Charity and Compassion: A Comparative Study of Philosophy of Friendship Between Thomistic Christianity and Mahayana Buddhism

Abstract

In the current era, when civilizations are in constant conflict and humankind is facing a series of serious existential crises, there is an urgent need for universal love to unite humankind. As models of world religions, Christianity and Buddhism provide rich intellectual resources for the construction of such universal love. Regarding Thomistic Christianity, its philosophy of friendship has gradually achieved a dual transformation from virtue-oriented to love-oriented, and from God-centered to human-centered. In the case of Mahayana Buddhism, its philosophy of friendship has evolved with the “Humanistic Buddhism” movement, increasingly demonstrating a compassionate spirit of saving the world. By comparing Thomistic Christianity with Mahayana Buddhism, we can see that although they exhibit different models of friendship, their main developmental trends are consistent. Both are committed to demonstrating a human-centered model of friendship, both emphasize the value of self-reduction in friendship, and both demonstrate the unique and irreplaceable role of religion in friendship. The goal of the philosophy of friendship is universal love and harmonious development of civilizations, while its future development depends on the joint efforts of contemporary religious scholars and philosophers.

1. Introduction

At a time when science and technology and the organizational capacity of society are becoming increasingly advanced, humankind is still not free from the quagmire of war, and the vision of world peace is still quite distant from us. In addition to the ongoing Russian–Ukrainian war and the escalating Palestinian–Israeli conflict, the major Powers are tensely pitted against each other in various political, economic, cultural, and military aspects. The current situation in the world is, as Teilhard de Chardin describes it, “The further the thinking individual advances in his own thought, the more impervious he apparently becomes to others … he then no sees any answer to the need for universal communion” (Teilhard de Chardin 1972, p. 61). With nationalism on the rise and the process of globalization blocked, is there a bright future for humankind with a common destiny?

In the face of the current critical situation, we are in dire need of an equal and universal love of friendship to unite all humankind to build our common home. Due to the widespread influence of capitalism, the general tendency towards individualized development and the worship of money and materialism, this universal love can hardly find a basis in today’s secular society and ethics. But in religions that emphasize transcendentalism, this universal love can find a solid theoretical foundation. Christianity and Buddhism, as models of world religions, contain rich intellectual resources for the construction of such a universal philosophy of friendship. Although there are differences in the practice, nature, and purpose of friendship between the two religions, these do not prevent Christianity and Buddhism from learning from each other through religious dialogues to adjust and enhance each other’s philosophies to suit today’s society and make positive contributions to unifying human beings and resolving various conflicts and contradictions.

Due to the enormous scope of Christianity and Buddhism, as well as the diversity of their reflections on friendship, we can only select one representative view from each religion for comparison. In terms of Christianity, we have chosen Thomistic Christianity, as Thomism has gradually become the orthodoxy of Catholicism since the Middle Ages, and contemporary Neo-Thomism is also thriving; in terms of Buddhism, we have chosen Mahayana Buddhism because it is the most widely spread and influential form of Buddhism in China. Furthermore, the “Humanistic Buddhism” (人间佛教) movement that emerged from it in modern times has driven the modernization of Buddhism, with its concept of “engaged practice” (入世修行) gaining increasing popularity. Both Thomism and Mahayana Buddhism have had a huge impact on their societies’ ideas and culture. It is quite meaningful to conduct a comparative study of the philosophy of friendship in both to explore their theoretical effectiveness in the common dilemmas facing humanity today, as well as the possibilities and directions for future development.

2. The Formation of Thomistic Christian Philosophy of Friendship

From the very beginning of the philosophy of friendship, it was conceived as capable of uniting all people, and Aristotle said, “Friendship seems also to hold cities together… and when people are friends, they have no need of justice, while when they are just, they need friendship as well” (Aristotle 2004, p. 144). Next, Aristotle attributes the essence of friendship to virtue, which he defines very clearly, “Since it is a virtue or involves virtue, and is an absolute necessity in life. No one would choose to live without friends, even if he had all the other goods” (Aristotle 2004, p. 143).

It is important to note that Aristotle’s philosophy of virtuous friendship is not universal and is valid only at stages of history. In ancient Greece and Rome, city-states were essentially cities serving as independent nations, indicating their limited territory and population. Moreover, in his work Politics, Aristotle excluded many slaves from being objects of civic friendship, stating, “A slave is a piece of animate property of a sort; and all assistants are like tools for using tools” (Aristotle 1998, p. 6). In Aristotle’s conception, a large population of slaves was not an object of friendship; they only needed to obey. In a specific polis (city-state), if the ruling “citizens” maintained friendship among themselves, the polis could achieve long-term stability. Between city-states, if the ruling “citizens” established friendly relations with each other, humanity could achieve universal unity. It is not difficult to imagine that the friendship among a small group of privileged classes were used to support the unity of human society. This is the basic model of Aristotle’s philosophy of friendship. He added, “Love and friendship, then, are found most of all among people like this, and in their best form. Naturally, such friendships are rare, because people of this kind are few” (Aristotle 2004, p. 147). To this, Cicero agrees, “That friendship cannot exist except among good men… this thing called friendship has been so narrowed that the bonds of affection always unite two persons only, or, at most, a few” (Cicero 1964, pp. 127–29). These arguments argue strongly with the above point that although true virtuous friendship is extremely scarce in the city-states, Aristotle still believes that it is sufficient to hold the city-states together.

The Aristotelian model was soon challenged by the development of the times. With the expansion and annexation of city-states, people from different regions, colors, nationalities, cultures, and beliefs mixed, and with the awakening of democratic consciousness, more people gained citizenship, and because of the differences in them, they naturally had different “virtues”, so how should they get along with each other? As Emile Durkheim observed, “If the ancient Romans had not the broad conception of humanity that we possess today, it is not because of any defect attributable to their limited intelligence, but because such ideas were incompatible with the nature of the Roman state. Our cosmopolitanism could no more come to the light of day than a plant can germinate on a soil unable to nourish it” (Durkheim 1997, p. xxvi). Because of the limitations of the concept of virtue, people will only combine into separate communities based on the criterion of being in the same situation, and “Nor do worthless people expect to be friends with the best or the wisest” (Aristotle 2004, p. 152). In this way, it seems that Aristotle’s idea of friendship does not lead the city-states towards unity, but towards separation.

Transcendental or secular, spiritual or material, collective or individual—which is more in line with the requirements of virtue? Different societies and cultures breed different virtues, and the lack of uniformity in the standards of virtue makes it difficult for a society to unite more people by means other than conquest. The philosophy of friendship centered on virtue is difficult to truly unite people, not only because of the diversity of virtue, but also because it lacks the power to motivate people to act. As we see in everyday life, most people admire saints, but few strictly demand of themselves the standards of saints. In this situation, Christianity introduced the love of God into the philosophy of friendship, inspiring and elevating it, and injecting a powerful internal force into uniting people, which directly led to the shift of the philosophy of friendship from virtue-centered to love-centered.

Christianity’s love-centered philosophy of friendship manifests itself in two ways. One is to emphasize God’s love for humanity, thereby weakening the practical importance of friendship between people, as humanity can achieve eternal peace solely through God’s love, and the other is to emphasize the friendship of men in God’s Presence, wherein God, the neighbor, and the self are closely united by the power of God’s love. Incidentally, these two ways correspond to two significant Christian masters, St. Augustine and St. Thomas Aquinas.

In Augustine’s view, the core and essence of friendship is Caritas—a composite love, as Anders Nygren pointed out, “The meeting of the Eros and Agape motifs produces a characteristic third which is neither Eros nor Agape, but Caritas” (Nygren 1953, p. 451). Augustine’s view is based on reality. From a human perspective, love and being loved in the human world are both expressed in a composite form, that is, in friendships, there are both noble and selfless aspects, as well as vulgar and selfish aspects. No one can separate these two aspects; only by combining them can we achieve Caritas. Nygren correctly observed, “whether one single concept can comprise all that Augustine means when he speaks of Caritas … How this was possible is ultimately less a logical than a psychological problem” (Nygren 1953, p. 452). The advantage of this approach is obvious: it fully respects the complex coexistence of good and evil in the human heart and is therefore easily accepted. However, it also has a characteristic, namely that the goodness or badness of friendship is determined by the object of love, as Nygren argues, “That love is right which sets its desire on a right object—that is, on an object which really can satisfy man’s needs; that love is wrong which is directed to a wrong object—that is, to an object which is unable, or only apparently able, to satisfy man” (Nygren 1953, p. 483). So, right love is called Caritas, and wrong love is called Cupiditas. We will see that it is because of this that Caritas is distancing itself from universal love.

