Scholars, and the general public as well, have shown continuing interest in the intensive missionary efforts of the seventeenth-century Jesuits in China. 1 Few in the West, however, are familiar with the remarkable efforts undertaken nearly contemporaneously by Alexandre de Rhodes among the people of China's southern neighbor, Vietnam. De Rhodes, a Jesuit from Avignon, France, understood well the power of ideas; and, as an individual who was intellectually ahead of his times, he skillfully used an array of new ideas in persuading the Vietnamese people to accept the religious message that he brought them.

It would be difficult to do justice in a short study to all of de Rhodes's amazing accomplishments. One would need to discuss his contributions in several specific areas: to the Vietnamese people, particularly in respect to religion and linguistics; to the Roman Catholic Church, in his successful broadening of its mission effort in Asia; and to Europeans, for whom he provided, through his engaging narratives of travel, not only a wealth of new knowledge about Southeast Asia, but also his views on the values he saw in Asian culture: the prominence in his travel narratives of the theme of cosmopolitanism--the willingness to acknowledge the values of others and even to consider the adaptation to one's own culture of foreign cultural elements, one of the key concepts in the coming century of Enlightenment--provides a striking illustration of the advanced nature of de Rhodes's ideas and his absorption with them.

But to understand and appreciate de Rhodes, it may be more useful to focus on one particular aspect of his work than to engage in a brief analysis of each of his many successes. By examining carefully an individual theme from his own writings, one can gain meaningful insights into both his intellectual outlook and his method of influencing the Vietnamese: de Rhodes's insistent presentation of new European scientific knowledge as well as contemporary European applications of the concept of reason represents one of the most dynamic of these themes. While the use of these ideas constitutes only a small part of de Rhodes's missionary approach, which was in the main theological, 2 it is significant in demonstrating his ties with the intellectual era in which he lived and the succeeding one as well.

The use of science, mathematics, and reason was indeed the method that had already proven successful for the Jesuit Matteo Ricci, one of the best known of the early exponents of Christianity in China. As Ricci explained in his journal: Whoever may think that ethics, physics and mathematics are not important in the work of the Church, is unacquainted with the taste of the Chinese, who are slow to take a salutary spiritual potion, unless it be seasoned with an intellectual flavoring. 3 Alexandre de Rhodes, beginning his missionary work in Vietnam in late 1624 or early 1625, about fourteen years after Ricci's death, took to heart his predecessor's gustatory dictum, adapting to the taste of his own listeners in Vietnam the most advanced European thinking of his day.

That de Rhodes is less well known today than he should be is a result, in part at least, of the inaccessibility of the books he wrote about Vietnam, of which no less than eight were published in France and Italy at the midpoint of the seventeenth century. 4 Those specialists who do know of de Rhodes's work are enthusiastic in their praise of his achievements. The scholar and historian of the Jesuits, William V. Bangert, calls de Rhodes one of the most effective Jesuit missionaries of all time. 5 And the French scholar Claude Larre and his Vietnamese colleague Pham Dinh Khiem, who together edited the 1961 Vietnamese republication of de Rhodes's Catechism, state that the Jesuit's brilliant mission work was in no way less outstanding than that of Matteo Ricci. 6

De Rhodes was born in 1593, 7 in the papal territory of Avignon in France, to which his ancestors, converted Jews, had migrated from Spain. After completion of his seminary training at the Jesuit Novitiate of Sant'Andrea al Quirinale in Rome, and further study of theology in the same city, de Rhodes, to his great satisfaction, received in 1618 an appointment to the Roman Catholic mission fields of Asia. He had begun to hope for a position in Japan, as he states at the outset of Divers voyages, at the very time the persecution began there, 8 and had made continual requests for the appointment. He arrived in Macao in May of 1623, accompanied by a Portuguese Jesuit, António Cardim, after a voyage which, including prolonged stays in Goa, the neighboring island of Salsette, and Malacca, had lasted for four years. Here in Macao, the headquarters for Jesuit missionary operations for the Japanese Province, which included Cochinchina and Tonkin, de Rhodes was to remain for another year and a half, preparing for his ultimate destination. But because Japan had by now been closed to Christian missionaries, de Rhodes in 1624 was appointed instead to the relatively new mission in Cochinchina.

