penalty of excommunication to any merchant selling arms to infidel peoples or princes in actual or virtual war with Christians, including a new kind of hostile Pagans which after six decades of predication of the Christian faith in America, still resisted to it.⁵³⁵³Manual de Confessores y Penitentes, cap. 27 num. 62. The Doctor Navarrus dedicated also a long repetitio to clarify the many specific issues which had arisen in the new context of a commerce with infidels which had become global, linking for the first time in history Europe, Africa, America and Asia.⁵⁴54 Azpilcueta, Relectio cap. Ita quorundam de Iudaeis in qua de…
Azpilcueta, Relectio cap. Ita quorundam de Iudaeis in qua de rebus ad Sarracenos deferri prohibitis et censuris ob id latis non segniter disputatur (1550), Coimbra, Ioannes Barrerius & Ioannes Aluarus. Azpilcueta redirected the readers of his Manual to this more specific repetitio for further precisions.

Further perspectives. Conclusion