Augustine explicitly states that “What we see, then, is that two societies have issued from two kinds of love. Worldly society has flowered from a selfish love which dared to despise even God, whereas the communion of saints is rooted in a love of God that is ready to trample on self” (Augustine 1952, p. 410). This statement plays a guiding role in his philosophy of friendship, containing two aspects: on the one hand, it directly separates sacred friendship from secular friendship; on the other hand, considering the characteristic of Caritas, Augustine belittles or even rejects secular friendship.

The separation of sacred friendship from secular friendship is known from the conceptual analysis of the City of God, while the reasons for the rejection of secular friendship are a bit more complex. Augustine declared that “The heavenly and earthly, intermingled as they have been from the beginning and are to be until the end of time… Both of these cities alike make use of temporal goods, and both are equally afflicted by temporal ills—but how different they are in faith, how dissimilar in hope, how unlike in love! This will go on until they are to be separated in the Last Judgement” (Augustine 1954, p. 182). Since, as Augustine declared, the two cities are mixed from beginning to end, and the only thing that can be trusted is the eternal Word of God, then worldly friendships necessarily carry the danger of diverting men from the ways of God, and the upright are equally prone to fall into evil through the ties and temptations of worldly friendships. This is precisely what Cupiditas refers to. Augustine said, “The more friends we have… the more widely stretched are our heartfelt fears, lest any of the mountainous miseries of life befall them… What is far harder to swallow is our fear that they may fail us in faithfulness, turn to hate us and work us harm” (Augustine 1954, p. 207). Thus, the only reasonable choice is a cautious rejection of worldly friendship, “there is at all events nothing in the primary definition of the idea of Caritas to make the introduction of love to neighbor necessary” (Nygren 1953, p. 501). Augustine added, “Indeed, we would rather hear that our friends are dead. Yet here is another source of sadness, for the death of those can never leave us free from grief whose friendship during life was a solace and delight” (Augustine 1954, p. 208).

While Augustine’s rejection of secular friendship is based on the concepts of Caritas and Cupiditas, he seems to have gone even further in the case of the gap between God and human. Let us consider only the friendship between God and man. Since the concept of friendship is not free from the tendency of two-way interaction, each person may receive a different “revelation” from his own communication with God, and consequently, there will be a great variety of pronouncements as to which is more in line with the Word of God. To eliminate the source of contradiction and preserve human unity, Augustine recognized only a one-way friendship from God to man, stating that “This joy in God is not like any pleasure found in physical or intellectual satisfaction. Nor is it such as a friend experience in the presence of a friend… It is more like the eye rejoicing in light” (Augustine 1952, p. 36). For the same reason, this one-way friendship extends to the angels, and “Nothing but the great mercy of God can save a man from mistaking bad demons for good angels, and false friends for true ones, and from sufferings the full damages of this diabolical deception” (Augustine 1954, p. 209).

Augustine’s transformation and development of the ancient Greek philosophy of friendship was extremely important. He introduced the concept of God, transcended geographical and cultural limitations, united the masses who converted to Christianity, and warned and exhorted them when they indulged in worldly friendship, so that they would follow the right path to salvation. However, in today’s globalized world, his philosophy of Caritas has become impotent when confronted with the “other” who is also strong in his convictions, for it both rejects worldly friendship and eliminates the possibility of discussing God in good faith with the “other”. In view of its unidirectional nature, Augustine’s philosophy of Caritas has even played a negative and obstructive role in today’s atmosphere of dialogue among religions on an equal footing and of mutual enrichment.

In an imperfect analogy, Augustine’s concept of Caritas requires that one direct both love for neighbors and love for God towards the singular target of God, just as an anti-aircraft gun aims at its objective, otherwise there is a risk of falling into sin. This process requires people to exert continuous effort, making the realization of Caritas extremely difficult. Even Augustine himself said, “But I could not fix my gaze thereon; and my infirmity being struck back, I was thrown again on my wonted habits” (Augustine 2005, p. 114). It is already very difficult to always love God, so loving one’s neighbor—which is indispensable to universal love—becomes an obstacle to loving God. As mentioned above, Augustine’s dilemma regarding friendship is directly related to his psychological definition of Caritas. In contrast, Aquinas synthesized Aristotle’s philosophy of friendship and discussed Christian love from a sociological perspective, arguing that whether it be virtuous friendship, utilitarian friendship, or hedonistic friendship, all contain varying degrees of God’s love, which people need to seek rather than to bear. Thus, the core and essence of friendship shifted from Caritas to charity, thereby overcoming Augustine’s dilemma to a certain extent.

Compared to Augustine, Aquinas’ philosophy of charity appears to be more theoretically open and inclusive and has had a greater impact on later scholars. We summarize Aquinas’ enhancement of his predecessor’s philosophy of friendship in the following aspects:

Firstly, Aquinas overcomes the split between the sacred and the secular by uniting charity with virtue, and he establishes a definitive standard for virtue that resolves the contradictions that arise from the lack of uniformity in the standard. First of all, Aquinas gives an affirmative answer to the question of whether “charity is friendship,” arguing that “Since there is a communication between man and God, inasmuch as He communicates His happiness to us, some kind of friendship must needs be based on this same communication … The love, which is based on this communication, is charity” (Aquinas 1947, p. 1688). Together with Aristotle’s proposition that “friendship is a virtue,” charity and virtue are naturally harmonized. Second, Aquinas’ notion of charity builds a bridge between God and humanity, bridging the gap between the sacred and the secular, but his idea is so surprising that even Aristotle himself would have explicitly rejected it. In Aristotle’s view, true friendship is mutual care for the purpose of virtue or goodness, and thus some degree of equality is indispensable for friendship, and “For friendship can survive many losses, but when one side is removed at a great distance—as god is—then it is no longer possible” (Aristotle 2004, p. 152). It can be said that Aquinas achieved the connection between the divine and the secular by eliminating the equality of friendship, but this also laid hidden dangers for the practice of friendship. Third, Aquinas attributes goodness to the existence of God, establishing a definitive and unified standard for the virtues. On the one hand, Aquinas attributes goodness to existence, “The essence of goodness consists in this, that it is in some way desirable… Now it is clear that a thing is desirable only in so far as it is perfect, for all desire their own perfection. But everything is perfect so far as it is actual. Therefore, it is clear that a thing is perfect so far as it exists; for it is existence that makes all things actual” (Aquinas 1947, p. 29). On the other hand, he attributes goodness to God, “Since God is the first effective cause of all things, it is manifest that the aspect of good and of desirableness belong to Him; and hence Dionysius attributes good to God as to the first efficient cause, saying that God is called good ‘as by Whom all things subsist’.” (Aquinas 1947, p. 36) Combining these two aspects, it is not difficult to conclude that God’s existence is the supreme good.

Secondly, Aquinas greatly enhanced the openness and inclusiveness of friendship by establishing a logical chain between the two commandments of “love of God” and “love of neighbor” through charity. First, Aquinas states that “God is in all things; not, indeed, as part of their essence, nor as an accident, but as an agent is present to that upon which it works… Now God causes this effect in things not only when they first begin to be, but as long as they are preserved in being; as light is caused in the air by the sun as long as the air remains illuminated” (Aquinas 1947, p. 45). The idea that “God is present in all things” gave a powerful impetus to opening to more strangers and building friendships, and Aquinas’ philosophy of charity thus reversed the elitist tendencies of Aristotle’s philosophy of friendship. Second, the relationship between “love of God” and “love of neighbor” is a profound and central theme in the Christian tradition, to which Aquinas replies, “Since what we ought to love in our neighbor is that he may be in God. Hence it is clear that it is specifically the same act whereby we love God, and whereby we love our neighbor” (Aquinas 1947, p. 1712). Not only that, but according to the logic of charity, love of one’s neighbor extends even to love of one’s enemy, “And in this sense charity requires that we should love our enemies, namely, that in loving God and our neighbor, we should not exclude our enemies from the love given to our neighbor in general” (Aquinas 1947, p. 1719). Combined with these two points, Aquinas’ charity is open not only to God, but also to the neighbor, even the enemy, and becomes a truly universal love of friendship.

