The Relationship between Augustine’s Anthropological Duality and His Doctrine of the Two Cities

Abstract

Augustine of Hippo’s early works distinguish between the earthly human person, driven by worldly desires, and the reborn person, oriented towards heaven. Later, in his monumental De ciuitate Dei (On the City of God), Augustine expands on this distinction, proposing the existence of two cities: the earthly city, characterized by the love of self; and the city of God, characterized by the love of God. This tension between the two loves shapes human understanding of and place in the world. This article explores how the said tension reflects a duality in human nature, tracing the development of the relationship between Augustine’s doctrine of the two cities and his reflections on the dual human nature from his early works to De ciuitate Dei. The article studies whether the duality of human nature mirrors the dichotomy between the ciuitas Dei (city of God) and the ciuitas terrena (earthly city), examining how the conflict between good and evil within individuals and society serves as a model for the conflict between the two cities in Augustine’s doctrine, with a focus on how these concepts are expounded in his earlier writings and articulated in his De ciuitate Dei. It examines how the interaction between these loves manifests in human actions and desires, and shapes our understanding of the good and desirable. Ultimately, this article seeks to address the question of whether the tension between the love of God and the love of self, both in society and in human nature, is capable of harmonious resolution in Augustine’s mindset.

Because Augustine’s doctrine of the two cities offers a powerful framework for understanding the nature of human society and the role of spirituality in it, that doctrine has long captured the attention of scholars. While the interpretation of this doctrine as a mere binary opposition between the earthly and heavenly cities has been critiqued for its simplicity, it is incontrovertible that Augustine initiates his discourse from a definition that is grounded in oppositional terms. He clearly emphasizes a distinction between the two cities that is based on their differing orientations, or loves. The citizens of each city love fundamentally different things—the earthly city’s citizens are driven by self-love, while those of the heavenly city prioritize love for God above all else.1 This distinction between the two loves lies at the heart of Augustine’s broader understanding of human duality, which posits that individuals are torn between these two opposing forces. In the present article, we explore the complex interplay between Augustine’s doctrine of the two cities and his understanding of human duality. By examining the connection between these two concepts, we seek to shed light on the nature of the human condition and the role that spirituality plays in it. As we embark on this analysis, we first offer a concise status quaestionis, situating our exploration within the broader context of scholarship on Augustine.

1. Recent Studies on the Two Augustinian Cities and Their Loves

Drawing on the work of eminent scholars H.-I. Marrou and R. Markus, extensive scholarly investigation has been dedicated to illuminating the earthly milieu of the two cities throughout their developmental trajectory, from their inception until the culmination of human history. Central to this inquiry is the term saeculum (secular world, temporal realm)—originally introduced to Augustine research by Marrou—which designates the temporal and cultural environment in which the two cities flourished. In the ensuing decades, Markus’ influential monograph bearing the same title catalyzed scholarly debates about this intriguing subject.2 Apart from the question of whether the saeculum constitutes a neutral arena or is occupied by the ciuitas terrena,3 considerable scholarly attention has been devoted to the relationship between the saeculum and the ciuitas peregrina (pilgrim city), the terrestrial component of the city of God.4 Because most studies have underscored the eschatological separation of the ciuitas Dei from the ciuitas terrena, the dynamics of transformation and the process of transition from ciuitas terrena to ciuitas Dei have been insufficiently explored. Recently, however, J. K. Lee has comprehensively examined this dynamic of transformation, first in Augustine’s Enarrationes in Psalmos (Enarrations/Sermons on the Psalms), and then in De ciuitate Dei.5

Just as an aggregate manifests the qualities and features of its components, the societas or ciuitas (society, community) mirrors the attributes of the individuals comprising it. Indeed, a certain parallelism can be drawn between individual people and Augustine’s ciuitates.6 Within each human person, one may discern the traits of each city.7 The purpose of this article is to probe whether the dual nature of the human person parallels the dichotomy between the ciuitas Dei and the ciuitas terrena, the interplay within the saeculum, and the divisions that cleave the terrena ciuitas. The article examines how the internal struggle between good and evil in human beings, and, by extension, in a society comprising them, serves as a model for the conflict between the ciuitas Dei and the ciuitas terrena. To this end, we investigate how these concepts, as foundational elements of Augustine’s doctrine of the two cities doctrine, are expounded in his earlier writings, and then we explore how these components are articulated in his De ciuitate Dei.