At this time Cochinchina, together with Tonkin directly to its north, now the northern part of Vietnam, comprised an independent state, nominally under the rule of the Le Dynasty, with each region governed by its own viceroy. It was, in fact, these viceroys who held authority, the Le rulers having little real power. By the time of de Rhodes's arrival in the winter of with six other missionaries, the two regions, Cochinchina and Tonkin, were approaching a state of open warfare with each other.

While Christianity had been introduced into Tonkin and Cochinchina by European missionaries of various orders during the sixteenth century, the Jesuit mission in Cochinchina had begun less than a decade before de Rhodes's arrival. Fathers Francesco Buzomi and Diego Carvalho, and Brother António Dias, who had begun the Jesuit effort in 1615, had been joined by other priests in the succeeding years.

After eighteen months of missionary work in Cochinchina, during which time de Rhodes learned the Cochinchinese-Tonkinese or Vietnamese language and familiarized himself with the religions, customs, and government of the country, he was recalled by his superiors to Macao, in preparation for a move in 1627 to Tonkin. Because of his expertise in Vietnamese, he was selected, along with Pêro Marques, to staff a new mission there.

De Rhodes's excellent knowledge of the language of the Cochinchinese and Tonkinese would make it possible for him to undertake the project that was one of his greatest contributions to the people of these two areas: this was the development of a system for transcribing into Latin letters the Vietnamese language, which at that time used combinations of characters derived from Chinese characters to denote both the sound and meaning of a word. Several other missionaries, among them Gaspar d'Amaral and António de Barbosa, also experimented with this type of transcription, which made it possible for the missionaries to record Vietnamese words for their own use, in writing sermons, for example, in a form that was more workable for them. The romanized script also allowed the missionaries to produce religious materials for the new converts in a form that they were able to learn to read without great difficulty. De Rhodes made use of the work of his colleagues, but it is he who is given the credit for perfecting this romanization system, the fundamentals of which remain today. 9 It was also de Rhodes who would eventually publish the first book in this new transcribed form of Vietnamese, his Cathechismus, or Catechism in Eight Days. Because of his accomplishment in transcribing the language, which influenced the cultural development of Cochinchina and Tonkin in various significant ways, making it possible, for example, for the Vietnamese to interact more easily with European countries, using the Latin alphabet, 10 de Rhodes is even now remembered and highly esteemed in Vietnam.

De Rhodes continued his missionary work in Tonkin for two years in spite of developing opposition on the part of the viceroy. Although eventually exiled in 1629, he remained in the kingdom for another year, until the spring of 1630, when he returned to Macao. Here he was to spend a period of ten years, serving as chaplain for the new Chinese Christians, teaching theology at the Jesuit college, and working at times in the mainland province of Canton as well. His forced stay in Macao came about not as the result of the hostility of the authorities in Tonkin and Cochinchina, but because of the unwillingness of de Rhodes's superior to send him to the area. 11

With the appointment of a new superior in Macao, de Rhodes was able at last in 1640 to return to Cochinchina, this time as superior of the mission there. He then began a period of five fruitful but also dangerous years, during which he was to be frequently exiled by the authorities and forced either to return temporarily to Macao, or as he much preferred, to move about secretly within the Cochinchinese provinces. He was to witness during this period the decapitation of his catechist André, the first Christian martyr in Cochinchina. Finally in 1645, after he himself had been condemned to death, then released and exiled by the viceroy, de Rhodes left Cochinchina for the last time. From Macao he returned to Europe, arriving in 1649; there he pressed successfully for changes in the organization of the Cochinchinese and Tonkinese missions. In addition, he published his numerous books concerning Cochinchina and Tonkin. De Rhodes was appointed in 1655 to Isfahan, Persia, where he died in 1660.