Thirdly, Aquinas logically distinguishes a hierarchy of charity and secular friendship, thereby constructing an order of virtue that provides positive guidance for the perfection and redemption of humanity. First, Aristotle noted that “It seems that not everything is loved, but only what is worthy of love, and this is what is good, pleasant or useful. What is useful, however, would seem to be what is instrumental to some good or pleasure” (Aristotle 2004, p. 145). Of course, we could go on to say that things that give real pleasure are also good. Based on what is worthy of love, Aristotle distinguishes three kinds of friendship and is broadly able to unify all three into virtuous friendship. However, these three kinds of friendship derive from the empirical observation of everyday life, and they are relatively discrete; i.e., we will be rewarded for whichever kind of friendship we experience in our daily lives. Aquinas, however, gives these three kinds of friendship a continuity that abates the significance of friendships other than charity by arguing that “In the movement of the appetite, the thing desired that terminates the movement of the appetite relatively … is called the useful; but that sought after as the last thing absolutely terminating the movement of the appetite … is called the virtuous… but that which terminates the movement of the appetite in the form of rest in the thing desired, is called the pleasant” (Aristotle 2004, p. 35). Second, Aquinas distinguishes between the two forms of charity, completing the construction of the virtuous order, “Consequently the love with which a thing is loved, that it may have some good, is love simply; while the love, with which a thing is loved, that it may be another’s good, is relative love” (Aquinas 1947, p. 944). For Aquinas, charity is both a continuum and yet has both absolute and relative forms, and as it moves to the Absolute, there is a newness of being, like a “quantum leap”.

Although Aquinas’ philosophy of charity is theoretically well developed, it still faces some challenges in practice, especially in today’s context of dialogue among diverse civilizations. Perhaps the greatest challenge lies in the fact that Aquinas’ philosophy of charity is God-centered rather than human-centered.

On the one hand, although Aquinas, by means of the movement, made charity a path of ascent towards the perfect presence of God, it also placed a heavy moral constraint on the people. In the question, “Whether charity admits of decrease?”, Aquinas says, “Now on our side there is a reason why charity is withdrawn entirely from us by God, namely when we love something in contempt of God … For he who turns from God deserves that charity be taken away from him by God” (Aquinas 2008, p. 76). This can create a dilemma when faced with the culture of the Other and the attraction of secular life, i.e., people may worry that their interest in worldly things might inadvertently lead them astray from God, and Teilhard adequately portrays the heart of the people struggling, “Either the Christian will repress his taste for the tangible and force himself to confine his concern to purely religious objects… he will dismiss the evangelical counsels and decide to lead what seems to him a complete and human life… and this is the most usual case, he will give up any attempt to make sense of his situation; he will never belong wholly to God, nor ever wholly to things” (Teilhard de Chardin 1960, p. 52).

On the other hand, a God-centered philosophy of charity has a clear apologetic bias, which is detrimental to the effectiveness and urgency of dialogue between civilizations. As Donald K. Swearer said, “If we approach people of the other religious persuasions purely from the standpoint of advocacy, if we believe that our particular perception of religious truth is the only correct one, then genuine dialogue does not take place. What occurs is merely a series of monologues” (Swearer 1977, p. 41). This point may not have been a problem for Aquinas himself; “But if we speak of perfect Happiness which will be in our heavenly Fatherland, the fellowship of friends is not essential to Happiness” (Aquinas 1947, p. 812). However, now that humanity faces a common crisis of survival, dialogue and friendship seem to be our only way forward.

The Christian philosophy of friendship had basically taken shape by the time of Aquinas, but its God-centered and apologetic nature meant that it was still far from realizing universal love. In its subsequent development, the Christian philosophy of friendship gave rise to diverse trends. For example, John Calvin, John Wesley, Clive Staples Lewis, and Gene Outka all reflected deeply on friendship. As far as the Thomistic stream is concerned, Karl Rahner played a crucial role in its development. As a key theological advisor to the Vatican Council II, Rahner’s ideas had a profound influence on the council’s documents, as expressed in Nostra Aetate on universal friendship: “The Church reproves, as foreign to the mind of Christ, any discrimination against men or harassment of them because of their race, color, condition of life, or religion” (Vatican Council II 1965, Nostra Aetate, art. 5). These achievements have actively promoted the establishment of friendship and mutual learning between religions and between religions and secular others in practice. The philosophy of friendship of Rahner will be discussed in the subsequent comparison section. It is gratifying that the continuous efforts and progress of Christianity are bringing us closer to achieving universal love, as John Cobb predicted, “Christ as Truth will transform the truths of all other traditions even as they transform ours” (Cobb 1998, p. 143).

3. The Theory and Practice of the Philosophy of Friendship in Mahayana Buddhism

Friendship is not only a religious theme but also a social and cultural one, because its effects and influences can be expressed most intuitively through the thinking and habits of people in their daily lives. In the Western world, where Christianity is strong, it is difficult for people to escape the influence of religious culture in their daily lives. But in China, the situation is quite different. Dialectical materialism and historical materialism have always been the official ideology of the new China, and in a society where atheism is the main theme, the influence of religion—even Buddhism, which is also characterized by atheism—on Chinese society is relatively limited. Even under these circumstances, some overly classical Buddhist ideas have managed to penetrate deeply into the hearts of the people and have had a tremendous impact on generations of Chinese. This article is not only to compare the ideas of Christianity and Buddhism but also to consider the authenticity of friendship as a social phenomenon.

Therefore, in selecting materials, we choose Mahayana Buddhist Scriptures that are familiar to ordinary people and relevant to the main idea of this article, such as Jingang Bore Boluomi Jing (金刚般若波罗蜜经 the Diamond Sutra), Bore Boluomiduo Xin Jing (般若波罗蜜多心经 the Heart Sutra), Miaofa Lianhua Jing (妙法莲华经 the Lotus Sutra), Dizang Pusa Benyuan Jing (地藏菩萨本愿经 the Earth Store Sutra), and Liuzu Fabao Tan Jing (六组法宝坛经 the Platform Sutra of the Sixth Patriarch;1 in choosing interpretations of the Scriptures, we mainly refer to the viewpoints of Yinshun (印顺),2 who has had a great influence on both Chinese and foreign academics.

Yinshun was one of the main proponents of the “Humanistic Buddhism” movement in modern China. He liberated Buddhism from its theological and abstract nature and returned it to its humanistic and empirical roots, forming a theoretical system with both academic depth and practical significance, which provided valuable intellectual resources for the transformation of modern Buddhism. From an ideological perspective, Yinshun, through his examination of the history of Indian Buddhist thought, emphasized that the Madhyamaka school was closest to the Buddha’s original intent. He advocated that “dependent origination and emptiness” (缘起性空) were the fundamental principles of Buddhism, denied the existence of entities, and advocated the use of wisdom to eliminate self-attachment and attachment to phenomena. He upheld the fundamental principle that “the Buddha is among us, yet he is still human” (佛在人间而犹是人也) (Yinshun 2011c, p. 101) emphasizing that Buddhism should be rooted in real-world society and achieve a pure land on earth through the purification of hearts and society. He actively promoted the concept of religious dialogue, fostering mutual learning between Buddhism and Confucianism, Christianity, and other cultures, thereby setting an example for the harmonious development of diverse civilizations. From a practical perspective, Yinshun advocated a human-centered approach, promoting compassion, wisdom, and social responsibility. He emphasized that Buddhism should address contemporary social issues such as education, charity, and ecology. He stressed that the “Bodhisattva Practice” must balance personal cultivation with altruistic endeavors and proposes the concept of “Buddhist-inspired families,” (佛化家庭) (Yinshun 2011a, p. 41) aiming to foster social harmony through the practice of family ethics and integrate Buddhist teachings into daily life. He personally embodied the “Bodhisattva Practice,” (菩萨行) making significant contributions in areas such as founding Buddhist colleges, reforming Buddhist education, engaging in cross-cultural dialogue, disaster relief and public welfare, and preserving cultural heritage and ecological conservation.

Through the following comparative study, we will find that the philosophy of friendship between Buddhism and Christianity manifests itself in two very different modes:

Firstly, regarding the practice of friendship, unlike Christianity which emphasizes the pursuit of the highest goodness of virtue and the love of God, Buddhism emphasizes the transcendence of the suffering of all beings, and this is the “compassionate action” that Buddhism preaches. Thus, Christianity’s concept of friendship is characterized by competition and optimism, while Buddhism is characterized by cooperation and a desire to benefit all sentient beings.

The root of this difference is that Christian friendship is attributed to God’s commandments, whereas Buddhist friendship is born out of human self-nature. In Christian culture, the highest standard of human behavior is to conform to God’s testament with mankind, and the testament points to the sublime God Himself, so Christian friendship is naturally upwardly oriented. In Buddhist culture, there is no concept of the one true God, and human beings need to rely on their own strength if they want to be free from suffering and happy. However, human strength varies greatly among individuals. Bodhisattvas (菩萨), with great wisdom, wish to fulfill all sentient beings, and Da Zhi Du Lun (大智度论 the Great Treatise on Perfect Wisdom) states, “To hold and rejoice in merit and virtue, sharing with all sentient beings” (持是随喜福德, 共一切众生), whereas ordinary people have limited mental powers and can only care about themselves, “These are secondary merits, all achieved through self-regulation, self-purification, and self-liberation” (是二乘福德, 皆为自调、自净、自度) (Da Zhi Du Lun 大智度论 the Great Treatise on Perfect Wisdom Volume 61 Section 39 CBETA 2025. R1, T25, no. 1509, p. 488a16–17). Thus, structurally, Buddhist friendship is downwardly compatible.