2. The Long Road to the Two Cities in De ciuitate Dei

2.1. De uera religione: The Difference between the Internal and the External Human Being

As a young theologian who had recently abandoned his political aspirations—well before the fall of Rome in 410—Augustine of Hippo outlined the trajectory of human life in terms of the external and internal human being in his treatise On True Religion.8 The external human being is driven by a desire for happiness in the earthly city, which is subject to the successive ages of the body, while the internal human being is oriented towards the unchanging abundance of the highest wisdom. The transformation towards wisdom occurs gradually, in accordance with the spiritual ages, as the inner human being grows and learns to subordinate temporal needs.9 According to Augustine, the emergence of two distinct types of human behavior is a consequence of the fall. This duality not only concerns the observable differences that separate people from each other, but it also extends to the internal struggles of each person, as the old human being battles against the new human being. Augustine believed that, as a result of original sin, humanity began its journey by succumbing to carnal desire.10 Nevertheless, he also argues that this failure need not be the end of the story. There are those who embrace the lawlessness of the old human being, and there are others who, through spiritual growth and the attainment of wisdom, gradually overcome the influence of the old human being, despite beginning life as external beings. This process of renewal, which is only complete after physical death, is available to all.11

2.2. De catechizandis rudibus: Two Cities, Mixed in Body, Separated in Soul

Especially in his De catechizandis rudibus (On Instructing the Uninstructed), Augustine the youthful bishop characterizes these two groups of individuals as distinct societies, one a society of the unrighteous and the other a society of the saints.12 Because the former is animated by pride and avarice, referring to its members as a societas may appear incongruous, given their ceaseless struggle for preeminence in worldly affairs. Nevertheless, they are bound together by shared modes of behavior and merit.13 The cohesion that characterizes the second societas is of an entirely different nature. Rather than seeking personal glory, its members humbly strive to glorify God. Their focus is not on earthly matters, but on attaining God’s eternal blessing through pious devotion (pietas).14

Although Augustine refers to these two communities as Babylon and Jerusalem, his intent is not to provide an account of these cities’ historical experience. Rather, the promised land, whose capital is Jerusalem, also known as the city of God or the spiritual kingdom, is a picture of the ultimate kingdom in which Christ reigns over all.15 The name ‘Babylon’ signifies confusio, and Israel’s Babylonian captivity symbolizes the state of the societas sanctorum (community of the saints) amidst the societas iniquorum (community of the unrighteous), which is not yet condemned. Accordingly, the saints are obligated to pray for the unrighteous and are subordinate to the king of this present world age.16 The exile in Babylon is, thus, an image or representation (figura, imago) of the Church as a pilgrim on Earth who must make the most of temporal peace while traveling to the final destination.17

2.3. Enarrationes in Psalmos: The Opposition between Babylon and Jerusalem as an Externalization of the Conflict within the Individual

In his homilies on the Psalms, Augustine explores the symbolism of the opposition between the two biblical cities, Babylon and Jerusalem.18 Babylon represents the transitory world. Jerusalem, a shadow of the eternal Zion, will, after seven periods, culminate in the homeland of God’s eternity.19 Augustine also draws a parallel between the biblical story of Cain and Abel on the one hand and the two cities, the ciuitas terrena and the ciuitas Dei, on the other.20 Cain, who sought a fixed and permanent abode on Earth and placed all his hope in earthly things, represents those who prioritize temporal desires over spiritual goods. According to Augustine, the difference between the two cities can be traced back to the fall of humankind, and is evidenced in the separation of those who savor earthly things from those who savor heavenly things.21 By birth, all are citizens of Babylon, heirs to Adam’s sin and inheritors of iniquity, which weighs them down and ultimately delivers them to death (cf. Rom. 5:19); consequently, from birth, people belong not to Jerusalem, but to the old city.22 However, one can leave the latter by aspiring goodness, by shedding the old self and putting on the new self.23 Born into darkness, humankind must now become light (cf. Eph. 5:8); each person must put off the old self and put on the new (cf. Col. 3:9–10). In this way, the bad habits of the earthly city are replaced, and the foundation of the good city is established.24

Augustine believes that the conflict between the two cities externalizes the conflict within each person. Everyone is internally subject to the conflict between the cities of Babylon and Jerusalem,25 and which city one belongs to depends on one’s love. Babylon represents love of the world, while Jerusalem represents love of God. In his pastoral ministry, if people are uncertain about the city to which they belong, Augustine encourages them to examine their love. If anyone is found to be a citizen of Babylon, yet wishes to leave it behind, that person must eradicate sinful desires and cultivate a love for God. Conversely, those who identify as citizens of Jerusalem must endure the trials of earthly life and await the freedom of the eternal city.26 This hope constitutes a beginning of liberation, although a redeemed person remains captive throughout earthly life. Augustine even heightens this tension by stating that many of Jerusalem’s citizens are enslaved by the corruption of lust, which makes them still citizens of Babylon.27 Because lust persists in the mortal body, all of history takes on the appearance of a pilgrimage in which the earthly city is not condemned outright, but rather assigned the subservient role of facilitating conversion.28

In view of its profound symbolic significance, the term ciuitas is translated as ‘city’, not in reference to a specific historical or political city, but to a community of people who are distinguished mainly by their shared purpose.29 ‘City’, then, refers to a conceptual community—not to an institution such as the state or to a sacramental community such as the visible Church, but rather to a spiritual and moral community. This city encompasses angels and all those predestined by God’s grace, as well as the opposing community of fallen angels and the damned, who dwell in the city of the devil (ciuitas diaboli). In that city, people live not according to God, but according to their own desires, and earthly happiness is the ultimate goal of life.30