In his best-known and most widely translated travel narrative, Divers voyages, de Rhodes presents a colorful vignette illustrating his method of beginning missionary work by gaining the attention of those in power. In March of 1627, after his initial three years of work in Cochinchina, the Jesuit was newly located in the Kingdom of Tonkin. Soon after his arrival, he presented to the viceroy, Trinh Trang, two European gifts, a clock and an hourglass. As de Rhodes demonstrated the self-chiming clock, he explained that it would strike again when the sand had completely passed through the hourglass. Near the end of the hour the viceroy, his eye on the sand, was becoming highly skeptical. 'Here it is run out,' he said, 'and your clock isn't striking.' When at this moment the clock struck. Trinh Trang was amazed and delighted, and immediately invited de Rhodes to stay with him for two years and to see him often. 12

In this story de Rhodes not only presents a close-up of a curious and clearly impressed ruler, but discloses at the same time a great deal about himself, the intellectual preoccupations of seventeenth-century Europe, and the missionary methods of his order. De Rhodes's century was, of course, undergoing a revolution in terms of ideas: medieval scholasticism, with its emphasis on religious dogma, was in the process of giving way to other concerns: the certainties of new mathematical concepts, the investigation of scientific principles, the observation of nature, and the new methods of Humanism for examining and explaining individuals and their world. The close reasoning that accompanied scholasticism carried over into the new areas of interest, and reason itself came to be elevated into a principle that could help resolve the ambiguities of mankind's surroundings.

The Society of Jesus was attentive to all of these intellectual developments and was well aware as the century progressed that the old scholasticism was losing ground. Although various eminent Jesuit theologians had defended scholastic learning and had contributed to it a new vitality in the latter part of the sixteenth century, 13 the Society was careful by the beginning of the seventeenth century neither wholly to embrace nor, on the other hand, to abandon the traditional concepts of scholastic philosophy. 14 Jesuit educators made deliberate efforts to remain in step with changing intellectual currents during this period, the years when de Rhodes was receiving his education and beginning his work. The Jesuit school curricula included not only classical languages--a mark of Humanistic learning--but also mathematics and science, by then receiving considerable stress in the intellectual world. 15

Long before this, however, specialization in the areas of mathematics and science had become a particular necessity for the Jesuit missionaries working in East Asia. Intent on presenting their message in terms the audience would understand and appreciate, and aware, since the pioneering days of Francis Xavier in Japan, of the attraction that mathematics and science held for the ruling circles and the literati in East Asia, the Jesuits took these intellectual concerns very seriously. As early as 1552 Xavier had written to King John III of Portugal advising him that it was necessary to send persons who were well educated so that they could answer the many questions that would be put to them by the populace. 16 The dual concept of demonstrating European scientific achievements and making a favorable impression on the elite of a nation later received concrete formulation in the principles set down by Alessandro Valignano in a plan he drew up for Jesuits being sent to China. Valignano urged the missionaries to make use of European science as a way of introducing their religious concepts to the people. In a separate point Valignano stressed that winning over the educated, who were the people responsible for government, would hasten the conversion of their nation. 17 Later Jesuits in China took these admonitions so much to heart that their enemies would come to refer to them acrimoniously as the mathematicians. 18 De Rhodes himself had prepared years before for these important tasks. Not only had he studied mathematics during his novitiate in Rome, but for the six months prior to his departure for Asia, he tells us, the study of mathematics had been his principal occupation. 19

De Rhodes's tactic of introducing European science and mechanical inventions in the form of the chiming clock in Tonkin met with initial success, gaining temporarily the good will of the viceroy. When Trinh Trang came under pressure, however, to resist the missionaries' influence, he began to distance de Rhodes from the court. The Jesuit then tried another approach, attempting to regain the ruler's confidence through his knowledge of astronomy. Foreseeing a lunar eclipse, de Rhodes and his colleagues developed a chart and a description of the event, several days before its occurrence. Since, at this time, they were no longer freely admitted to the royal palace, the missionaries, de Rhodes notes, found a way to get this chart that we had published to fall into the hands of the king. Trinh Trang, de Rhodes continues, praised our science highly; the ruler tried to restore the missionaries' reputation against the attacks of their adversaries. 20 While in the end, de Rhodes was forbidden to preach, and was exiled by the viceroy, he had succeeded in gaining the interest of those in power.