Buddhism’s fundamental aspiration to liberate sentient beings from suffering and establish harmonious friendships with others stems from its profound insight into the nature of universal suffering. Moreover, Buddhism views these sufferings as cosmological in nature, integral components of the world. As the Lotus Sutra clearly states, “The three realms are not at peace; they are like a house on fire, full of suffering and terrifying, and there is always the sorrow of birth, old age, sickness, and death, such as the fire that burns unceasingly” (三界无安, 犹如火宅, 众苦充满, 甚可怖畏, 常有生老, 病死忧患, 如是等火, 炽燃不息) (Miaofa Lianhua Jing 妙法莲华经 the Lotus Sutra Volume 2 Section 3 CBETA 2025. R1, T09, no. 262, p. 14c22–24). Because of the deep sense of suffering in the world, the wise naturally develop sincere sympathy for others from within, and this empathy for the suffering of others is the very meaning of compassion. In recounting the reasons for the Buddha’s becoming a monk, Yinshun pointed out:

“The Buddha went out into the wilderness to wander… not tolerating the hunger, thirst, and barrenness of the poor peasants, and having to go on with their work; not tolerating sentient beings killing each other; not tolerating the persecution of old age and death… was to integrate his own suffering with that of all sentient beings, and to think of his own suffering when seeing the suffering of others.”

(世尊到野外去游散… 不忍贫农的饥渴劳瘠, 又不得不继续工作；不忍众生的自相残杀；不忍老死的逼迫… 是将自己的痛苦与众生的痛苦打成一片, 见众生的痛苦而想到自己的痛苦)

(Yinshun 2001, p. 4)

Moreover, the ultimate development of Buddhist compassion is to promote the concept of “unrelated compassion”, i.e., to show compassion to strangers with whom one does not even have any relationship. According to the Great Treatise on Perfect Wisdom, “Ordinary beings are bound by sentient conditions; Disciples and Solitary Buddhas are initially bound by sentient conditions, but later by Dharma (法) conditions; The Buddhas, having perfectly practiced ultimate emptiness, are thus called ‘unconditioned’.” (凡夫人, 众生缘; 声闻、辟支佛及菩萨, 初众生缘, 后法缘; 诸佛善修行毕竟空, 故名为无缘) (Da Zhi Du Lun 大智度论 the Great Treatise on Perfect Wisdom Volume 40 Section 4 CBETA 2025. R1, T25, no. 1509, p. 350b26–28). Those who never meet can still feel genuine compassion. Buddhism, based on compassionate actions, is striving to establish the most universal friendship in the world that transcends blood ties and beliefs.

Secondly, regarding the object of friendship, unlike Christian friendship, which focuses on self-improvement, Buddhist friendship emphasizes more on selflessness and altruism. It can be said that Christian friendship has not essentially departed from the tradition of self-love, and its object is still the self, whereas Buddhist friendship is essentially altruistic, and its object is all beings.

The root cause of this difference lies in their distinct worldviews. For Christianity, all things and life forms in the world were created separately by God, as clearly stated in Genesis. However, for Buddhism, all things and life forms in the world are not created by God but arise from dependent origination, which Buddhism calls the “Law of Dependent Origination.” To explain this concept clearly, Yinshun gave an example: “When we see a fruit tree, we know it must have grown, flowered, and fruited through various conditions such as seeds, fertilizer, water, and temperature. It certainly did not come from nothing, nor was it born from other plants, minerals, or rocks” (如见一果树, 则知必由种子、肥料、水分、温度等种种关系, 此树才能长成开花结果, 决不是从空而生, 也不是从别的草木金石生) (Yinshun 2001, p. 76). Following this, Yinshun explained the law of Dependent Origination:

“This is the cause and condition, from which that effect arises. Therefore, the simple definition of Dependent Origination is that things arise due to conditions… There is nothing absolute; everything exists only in relative relationships. This is the conclusion Buddha reached through observing the universe and life. And thus, one realizes that all this is neither accidental nor created by God.”

(此为因缘, 有彼果生, 故缘起的简单定义, 即是缘此故彼起… 没有一些绝对的东西,—切要在相对的关系下才能存在, 这是佛陀观察宇宙人生所得的结论。也就因此, 悟得这一切不是偶然的, 也不是神造的)

(Yinshun 2001, p. 79)

For Buddhism, dependent origination is the ultimate way to understand the universe. It is not only manifested in a single thing but in all things. It does not target a single object but all objects. When dependent origination is taken to its extreme, we arrive at the Buddhist concept of “emptiness”. The Platform Sutra of the Sixth Patriarch states, “Emptiness can contain the sun, moon, stars, mountains, rivers, all vegetation, good and evil people, good and evil laws, heaven and hell—everything exists within emptiness. The human nature is empty, just like this” (空能含日月星辰, 大地山河,—切草木, 善人恶人, 善法恶法, 天堂地狱, 尽在空中。世人性空, 亦复如是) (Liuzu Fabao Tan Jing 六组法宝坛经 the Platform Sutra of the Sixth Patriarch Volume 1 CBETA 2025. R1, T48, no. 2007, p. 339c26–28). In terms of the root cause of the creation of the universe, Buddhist emptiness is equal in utility to the Christian God. What is very ingenious is that Buddhism uses emptiness to embody the vastness of the universe, while Christianity presents the abundance of the universe through love. They allow humans to experience the duality of the infinite through complementary paths.

Due to Christianity’s distinction between God and created beings, differences between different entities arise. Consequently, the proposition that the universe was created from nothing naturally emerges, along with the distinction between necessity and contingency. However, Buddhism deeply believes in the law of dependent origination. From a Buddhist perspective, all phenomena in the universe have been interdependent since ancient times. Therefore, Buddhism naturally does not accept the proposition that the universe originated from nothing and denies the Christian-style distinction between necessity and contingency. For Buddhism, the necessity embodied in the law of dependent origination is based on the necessity of “cause-and-effect” relationships, rather than the necessity based on entities as in Christianity. Yinshun said, “Everything that is known is a product of dependent origination. Dependent origination and its arising are the principles of both theory and practice” (现实所知的一切, 是缘生法。缘起与缘生, 即理与事) (Yinshun 2010b, p. 82).

It can be said that the law of dependent arising refers to all phenomena in the universe as the results. The production of results must have its causes, which are embodied in the law of dependent origination. Dependent origination and dependent arising, inferring causes from results, are the laws of necessity upheld by Buddhism. Christianity advocates the necessity of God and the contingency of creation, while Buddhism advocates the necessary connection between events and principles, yet preserves the contingency of events themselves. The difference between the two lies here.

In Christian culture, God, self, and others form a hierarchical structure of substance and necessity. From this perspective, it is natural to regard friendship as self-love—love of God in one’s own existence. However, in Buddhist dependent origination, there is no concept of isolated substance. Therefore, Buddhist friendship does not have a Christian-style God or individual standpoint, and Buddhism explicitly denies the practical utility of these standpoints. Yinshun pointed out, “It is only by not perceiving the world from the standpoint of the ego that one can truly understand the world and save it” (不从自我的立场看世间, 才能真正的理解世间、救护世间) (Yinshun 2001, p. 5). Since Buddhism does not have a substantial standpoint to discuss friendship, what standpoint should it take? Yinshun said, “The sentient being’s self is a conditioned entity of matter and spirit. All activities of the external world and the inner mind must be understood from the existence of sentient beings. Only by taking sentient beings as the foundation can the activities of the external world and the inner mind be determined for their existence and meaning” (有情自体, 是物质与精神的缘成体。外界与内心的活动,—切要从有情的存在中去把握。以有情为本, 外界与内心的活动, 才能确定其存在与意义) (Yinshun 2001, p. 24). Obviously, Buddhism’s stance on friendship is based on the profound insight into the law of dependent origination, holding a naturalistic standpoint. When discussing friendship, Yinshun pointed out, “Due to the lack of self-entity in sentient beings, they are interdependent and mutually conditioned. Since no being exists independently, and all sentient beings are not separate from each other, one can achieve ‘no resentment, no anger, and no hatred’.” (由于有情无自性, 是相依相缘相成, 自己非独存体,一切有情也不是截然对立的, 所以能 ‘无怨、无嗔、无恚’) (Yinshun 2001, p. 135) In Buddhism, there is no concept of self-entity; my phenomena and all phenomena of the universe are necessarily intertwined due to the law of dependent origination, and since my phenomena are not in opposition to others, naturally compassion for others arises, and then it is not difficult to understand that sentient beings have become the objects of Buddhist friendship.

Thirdly, in terms of the results pursued by friendship, unlike Christianity, which emphasizes the gain in friendship, Buddhism promotes a “not to gain” kind of friendship.

Through the discussion above, we can know that Christianity continues the Aristotelian tradition of dividing the grades of friendship according to the different results of friendship. The highest rank is undoubtedly virtuous friendship, followed by utilitarian friendship, and again by joyful friendship. The downside is that the results of friendship replace friendship itself, even though this is completely contrary to Aquinas’s emphasis on the importance of love in friendship, leading to the disappearance of pure friendship. This creates a paradox, and it has been verified by the fact that people who go in search of friendship always get something else that has nothing to do with friendship but instead move further away from true friendship. For Buddhism, friendship can be seen as an event resulting from dependent origination. It embodies the principle of interdependent arising, which demonstrates the inseparability of principle and phenomenon. Friendship does not create outcomes; it is the outcome itself. Therefore, “not to gain” should be the characteristic of pure friendship.

Why seek friendship when it gives one nothing? Because, bringing nothing is precisely the highest wisdom of Buddhism, and friendship is the natural choice that arises from understanding this wisdom.

Firstly, “not to gain” liberates one from suffering and afflictions. The Heart Sutra states, “Because there is nothing to gain, Bodhisattvas rely on Perfect Wisdom, and thus their minds have no obstructions. With no obstructions, there is no fear, they are free from delusions and dreams, and ultimately attain Nirvana (涅槃)” (以无所得故, 菩提萨埵依般若波罗蜜多故心无挂碍。无挂碍故, 无有恐怖, 远离颠倒梦想, 究竟涅槃) (Bore Boluomiduo Xin Jing 般若波罗蜜多心经 the Heart Sutra Volume 1 CBETA 2025. R1, T08, no. 253, p. 849c13–15). The ultimate pursuit of Buddhism is to comprehend the truth of dependent origination and achieve Nirvana. The greatest obstacle to Nirvana is the difficulty people face in overcoming the negative impact of ego-existence. If one believes that actions in this world bring gains, it undoubtedly reinforces ego-existence, contradicting the principle of dependent origination. Since dependent origination has proven that the self is empty, one should not view the self and others in isolation; benefiting others and benefiting oneself are fundamentally unified. Take friendship as an example: if people expect benefits from friendship, they will inevitably use their friendships for advantages, thus distorting their thoughts and actions. Friendship will then deteriorate, and suffering and afflictions will follow. Only by understanding the wisdom of “not to gain” in friendship can people reveal their true selves and intentions, allowing friendship to bring pure joy.

Secondly, “not to gain” enables one to understand the equality of friendship. The Diamond Sutra states, “When the Buddha attained Ultimate Wisdom, did he achieve it through not to gain? The Buddha replied, ‘Indeed, indeed’… This Dharma is equal, without distinction of high or low, and is called Ultimate Enlightenment”3 (佛得阿耨多罗三藐三菩提, 为无所得耶? 佛言: ‘如是, 如是’… 是法平等, 无有高下, 是名阿耨多罗三藐三菩提) (Jingang Bore Boluomi Jing 金刚般若波罗蜜经 the Diamond Sutra Volume 1 CBETA 2025. R1, T08, no. 235, p. 751c20–28). Regarding “not to gain” as the profound essence of Ultimate Enlightenment holds deep philosophical significance. Not only is there nothing to gain in terms of benefits but also in terms of virtues. From the perspective of dependent origination, all phenomena in the universe arise due to interdependent conditions. This fundamental principle of dependent origination reveals the emptiness of the universe. If the universe itself is empty in nature, how can individual phenomena such as self and others remain constant and immutable? Realizing the emptiness of self and others leads to the understanding that nothing can be added to this essential nature, thus deeply experiencing the true meaning of equality among all sentient beings. Take friendship as an example: the more noble the friendship, the more it allows one to return to one’s true nature and the more it allows one to experience one’s own completeness. Buddhist friendship is based on the complete equality of all sentient beings; therefore, neither benefits nor virtues can be obtained. In contrast, Christian friendship is built on the insignificance and deficiency of the self. Thus, it is understandable that they pursue benefits and virtue development by sacrificing the equal relationship of friendship.

Thirdly, the realization of “not to gain” spontaneously leads to the development of friendship. The Earth Store Sutra says, “If I do not first liberate all sentient beings from suffering, and lead them to peace and happiness, and ultimately to enlightenment, I shall never aspire to become a Buddha” (若不先度罪苦, 令是安乐, 得至菩提, 我终未愿成佛) (Dizang Pusa Benyuan Jing 地藏菩萨本愿经 the Earth Store Sutra Volume 1 Section 4 CBETA 2025. R1, T13, no. 412, p. 780c11–12). If Hell is not emptied, I shall not become a Buddha, which is the great vow made by Ksitigarbha (地藏) Bodhisattva. It profoundly embodies the truth of “not to gain.” Helping suffering beings brings no benefit to Ksitigarbha Bodhisattva himself but rather slows down his own progress towards Buddhahood. However, from the perspective of the emptiness of all phenomena, as an enlightened being, by helping others realize emptiness and experience their own perfection, he gradually liberates all sentient beings from suffering and afflictions, which carries immeasurable merit. Yinshun commented on this, stating, “By engaging in the deeds one undertakes, one inspires ordinary people to practice the Bodhisattva path. All those benefits others and serves the interests of others is virtuous conduct, and it inevitably enhances and benefits oneself as well. In the Bodhisattva path, benefiting others and benefiting oneself are unified” (依自己所作的事业, 引发一般人来学菩萨行。为他利他的一切, 是善的德行, 也必然增进自己,利益自己的。利他自利, 在菩萨行中得到统一) (Yinshun 2001, p. 137). Take friendship as an example: A true friend will be saddened by your sorrows and happy by your successes, and never expects to receive anything in return from you; comparatively, we will feel that we have experienced the same misfortunes because of the misfortunes of our friends, and we will feel that we have succeeded because of the successes of our friends, and I believe that these are all things that a person who has a close friend is able to experience. Therefore, this experience of not wanting anything from a friend naturally gives rise to noble acts of friendship.

In summary, the characteristics of compassionate action, dependent origination, and not to gain constitute Buddhism’s comprehensive philosophy of friendship, which differs significantly from Christian philosophy of friendship. For Christianity, the pursuit of happiness and benefits constitutes secular friendship, while the pursuit of virtue and God constitutes charity, forming a hierarchical structure of friendship. However, for Buddhism, all forms of friendship are manifestations of dependent origination, making them equal. Moreover, since all friendships can help sentient beings understand the emptiness of the universe, they can help alleviate suffering and bring happiness. Although Buddhist friendship does not have the same strong purposefulness as Christian friendship, it still arises from sufficient reasons, as Yinshun said, “All sentient beings, especially humans, not only develop a sense of compassion due to the interdependent nature of existence but also often unconsciously and intuitively share the joys and sorrows of all beings and humanity. Whether for oneself or others, there is an intuitive inclination towards equality and harmony, with a common source of aspiration” (一切众生, 特别是人类, 不但由于缘起相的相依共存而引发共同意识的仁慈, 而且每每是无意识地, 直觉对于众生, 对于人类的苦乐共同感。无论对自, 无论对他, 都有倾向于平等, 倾向于和同, 有着同一根源的直感与渴仰) (Yinshun 2010b, p. 81).

4. The Modern Development of the Philosophy of Friendship in Thomistic Christianity and Mahayana Buddhism

Before continuing our discussion on the modern development of the philosophy of friendship in Christianity and Buddhism, we need to introduce an ancient Chinese anecdote about friendship to illustrate that the philosophy of friendship is not a topic that has been imported from Western philosophy. Friendship is also an important social phenomenon that is independently rooted in Chinese culture and has a long history. According to Karl Jaspers’ theory of the Axial Age, “Until today mankind has lived by what happened during the Axial Period, by what thought and created during that period. In each new upward flight, it returns in recollection to this period and is fired anew by it” (Jaspers 2021, p. 14). Not coincidentally, at the time when Plato and Aristotle came up with their embryonic philosophy of friendship, China, in the same period, had its most classic story of friendship to date for the Chinese. The story of the “Kindred Spirits” (知音) is a well-known one in China, and there are many versions of it, but the most detailed and widespread version is recorded in Lü Shi Chunqiu 吕氏春秋 (The Spring and Autumn Annals of Lü Shi). The story is this:

“Boya played the Qin and Zhong Ziqi listened to him. When he was playing the Qin and his imagination was to be on Mount Tai, Zhong Ziqi said, “How wonderful your playing is! It is as majestic as Mount Tai.” In a moment of contemplation, and his imagination was drawn to flowing water, Zhong Ziqi said, “How wonderful your playing is! It is as surging as flowing water.” When Zhong Ziqi died, Boya broke his Qin and cut its strings, never playing it again for the rest of his life.”