De Rhodes followed his astronomical tour de force for the viceroy with a similarly impressive demonstration of his knowledge for the governor of the province of Ghean (Nghean), where after being exiled by the viceroy, he spent some time. Here he had the opportunity to predict another eclipse, this time, of the sun. The governor's reaction was everything de Rhodes could hope for. Not only did he defend the missionaries against their detractors, but he encouraged the acceptance of the other message that the foreigners had brought. If these people, the governor stated, know how to predict with so much assurance and accuracy the secrets of heaven and the stars--which are unknown to us and surpass our capacities, shouldn't we believe that they are correct about the knowledge of the Law of the Lord of Heaven and of the earth, and of the truths that they preach to us . . . ? 21 De Rhodes's effort to associate both scientific and spiritual truth about le ciel, heaven, a methodology he was to employ on many occasions, again, at least temporarily, bore fruit.

In time, the rulers in Tonkin began to fear de Rhodes's influence and turned increasingly hostile to him. De Rhodes, however, continued with his appeals to the educated public, relying as he had with the rulers on a scientific approach. Seeing his success in the matter of the eclipse, the Jesuit made more formal linkages between mathematics, astronomy, and his explanation of Christian doctrine. Toward the end of his Cathechismus, the manual he prepared in Vietnamese for his Cochinchinese and Tonkinese catechists and followers, de Rhodes, for example, presents a historical account of the crucifixion of Christ. In describing the darkness that followed the crucifixion, he devotes a relatively long passage in proportion to the rest of the account to the scientific argument that this darkness could not have been the result of a natural solar eclipse because of the position of the celestial bodies at the time of year when the crucifixion took place. 22

De Rhodes's stress on the principles of mathematics and science came not only from his desire to gain the attention and confidence of the ruling circles and the literati but also from his own personal immersion in the new spirit of science that prevailed in Europe in his day. De Rhodes journeyed in the analytical spirit of his century. One sees in his manner a hint of the methodology of Thomas Hobbes, his contemporary, who argued for the scientific method and the importance of weighing and measuring. 23 Those of orthodox religious persuasion had also come to find justification in conducting myriad scientific analyses of the physical world around them, relying on the statement in the Book of Wisdom (11:20), But you have ordered everything according to measure, number, and weight. 24 De Rhodes, therefore, measured--approximately if not definitively--the coastline of Cochinchina and Tonkin, producing a map that added considerable detail to Europe's previously sketchy knowledge of the geography of the two regions. 25 Following his analytical inclinations another way, de Rhodes made detailed notes about nature--demonstrating both the current scientific spirit and at the same time the gradual European turning away from the traditional conception of nature as a realm of demons and evil powers and therefore a sinful subject upon which to concentrate. 26

Closely connected to de Rhodes's concern with science and mathematics is his concentration on another subject of increasing importance in seventeenth-century Europe, the new applications of the concept of reason. Having been immersed as a student in the contemporary ways of thinking even before leaving Europe in 1619, and prepared by Jesuit experience and practice to take advantage of the emphasis placed on reason in Confucian culture, de Rhodes gives very careful consideration to this subject. In de Rhodes's theology both reason and revelation are vital, revelation being the understanding of religious truth granted by God as contrasted with the understanding achieved through reason. 27 It is, however, the attention paid by de Rhodes to reason that concerns us here as it reflects his European intellectual background. It is clear that de Rhodes believed there was considerable common ground between his own concept of reason and that of his educated listeners and readers in Tonkin and Cochinchina; and his success in appealing to his audience would seem to indicate that he was correct in this belief.

Reason, in de Rhodes's work, plays three distinct roles, each of which sheds valuable light on the relationship of the Jesuit's ideas both to contemporary European thought at the mid-point of the seventeenth century, and to the developing Enlightenment thinking as well. In de Rhodes's writing, the term reason refers in one sense to the traditional concept of innate reason provided to all human beings, enabling them to understand certain truths. Reason also refers to a methodology, the long-accepted means of reaching conclusions through systematic analysis; and, in addition, in a new seventeenth-century sense, reason constitutes a principle that informs all of life, ruling out superstition and that which does not conform to the physical laws of the universe or to demonstrable truth.

The use of the reasoning process as a methodology was, of course, not new in the seventeenth century. It had been brought to a high level of development by the medieval schoolmen who were experts at deducing truths from the accepted body of dogma through close logical arguments. What was innovative in the seventeenth century was the use of the reasoning process to arrive at truth from the analysis of facts, specifically from observed natural phenomena, rather than from commonly accepted metaphysical truths. 28 When de Rhodes uses the term reason to indicate a methodology, a critical way of thinking, he at times combines with it the newer concept of reason, the firm reliance on the physical laws of nature. Clear demonstrations of de Rhodes's way of combining these meanings come out in his intense opposition to what he saw as pandemic superstition among the Cochinchinese and the Tonkinese.