(伯牙鼓琴, 锺子期听之。方鼓琴而志在太山, 锺子期曰, “善哉乎鼓琴！巍巍乎若太山。” 少选之间, 而志在流水, 锺子期又曰, “善哉乎鼓琴! 汤汤乎若流水。”锺子期死, 伯牙破琴绝弦, 终身不复鼓琴).

(Buwei 2007, p. 113)

Lü Buwei’s (吕不韦) interpretation of the story favors Confucianism, “Not only is it true for the Qin, but also for the wise. Even if there are wise people, but no proper etiquette to receive them, how can they fully demonstrate their loyalty? It’s like driving a horse improperly; even a thoroughbred won’t run thousands of miles by itself” (非独琴若此也, 贤者亦然。虽有贤者, 而无礼以接之, 贤奚由尽忠？犹御之不善, 骥不自千里也) (Buwei 2007, p. 113). Meeting over the Qin and promoting the idea that the virtuous should have a noble end, the Confucian interpretation, though enlightening to a certain extent, deviates from the main theme of friendship. Regarding this, Yinshun commented on Confucianism, “Under the family-oriented culture in China, although it expanded to the ideas of ‘all people under the heavens are brothers’ and ‘the world belongs to all’, it was ultimately confined by the narrow concept of ‘family’.” (中国在家庭本位文化下, 扩充到”四海皆兄弟”, “天下为公”, 而终究为狭隘的”家”所拘蔽) (Yinshun 2010b, p. 83) Confucianism interprets the story of the “Kindred Spirits” as the virtuous finding a noble end, with the focus being on the noble end rather than the virtuous themselves. Without proper placement, even someone as virtuous as Confucius would be reduced to a “homeless dog.” As a result, people tend to concentrate on self-preservation rather than benefiting the world. This aligns with Yinshun’s logic of expanding from family to society, reflecting a prioritization of family over nation. Just as Christianity sublimated the ancient Greek philosophy of friendship, so Buddhism has illuminated the Chinese philosophy of friendship. The most appropriate interpretation of the story of the “Kindred Spirits” can be found in Buddhism. Simply put, the meeting of Boya and Zhong Ziqi embodies the principle of dependent origination, without their chance encounter, there would be no subsequent story; Boya’s playing the music of “High Mountains and Flowing Water” and Zhong Ziqi’s listening to him demonstrates their mutual compassionate behavior. When the music ends and the listener departs, Boya broke his strings after Zhong Ziqi’s death, showing the profound truth of non-attachment. What was established between Boya and Zhong Ziqi was pure friendship, and it is precisely because of its purity that their story has been able to transcend millennia and touch generations of Chinese people. It can be said that a comparative study of the Christian and Buddhist philosophies of friendship has both practical and theoretical significance.

Focusing on the modern philosophy of friendship, what progress has been made in Christianity and Buddhism?

Regarding the Thomistic stream of thought, Karl Rahner undoubtedly had the most significant influence on the modern philosophy of friendship. Building upon Kant and Heidegger, he transformed Thomistic philosophy, elevating the philosophy of friendship to a remarkably mature level. Since the Vatican Council II up to the present day, his ideas have become the mainstream in guiding dialogue between Christianity and other religions, as well as secular others. In religious dialogue, his most famous concept is “Anonymous Christian,” a notion that is both highly influential and controversial. The most representative criticism comes from Hans Kung, “Anyway, in reality, they—Jews, Muslims, Hindus, Buddhists and all the others, who know quite well that they are completely ‘unanonymous’—remain outside. Nor have they any wish to be inside. And no theological sleight of hand will ever force them, against their will and against their desire, to become active or passive members of this Church… The will of those who are outside is not to be ‘interpreted’ in the light of our own interests, but quite simply respected” (Kung 1976, p. 98). Obviously, Hans Kung’s literal criticism of “Anonymous Christian” is unfair. As we will demonstrate in the following discussion, Rahner’s “Anonymous Christian” is one of the highly productive paths to universal love.

Firstly, Rahner brought Christian friendship back from heaven to earth. After incorporating Heidegger’s ideas, Rahner pointed out that what humans need to face is not God in the context of realism but God in the context of existentialism. In Aquinas’ model, God’s presence in friendship is closed and distant, placing heavy moral constraints on friendship. In Rahner’s model, God’s presence in friendship is intimate and inseparable, liberating humans from their constraints and granting them freedom. Rahner said, “the existential of man’s absolute immediacy to God in and through this divine self-communication as permanently offered to freedom can exist merely in the mode of an antecedent offer, in the mode of acceptance and in the mode of rejection” (Rahner 1987, p. 128). Therefore, compared to Aquinas’ philosophy of friendship, which is God-centered, Rahner’s philosophy of friendship is human-centered. Accepting Heidegger’s “Dasein” means accepting the “thrownness” of human beings, and Rahner agreed with this, stating, “But that means that man is essentially ambivalent. He is always exiled in the world and is always already beyond it” (Rahner 1994, p. 406). As a result, people are often overwhelmed by anxiety, fear, and loneliness, and they need the care, support, and warmth of friends to overcome these struggles. Thus, friendship, which was irrelevant to the traditional Thomist school, gained a sense of urgency and importance in Rahner’s work. Rahner’s view is consistent with Mahayana Buddhism’s assertion that “all beings suffer.” As mentioned above, suffering has cosmological significance in Buddhism, and it has the same effect for Rahner. To transcend worldly suffering, Mahayana Buddhism teaches people to see the suffering of all beings and develop compassion. Rahner, on the other hand, calls on people to learn from each other and listen to God’s Word together.

Secondly, Rahner’s philosophy of friendship not only encourages Christians to be open but also demonstrates God’s openness. Compared to Heidegger’s austerity, Rahner’s existentialism offers more warmth and greater hope, making him in this sense a more progressive thinker. According to Rahner’s definition, human beings are hearers of the Word, and “man is the existent thing, who stands in freedom and as freedom before the God of a possible revelation which, if it occurs, appears in history in the word” (Rahner 1969, p. 162). Just as Buddhists have the right to liberation and Nirvana in the face of a world filled with suffering, Christians equally have the right to listen to the truth and attain salvation. This hope is real and urgent, which has been confirmed by Rahner’s efforts. According to Rahner’s definition, human beings are completely open, and this openness further extends to an invitation to other religions and secular others, thus giving rise to the concept of the “Anonymous Christian.” Rahner pointed out that “It is possible, then, to envisage a man who is in possession of that self-imparting of God called grace as the innermost heart and center of his existence, one who has accepted this in unreserved faithfulness to his own conscience… Admittedly I do regard the term ‘Anonymous Christian’ as inescapable so long as no one suggests a better term to me” (Rahner 1976, p. 292). In the context of contemporary religious dialogue, rather than establishing a religious pluralism that stands above all religions but belongs to no tradition as the basis for dialogue, Rahner’s approach of breaking down barriers from his own faith and inviting others to understand the mysteries of Christianity is clearly more sincere. This completely open state, when developed to its ultimate form, is embracing the entire world, as Rahner said, “Thus every venture into the world shows itself to be borne by the ultimate desire of the spirit for absolute being” (Rahner 1994, p. 407). Rahner’s argument for the openness of faith is highly consistent with the Mahayana Buddhist concept of “One Mind, Two Gates (一心二门).” Dasheng Qixin Lun (大乘起信论 Mahayana Awakening of Faith Treatise) states, “There are two gates: one is the gate of the true nature of mind, and the other is the gate of mind’s arising and ceasing. These two gates encompass all phenomena” (一者, 心真如门, 二者, 心生灭门。是二种门, 皆各总摄一切法) (Dasheng Qixin Lun 大乘起信论 Mahayana Awakening of Faith Treatise Volume 1 CBETA 2025.R1, T32, no. 1666, p. 576a5–7). In other words, the worldly and the transcendental are not completely opposed to each other. They present different landscapes depending on the orientation of one’s heart. When people turn towards the path of Nirvana or the word of God, they can naturally distance themselves from suffering and afflictions. From the perspective of complete openness, the friendship offered by Rahner is sincere and beautiful.