While de Rhodes was remarkably open to many cultural practices that differed from his own, demonstrating, as noted earlier, ideas of cosmopolitanism that were quite advanced for the time, beliefs that he saw as flying in the face of demonstrable truth were simply not acceptable to him. Among the ideas he combatted most forcefully were those connected with the widespread popular faith in magic and sorcerers. De Rhodes describes with some scorn, for instance, the belief in the need for court mathematicians to select propitious times for the ruler to perform certain actions, such as attacking an enemy. 29 In addition, he battles the belief in propitious places, such as the place of burial for one's parents, especially for royalty. If the correct burial place was not found, he reports critically, it was believed that the ruling family could lose its right to the throne. 30 De Rhodes also opposed the superstitious basis for the general recognition of the need to pay any debts contracted during the year by New Year's Day lest evil befall one's household. 31 And he took both philosophical and personal exception to the popular notion that the Western missionaries had caused a drought, and that he himself was a sorcerer whose breath could cast a spell on those to whom he spoke. 32

The belief in the need at the end of each year to provide elaborate, painted paper clothing for the deceased, and then to burn it, seems especially to exasperate de Rhodes. He develops a scientific criticism of the custom, pointing out that the belief that the burnt paper clothing will be of value to the dead does not conform to the known laws of the physical universe. When the Tonkinese explain that with the burning, the paper clothes change into usable items of apparel for the departed, de Rhodes and his colleagues make this testy response:

Yes, certainly . . . they change--partly into ashes and partly into flame; which then of the two parts do you send, the ash or the flame? If it's the ash, they'll be cold under ash: if it's the flame, they'll burn under such hot clothing. 33

De Rhodes is not unaware of the fact that some of his own religious convictions may appear to the Cochinchinese and Tonkinese to be as irrational as their convictions are to him. He once even reports candidly the application of the term superstition to his own faith, noting that the Viceroy of Cochinchina ordered a certain Christian sympathizer to keep his own religion and quit all Christian superstitions. 34 But de Rhodes, as we shall see, uses the argument that Christianity is in fact the religion of reason to negate any such critical ideas.

While de Rhodes firmly supported the developing Western view that the physical laws of the universe could serve as a criterion for ruling out superstition, reliance on immutable laws of the universe was far from absolute for him as for other seventeenth-century Europeans. 35 De Rhodes's conviction that the powers of good and evil continually intervene in human affairs helped him in his missionary work by making possible a highly significant area of common ground for him and his listeners. Descriptions of encounters with both forces abound in de Rhodes's accounts of everyday life in Tonkin and Cochinchina. De Rhodes's scorn for the magicians or sorcerers, who personify for him the evils of superstition, intersects with his belief in the interference of the Devil and of lesser demons when he describes several women who were possessed. As a Westerner with specialized knowledge, de Rhodes was sometimes asked to help such people. Discussing two Cochinchinese women who were said to have supernatural powers, de Rhodes comments that they were able to do things that they would have been incapable of doing if that evil spirit, the Devil, hadn't lent his strength and malice thereto. 36 The missionary describes one of the women, considered to be a phythoness, or prophetess, and explains the process by which the devil, working with magicians, could enter a woman's body and then speak through her. By practicing this evil trade, de Rhodes notes, this particular woman had made a great deal of money. 37 But eventually she became permanently possessed. De Rhodes's account here and his description of the fate of another pythoness and her diabolical art in Tonkin 38 imply that these women co-operated willingly with the magicians and ultimately, therefore, with the powers of evil. De Rhodes's use of the phrases in the servitude of the Devil and commerce with hell 39 in speaking of pythonesses supports the assumption that the women acted of their own free will. These were cases, therefore, not of simple possession, but what through most European eyes of the period would have been instances of possession combined with witchcraft; possession was considered to be an involuntary condition in which an evil spirit entered into a person who was thereafter not responsible for his or her actions, while witchcraft, in contrast, involved a willing agreement to work with the powers of evil. A few cases involving both possession and witchcraft appear in court records in France. 40

In his attitude toward the pythonesses de Rhodes can be seen to be well ahead of his times: in both instances he expresses a compassionate outlook. In the case of the Tonkinese woman, who had previously given up her trade and become a Christian and who then involuntarily became possessed again, this might seem only natural, as her second condition had developed against her will. But in the case of the Cochinchinese pythoness too, de Rhodes is sympathetic. He refers to her, as she prepares for exorcism, as the good women; he also commends her for taking care, after her recovery, never to give entry again to the evil guest who mistreated her so. 41 De Rhodes's outlook in both cases appears to be that people in this situation deserve to be cured or liberated from their bondage to the devil; he places no blame on them, nor does he mention the need for chastisement.

This belief was particularly advanced for the time. In the period when these incidents occurred, the late 1620's in Tonkin and then the early 1640's in Cochinchina, the prevailing attitude in Europe toward people thought to be co-operating intentionally with the Devil was strikingly different from that of de Rhodes; the persecution of witches was by the 1620's at a very high point. 42 Although some questioning of the concept would indeed occur at various points throughout the seventeenth century, the craze would not die out until the century's end. 43 The recommendation of treatment rather than punishment had in fact been advanced by a few courageous individuals before de Rhodes. Montaigne, for example, skeptical about witchcraft as he was of much else, expressed the opinion, after speaking to a woman accused of being a witch, that the medicinal herb hellebore would be more appropriate for her than hemlock. 44 And in the 1580's the faculty of law at the University of Heidelberg decried the death penalty for witchcraft; they argued that it was better to cure the soul than to torture and kill the body. 45 Yet this view was highly exceptional in the years when de Rhodes encountered the women accused of witchcraft in Tonkin and Cochinchina. His narratives, presenting to European readers in an unsensational but firm manner the idea of humane treatment even for people who are considered to have been in league with the powers of evil, may well have played their part in the sea change of attitude toward witchcraft that was beginning at about the time his work was published.

De Rhodes's concern with supernatural powers emerges in his preoccupation with superior powers of good as well as those of evil. The attention given to angels, for example, in his Catechism, reflects perhaps the Jesuit's keen appreciation of the fact that his followers in Tonkin and Cochinchina, accustomed through their own culture and religion to beliefs in supernatural beings, would be receptive to this aspect of Christian doctrine. 46 Dramatic testimony to the supernatural powers of good appears in de Rhodes's many reports of miraculous happenings among his followers. Accounts of the sick being healed abound. De Rhodes's catechists receive credit for numerous miracles; in one town in Tonkin, de Rhodes notes, six catechists cured 272 people who were ill. Elsewhere in Tonkin some blind individuals recovered their sight, and two deceased persons were brought back to life. 47 Relating these events, de Rhodes makes clear, however, the contrast between such supernatural interventions of the power of good, and of evil as well, and what he considered irrational superstition--beliefs in what was lucky or unlucky, faith in the ability of so-called sorcerers to determine these attributes and to predict the future, and indulgence in habitual practices that directly contradicted the laws of the physical universe.

A second use of the term reason, that referring specifically to a method of argumentation, emerges particularly clearly in de Rhodes's Cathechismus, the text that he is thought to have written in Macao between 1636 and 1645 48 Earlier missionaries had in fact composed a catechism in Vietnamese, but the work is believed to have been brief and not highly developed. 49 De Rhodes evidently felt the need for a work that would provide better instruction through more detailed explanations of Christian truths: 50 his own catechism comprised 315 pages of text in the original Latin and Cochinchinese bilingual edition. 51 Having already taught in Tonkin and Cochinchina for about four years when he began the work, de Rhodes developed what he found to be a practical method of explaining Christianity to his prospective converts. He followed this instructional system in the Catechismus, explaining first the principles that he had found to be the most easily grasped and then moving to those which his audience generally found more difficult to understand. 52

De Rhodes was also familiar by this time with the methods of the religious and philosophical leaders in Cochinchina and Tonkin; he knew how heavily the Confucian apologists in particular relied on logical, systematic reasoning in their philosophical and theological disputations, and he knew how to confute their arguments, using the same technique. This skill in reasoning and argumentation came naturally to de Rhodes, of course, as his legacy from Ignatius of Loyola. Ignatius' Spiritual Exercises, a work distinguished by close reasoning, with which de Rhodes, like all Jesuits, was quite familiar, was in some respects a model for his own Cathechismus. 53