Thirdly, Rahner’s philosophy of friendship restores the principle of equality in friendship. Rahner’s critics argue that “Anonymous Christian” embodies Christian centrism and hegemony. However, reviewing the conceptual logic of this term, as demonstrated above, it becomes clear that these are misunderstandings. Far from being a self-expanding concept, “Anonymous Christian” is a self-reducing one. We should not treat “Anonymous Christian” as a prescriptive concept or an imposed identity on others, but rather as a blessing or a gift, which might be closer to Rahner’s original intention. This is consistent with the Mahayana Buddhist concept of “all sentient beings are Buddhas (凡夫即佛).” The Platform Sutra of the Sixth Patriarch states, “Ordinary beings are Buddha, afflictions are Bodhi (菩提). The previous thought of delusion makes one an ordinary being, while the subsequent thought of enlightenment makes one a Buddha. Attachment to phenomena in the previous thought creates afflictions, while detachment from phenomena in the subsequent thought leads to Bodhi” (凡夫即佛, 烦恼即菩提。前念迷即凡夫, 后念悟即佛。前念着境即烦恼, 后念离境即菩提) (Liuzu Fabao Tanjing 六祖法宝坛经 the Platform Sutra of the Sixth Patriarch Volume 1 Section 2 CBETA 2025.R1, T48, no. 2008, p. 350b27–29). For Mahayana Buddhism, all sentient beings are fundamentally equal to Buddhas, and for Rahner, all people are hearers to God’s Word. This restores human equality in the context of interreligious dialogue. Thus, we can understand the genuine friendship between Rahner and the Japanese Zen master Nishitani. When the master asked Rahner, “How about if I call you an ‘anonymous Zen Buddhist’?” Rahner replied, “I feel myself honored by such an interpretation, even if I am obliged to regard you as being in error or if I assume that, correctly understood, to be a genuine Zen Buddhist is identical with being a genuine Christian” (Rahner 1983, p. 219).

Overall, Rahner’s transformation of Thomas’ philosophy was quite successful, as he fully revealed the true intentions behind Thomas’ philosophy of charity.

Regarding Mahayana Buddhism, modern philosophy of friendship has developed alongside the “Humanistic Buddhism” movement. Traditional Mahayana Buddhism, due to its long-term detachment from reality and excessive metaphysical speculation, had fallen into decline with weakening monastic orders and fading faith. To reverse the trend of Buddhism’s emphasis on death and ghosts, and shift the focus towards life and society, Master Taixu was the first to propose the ideal of “Life Buddhism(人生佛教).” His verses express the essence of “Life Buddhism,” “As suffering boils in the world, with wisdom and compassion we save all. We aspire only to the Buddha’s way, perfection lies in human character -When man becomes enlightened, the Buddha is made, this is true reality” (众苦方沸腾, 遍救怀明达。仰止唯佛陀, 完就在人格, 人成佛即成, 是名真现实) (Taixu Dashi Quanshu 太虚大师全书 The Complete Works of Master Taixu Volume 20 CBETA 2025.R1, TX32, no. 20, p. 258a4–5). Yinshun, while building upon “Life Buddhism,” sought common ground while respecting differences, and systematically developed the “Humanistic Buddhism” theory, becoming one of the major forces driving the modernization of Mahayana Buddhism.

In promoting the development of “Humanistic Buddhism,” obstacles may arise when shifting from “post-mortem liberation” to “present-world care,” which raises issues related to “compassionate action.” As the doubts Yinshun had to face pointed out:

“The Buddhist spirit of compassion and altruism is indeed extremely great! However, who can be altruistic? How can one benefit others? This is not possible without one’s own great enlightenment and liberation … Then the rest of the public are not qualified to be altruistic, and the only thing left to do is to seek self-interest. This is the reason Buddhism claims to be compassionate and altruistic but has few acts of compassion!”

(佛教的慈悲利他精神, 确是极伟大的! 然而, 谁能利他呢? 怎样利他呢? 这非先要自己大彻大悟, 解脱自在不可… 那么其他的大众都不够利他的资格, 唯有急求自利了。这似乎就是佛教口口声声说慈悲利他, 而少有慈悲事行的原因吧!).

(Yinshun 2010b, pp. 92–93)

Regarding this issue, Yinshun’s answer is to make friends widely, engage in civilized dialogue, and, on this basis, promote Buddhism to establish a new worldwide culture. Under the influence of such a new culture, it would be natural for people to practice “compassionate action” in their daily lives. Yinshun pointed out that, “Rather than replacing the old with a new set or promoting Buddhism by overthrowing other religions, it is about eliminating the entitative worldview and dissolving the self-centered outlook on life through the promotion of Buddhist teachings. Instead, we should elucidate universal principles and cultivate a new global consciousness for humanity” (不是以一套新的来取代旧的, 也不是打倒其他宗教而推行佛教, 而是从发扬佛法中, 化除实体的世界观, 消融自我中心的人生观；阐扬世界性原理, 培养人类世界性的新意识) (Yinshun 2010a, p. 234). In this light, Yinshun’s plan requires the participation of more people, and thus the friendship of the human world and the universal love contained within that friendship become necessary prerequisites for the birth of the new culture.

5. The Confluence of the Philosophy of Friendship Between Christianity and Buddhism

The development of the modern philosophy of friendship is the result of joint efforts across cultures. The emergence of universal love is inseparable from human collaboration; therefore, the future of philosophy of friendship shows a trend of confluence. Another philosopher deeply rooted in the Thomistic school, Teilhard de Chardin, provided us with solutions to the challenges of dialogue and development in the philosophy of friendship. He presented us with a counter-intuitive proposition, “Union differentiates,” while people believe that union creates uniformity. Teilhard pointed out:

“Whether it be the cells of a body, the members of a society or the elements of a spiritual synthesis—union differentiates. In every organized whole, the parts perfect themselves and fulfil themselves … following the confluent orbits of their centers, the grains of consciousness do not tend to lose their outlines and blend, but, on the contrary, to accentuate the depth and incommunicability of their egos”.

(Teilhard de Chardin 1976, p. 262)

There is wisdom in what Teilhard said. As a paleontologist, he saw through millions of years of fossil records how the same species developed different organs and survival modes; as a philosopher, he realized that only by integrating into a collective and receiving its support could an individual’s personality truly shine. The situation is no different at the religious level. Only through dialogue and mutual learning can various religions reveal the truth to humanity, as Friedrich Max Müller, the founder of comparative religion, once said, only knowing one, knowing none.

Humanity is facing an unprecedented situation; the joint development of Earth and rapid transportation advancement have made us a physical union, while the spread of internet and cultural exchange have made us a spiritual union. So, according to Teilhard, for the philosophy of friendship, should humans passively allow themselves to be differentiated, leading to sharp opposition in interests and beliefs as seen in today’s chaotic global conflicts, or should they actively seek dialogue and understanding, contributing to building universal love with their irreplaceable strength? The latter should be the direction we should strive for, should it not?

Indeed, Christianity and Buddhism can make efforts in the following three aspects to jointly promote the development of the philosophy of friendship:

Firstly, continue to promote self-reducing friendship and create an environment for the harmonious development of civilizations.

For Buddhism, Mahayana Buddhism has always advocated a worldview of dependent origination and a life philosophy that dissolves the self. The “Humanistic Buddhism” ideology continuously calls for mutual understanding and tolerance among religions, jointly creating a new culture of equality, freedom, and compassion. Therefore, Buddhism has a very practical comparative advantage in terms of self-reducing. Not surprisingly, we have also found a similar tradition of self-reducing in Christianity through comparison. According to the Bible (John 3:30) (NIV), John the Baptist taught the crowds that, “He must become greater; I must become less.” It is true that the only way to witness that all glory, praise, and power go to God is for humankind itself to withdraw. In the modern era, there are more scholars like Rahner who support the Christian tradition of restoring self-reduction. Jürgen Moltmann said, “We might call this missionary aim to ‘infect’ people, whatever their religion, with the spirit of hope, love, and responsibility for the world” (Moltmann 1977, p. 152). John Hick said, “According to our big picture, the world religions are human responses to that absolute Reality, embodying its ‘impact’ upon us. And they all report this impact—whether they speak of revelations, theophanies, enlightenment, illumination, awakening—as benign, loving, compassionate, merciful, as well as totally demanding” (Hick 1999, p. 165). It is true that by treating other religions in a tolerant rather than hostile manner and giving them room to live, one can realize that God’s wisdom shines through all religions.