It is natural then for de Rhodes in his Cathechismus to explain his faith through carefully reasoned argumentation. We find such phrases as we deduce clearly, 54 and it is necessary to conclude. 55 Quite frequently de Rhodes reasons by means of analogies based on everyday subjects familiar to his readers, showing once again both his practical approach and his exceptionally good knowledge of his audience. In his Divers voyages de Rhodes discusses his use of this method, telling of an exchange he once had in Cochinchina with a pagan with very good sense. 56 Pleased with a question that the man put to him, which brought up a problem that had in fact troubled Saint Augustine, de Rhodes explains to his European readers: I took care not to answer him with scholastic subtleties that might have encumbered his mind. I decided to give him a little comparison that satisfied him. This comment reminds the reader that de Rhodes, trained in scholastic theology, still remained close to the traditional ideas, but was able dramatically to break away from the older methods as he adapted himself to the requirements of the task at hand.

An analogy in the Cathechismus that deals with government, a topic of particular interest to an educated audience, many of whom were themselves government functionaries, provides an example of de Rhodes's method of reasoning. He reports that the Tonkinese and Cochinchinese sometimes ask, why, if they revere God, can they not also revere idols as occupying a position below that of God. In government, they argue, they honor the king, but below him they respect the magistrates and other officials. De Rhodes replies that what this proves is that in addition to honoring God, we should honor the saints, who are the friends of God and intercede for us. Pagan idols, in contrast, are nothing other than demons, rebelling against God. They cannot move God in our favor, but can provoke Him to punish us justly. De Rhodes, therefore, indicates, without stating so explicitly, that the analogy of the questioners is faulty. Those who honor a rebel or deserter, he concludes, no doubt earn the king's anger for themselves. 57

De Rhodes's Cathechismus, though influenced by the methodology of the Spiritual Exercises, differs nonetheless in purpose and content from the earlier work, the catechism being intended as an explanation of the faith for non-believers, while Ignatius' work offers spiritual guidance for professed Christians. The Cathechismus also shows a marked dissimilarity from other catechisms well known in Europe in de Rhodes's day. The divergences reveal again the Jesuit's acute sensitivity to the needs and expectations of his Southeast Asian audience. In contrast to de Rhodes's work, for example, are the immensely popular catechisms by the Jesuits Diego de Ledesma (), Peter Canisius (), and Laurence Vaux (). 58 These works, intended for persons who already had at least some knowledge of the faith, set forth and explained Christian doctrine; but unlike de Rhodes's work, they did not use close reasoning as a method of presentation.

Much closer to de Rhodes's treatise, in respect to the use of rational argument to explain Christian doctrine, is the first Christian catechism in Chinese, The True Record of the Lord of Heaven, completed by the Jesuit missionary Michele Ruggieri in 1584. 59 Ruggieri, grounded like de Rhodes in Ignatian logic and the Jesuit proselytizing formula, approached the Chinese users of his catechism in ways that would be most convincing to them, emphasizing both the reasoning method and also reliance on innate reason as a means of apprehending truth. That one sees God through reason, not the eyes, 60 was as basic to Ruggieri's catechism as it would be to that of de Rhodes about a half-century later.

A second Jesuit work explaining Christianity to the Chinese was The True Meaning of the Lord of Heaven (T'ien-chu shih-i), published in Peking in 1603 by Matteo Ricci. 61 This was a reworking of Ruggieri's catechism into what specialists on the work today see not as a true catechism but as a pre-evangelical dialogue. 62 The book not only had immediate success but came to have lasting influence in both China and other parts of Asia. Although Ricci had significantly altered the approach found in Ruggieri's work, he had retained the emphasis on the role of reason in human life. 63

It is not known whether or not de Rhodes's knowledge of Chinese was adequate for him to read and make a detailed study of these works in Chinese, but through his contacts with other Jesuits in Macao he would surely have known about Ricci's catechism and perhaps Ruggieri's as well. He had, in fact, seen a Christian work in Chinese that had made its way to Tonkin which was most likely Ricci's catechism. 64 De Rhodes's own converts among the Tonkinese and Cochinchinese came from a background--Confucian, Buddhist, and Taoist--similar to that of Ruggieri's and Ricci's audiences; it is not surprising, therefore, that de Rhodes also chose to place considerable emphasis on the concept of mankind's innate reason and to make use of reason in his presentation. The role of reason is, however, less significant in de Rhodes's work than it is in Ricci's. De Rhodes's format also differed from that of Ricci, who followed Chinese methodology, employing a dialogue structure for his explanations of Christian principles, frequently posing rhetorical questions which required the reader to agree with the writer. 65 De Rhodes, in contrast, chose as his format a series of eight discussions or talks which often relied on the use of reason through logical argumentation, the approach that had already proven successful for him in speaking to Cochinchinese and Tonkinese audiences.

The concept of innate reason, the idea that all human beings are endowed with the ability to understand certain basic truths, constitutes the third meaning of the term reason in de Rhodes's work. De Rhodes refers in his Cathechismus to natural reason impressed in our hearts by God, 66 and he speaks of the rational souls of human beings. 67 This kind of reason serves then as the underpinning for specific doctrinal matters; worshiping the creator and Lord of Heaven and Earth, for example, is comformable to reason. 68 De Rhodes is appealing here not only to the Confucian elite, known for their reliance on reason, but to educated Buddhists as well. The emphasis on reason, he notes elsewhere, produced successful results with the Priests of the Idols (a term he uses for Buddhist priests). 69 These listeners, he explains, . . . were all delighted when I pointed out to them our religion's conformity to right reason, and admired above all God's Ten Commandments, finding that nothing more reasonable could be uttered or more worthy of being laid down by the Supreme Monarch of the world. 70

De Rhodes's emphasis on reason no doubt contributed significantly to his success in gaining converts. At the same time, although he would never have anticipated such a result, his appeal to the Tonkinese and Cochinchinese sense of the power of reason may also have contributed, in its own way, to the shaping of ideas in Europe. While the number of general readers in Europe who would carefully study the Latin text of the Cathechismus was, of course, limited, this work, along with de Rhodes's narratives of travel, which would have been more widely read--in combination with the works of other contemporary missionaries and travelers in China--may well have come to have an effect quite different from anything de Rhodes could have expected: the growing appeal for some in Europe of reliance on reason as a major support for religion, and the consequent weakening, though not the exclusion, of revelation as Christianity's basis. This process would lead eventually in the eighteenth century to the development of the concept of natural religion in which revelation played no part. 71

Scholars today point to de Rhodes's many significant achievements for the Church. Among these were innovations in the structure of the mission in Vietnam itself: building on the concept of native catechists, a system begun by other missionaries in Asia which de Rhodes had used with great success, he then pressured for and achieved for the first time in Southeast Asia European bishops who could proceed with the ordination of a native clergy. In addition to these structural innovations, which led to the autochthonism of the Roman Catholic Church in Vietnam, de Rhodes provided the Church not only with carefully written accounts of his work, but also with his Cathechismus, a resource that would be used for centuries by the Roman Catholic Church in Vietnam.

But his greatest achievement for the Church is surely that of wining over great numbers of Cochinchinese and Tonkinese converts. While it is difficult to assess the accuracy of the numbers of converts that were reported--in Tonkin, for example, 6,700 in the first three-year period that De Rhodes worked there 72 --the extraordinary growth of the Church both in Tonkin and in Cochinchina during the time of de Rhodes's mission work is unquestioned. Without doubt, his charismatic personality, which emerges strongly through his narratives, accounts for much of this success. But, in addition, one must credit the many deliberate strategies he employed in order to achieve his aims. Among these the appeal to the Cochinchinese and Tonkinese, especially the elite, with demonstrations of Western European science and new ways of thinking was of utmost importance. Through his skills in mathematics and astronomy, his personal curiosity about nature, his insistence that reason calls for the laws of physics to be used as a means of gauging and opposing superstition and the occult--one finds the Jesuit representing the most contemporary European ideas. Like Ricci in China, de Rhodes used a generous amount of this European intellectual flavoring to season the spiritual repast he prepared for his hosts.