Secondly, continue to promote human-oriented pure friendship, making the practice of friendship prevalent everywhere.

Due to the influence of ancient Greek substantial thinking patterns, Thomistic friendship always oriented towards immortality and greater necessity, which undoubtedly centered on God. This God-centered friendship leads to the loss of friendship, as we have already demonstrated. However, modern philosophers represented by Rahner turned to human-centered friendship, focusing on people’s real-life interactions, thereby salvaging the purity of friendship. For Buddhism, no matter how long a friendship lasts or how pure the friendship is, it is perishable, as are all things that arise in the universe. Interestingly, if one stops striving for the permanence of friendship, it can become eternal like the story of the “Kindred Spirits.” Not coincidentally, some Christian philosophers hold a similar view. Alfred North Whitehead believed that there was nothing eternal and unchanging in the universe and that everything, including God, was in constant becoming. In his book Process and Reality, he wrote, “That the actual world is a process, and that the process is the becoming of actual entities. Thus, actual entities are creatures” (Whitehead 1978, p. 22). Admittedly, it is absurd to seek necessity in something as doomed as friendship, and Augustine and Aquinas found nothing but disappointment at the end of their search, so it is not difficult to understand that they both made friendship a vice-phenomenon of virtue. However, Buddhism teaches us that necessity does not have to be eternal. Just like everything in the universe arises and ceases due to dependent origination, the process of its arising and ceasing is inevitable. Now, we no longer live in small city-states but in a global village, facing billions of neighbors. This is the necessary condition that contemporary people must deal with. Teilhard said, “The age of Nations is past, the task before us now, if we would not perish, is to build the earth” (Teilhard de Chardin 1965, p. 16). In order for each other to continue to survive, human beings must be united, and thus friendship acquires an unprecedented necessity.

The fundamental form of Buddhist friendship is selfless altruism, but it also faces practical issues. Due to the widespread misunderstanding of dependent origination’s ultimate truth as emptiness, and the misconception of Buddhist practice as merely retreating into seclusion, people tend to intellectually contemplate the law of dependent origination without practicing compassion in their daily lives. Mahayana Buddhism indeed has shortcomings in the practice of friendship. Compassionate actions, dependent origination, and not to gain should be an integrated whole, but they are often separated in practice. People emphasize the emptiness of dependent origination while neglecting compassion and joyous giving. In this regard, Buddhism should learn from Christianity. Based on the commandment of loving others as oneself, Christians continuously practice concrete acts of friendship in daily life; they are giants in action. As Thomas Merton insightfully observed, “For the Buddhist, life is a static and ontological fullness. For the Christian it is a dynamic gift, a fullness of love” (Merton 1968, p. 138).

Thirdly, continue to leverage the irreplaceable role of religion in promoting friendship, thus contributing to world peace.

In secular friendships, people are united for a variety of reasons, but the usual result is a greater degree of self-centeredness and a greater degree of selfishness. In this regard, Teilhard commented that “It may be that in our human inter-relationships we encounter our fellows only ‘tangentially’, through our interests, through our functions, or for business dealings—in either case, we are generally working, or seeking, enjoying ourselves or suffering, without loving” (Teilhard de Chardin 1960, p. 122). Erich Fromm noted that “Selfishness and self-love, far from being identical, are actually opposites… It is true that selfish persons are incapable of loving others, but they are not capable of loving themselves either” (Fromm 1956, pp. 60–61). In addition to selfishness, Buddhism also sees the hypocrisy in secular friendships, as Yinshun pointed out, “In society, one cannot help but hide one’s bitterness, one’s true intentions, one’s mistakes, and one’s sins. Over time, even the true self misunderstands itself!” (在社会中, 有不能不隐蔽自己的苦衷, 覆藏自己的真意, 覆藏自己的错误, 覆藏自己的罪恶。久而久之, 连真的自己也误会自己了!) (Yinshun 2011b, p. 5) Our general lack of love and trust in others, and the deficiencies exhibited by secular friendships, are the very obstacles to humanity’s realization of the vision of world peace.

How can humankind get out of the rut when there is no love in friendship? It can be said that without religious revelation, universal love is difficult to achieve in the secular world. Cobb, speaking of the relationship between man and God, stated that “In its openness to the creative love of God, the self receives new possibilities for its own existence that point it away from itself toward wider horizons of interest. Through its openness to the responsive love of God, it receives assurance of its acceptance despite its sin, is freed from preoccupation with itself, and is enabled to turn to others with a disinterested concern for their welfare” (Cobb and Griffin 1976, p. 94). Teilhard, speaking of love, stated that “Resonance to the ALL—the keynote of pure poetry and pure religion… A universal love is not only psychologically possible; it is the only complete and final way in which we are able to love” (Teilhard de Chardin 1976, pp. 266–67). Buddhism gives a similar account of this, with Yinshun noting that “The order of family, country and world exists, but it is also indeterminate… Those who are sincere in becoming a monk are precisely those who have a broad mind, who are not confined to the family circle but are willing to dedicate themselves physically and mentally to all human beings and all sentient beings” (家国天下的次第是存在的, 但也是不定的… 真心出家的, 正是心胸广大, 不拘于家庭圈子, 而愿为一切人类,一切众生而奉献身心的人) (Yinshun 2011b, pp. 91–92). The answer to this question is highly consistent between Christianity and Buddhism, in that under the light of God or through the guidance of wisdom, every individual can transcend the narrow self to embrace the true self and the greater reality. In union with God or all sentient beings, one is freed from the prison of selfishness and hypocrisy, thus inspiring universal love. And this is extremely beneficial for humans to resolve conflicts and contradictions in their increasingly limited living space.

6. Conclusions

Through the discussion above, we can know that the philosophy of friendship is a wealth of thought common to both Christianity and Buddhism, which has had a far-reaching influence on people’s lives and interactions. Nowadays, in the face of the existential crisis of humankind, the Christian and Buddhist philosophies of friendship are like two diverse sources that will eventually merge to form a raging rushing current that will lead humankind across the obstacles and towards a hopeful future.

The comparative study of the philosophy of friendship between Christianity and Buddhism has a double significance. On the one hand, Christianity and Buddhism can learn from each other and complement each other’s strengths and weaknesses by comparing each other, so that they can reach a consensus on the philosophy of friendship, establish a truly universal love in the world, and jointly guide the future of humankind. Christianity should learn from Buddhism that friendship is the most natural human relationship. We should not expect anything more from this natural relationship, thus allowing virtue to grow spontaneously in the process of establishing friendship. Christianity should come out of the confinement of ancient Greek’s substantialism through dialog, and thus recover its original tradition of self-reduction, without which universal love cannot emerge. On the contrary, Buddhism should learn from and be inspired by Christianity, particularly in terms of its spirit of dedication and service, to continue advancing the cause of “Humanistic Buddhism” and strive to build universal friendship. Meanwhile, Buddhism should overcome its tendency towards emptiness through dialogue, maintaining a balance between emptiness and existence and, on this basis, promote its compassionate and benevolent spirit of saving the world.

On the other hand, the comparative study of the two has some positive implications for the course of social history. As Max Weber argues, “One of the constitutive components of modern civilization, was the rational organization of life based on the idea of the calling. It was born out of the spirit of Christian asceticism” (Weber 2012, p. 122). The spirit of Christianity has directly contributed to the development of capitalism; traditional Christian philosophy became an enabler for capital expansion. However, today’s unbridled expansion of capital has plunged humanity into profound disasters. The mutual conflicts between civilizations, the chaotic scramble for resources, and the deteriorating environment are all closely related to this. Fortunately, thanks to the efforts of modern Christian philosophers like Rahner, Thomistic philosophy of friendship has gradually achieved a double leap: from virtue to love, and from God-centeredness to human-centeredness. Meanwhile, through the endeavors of modern Buddhist thinkers such as Yinshun, the concept of “Humanistic Buddhism” has gained increasing influence, attracting more people to participate in “engaged practice.” This brings us closer to achieving universal love. Let the new philosophy of friendship become an inhibitor of capital expansion, leaving room for the harmonious development of all civilizations, and let humanity join hands to build a beautiful earth together.

Citations and reference for the Taishō Tripiṭaka and the Shinsan Zokuzōkyō (Xuzangjing) are based on the corpus of the Chinese Buddhist Electronic Text Association (CBETA). Citations for the Taishō Tripiṭaka are referenced and enumerated according to the volume order, text number, page, column, and line, e.g., CBETA 2022. Q4, T30, no. 1579, p. 517b6–17. Available online: https://cbetaonline.dila.edu.tw/zh/ (accessed on 1 June 2025).