Augustine employs the historical cities of Jebus and Babylon as symbols of sin’s consequences, thereby placing those cities in a distinct temporal order. The earthly city, which comes into existence before the heavenly city, is not to be considered superior, despite its temporal priority.31 Augustine acknowledges that the city of Cain, representing the earthly city, predates the city of Abel, which represents the heavenly city. Nevertheless, he argues that despite this temporal priority, the earthly city is inferior in dignity to the heavenly city. This temporal hierarchy is echoed in Paul’s statement that the physical or animal nature is antecedent to the spiritual nature (cf. 1 Cor. 15:46). Thus, the temporal and historical precedence of the earthly city does not diminish the spiritual superiority of the heavenly city.32 Following Psalm 26 verse 10, Augustine notes that the carnal precedes the spiritual. Humans are born of carnal parents who are themselves descendants of Adam and Eve. In addition to these parents, there are other parents: the father according to the world is the devil, and the mother is Babylon, whose lost children extend from east to west. The earthly city of Babylon is humanity’s first mother, from whom her children must depart now that the signs of decay and aging are apparent. Instead, they must turn to their new mother, the heavenly Jerusalem, and to God, their true father.33

The priority of Babylon in Augustine’s thought is implicit, as he sees the city of the wicked through the dual lenses of God’s wrath and God’s mercy towards those who know him. Augustine argues that the city of the wicked is transformed by God’s mercy into the city of the pious, as all nations, upon knowing God, renounce Babylon and become part of Jerusalem. In this transformation, the daughter of the ancient city rebels against her mother and joins the queen to whom the Most High has declared “forget thy people, thy father’s house for the Most High longs for thy beauty” (Ps. 44:11, 21). Augustine highlights the inescapable fact that Adam’s heirs cannot break free from their carnal parenthood and achieve their destiny on their own. It is not by human effort that the new mother, Zion, is established, but only by God, who justifies the wicked. As God creates the mother from whom humanity is born, so too does God establish the city in which humanity is reborn.34 In Augustine’s theological framework, people are burdened with sin, and their conversion is a return to their true nature. This return is not a reward for good deeds, but follows the forgiveness of sins, which can only be granted by God’s grace.35 The penalty of sin serves as a reminder that conversion is not acquired by merit, and the prideful self-attribution of merit nullifies the grace of justification. As darkness must give way to light (cf. Eph. 5:8) and the old self must be replaced by the new (cf. Col. 3:9–10), conversion entails shedding the old habits of the earthly city and adopting new ones founded on the heavenly city.36

As previously mentioned, Augustine likens Israel’s captivity to a state of confusion—a sign of humanity’s mixed nature. Despite the exhortation to turn towards Zion during this period of confusion, people continue to live in a state of tension, not only as members of each community, but also in the desires and affections of their own hearts. This tension results in a mingling of the two cities, a concept that is neither identical to confusio as such, nor completely foreign to the confusion of Babylon. According to Augustine, as long as people live and move in their mortal bodies, they will continue to seek out temporary pleasures and be driven by lust, thus creating a shared bodily experience. Although he argues that people must withdraw from this shared experience, they cannot completely escape it. He represents this paradox by suggesting that each person is born into a state of confusion created by desire, only to be rescued from that state by caritas (love). Love does not entirely remove people from confusion, but rather distinguishes them from it, as they leave Babylon only in the heart and in a hidden way. This departure from the confusion of Babylon is not physical, as no one can escape the necessities of the body.

In support of this paradox, Augustine cites the Pauline verse 2 Cor. 10:3, stating that some, though walking in flesh, do not contend according to the flesh. He argues that such people walk in the city of Babylon, but, through their longing, are already in the city of Jerusalem, to which they anchor themselves in hope. Therefore, the winds and storms that shake the ship of their pilgrimage do not much bother them, since they are already anchored in the city of hope.37 As the bishop of a port city, Augustine was apt to conceive of human desires as a sea whose waves could be invigorating and even tumultuous, and he recognized that these desires were stirred up by the confusion of the world’s time. This understanding aligns with the confusio of the animal body, wherein wicked desires are spawned until the end of the saeculum and must be excised before that body can gain strength.38 When Augustine references the permixtio corporalis (corporeal mixture) of each city, according to which only the affectus cordis (affections/emotions of the heart) have the potential to depart from Babylon, it is important to recognize that this mingling is primarily due to the confusio within the corpus, whether on an individual or collective level.39

Augustine believes that the permixtio corporalis of either city can be deduced from humanity’s inherent duality. The bodily mixing or permixtio corporalis does not, however, carry an entirely negative connotation, since bodily desires are not inherently wicked and can be experienced for either good or evil, notwithstanding their hereditary flaws. While it is true that individuals can be drawn into Babylonian confusion, it is equally true that they remain reliant on the collective corpus (body) for the fulfillment of their mortal needs and are therefore inevitably entangled with Babylon. The young priest Augustine recognizes that the degeneration caused by sensual gratification in the individual corpus would also impair the proper functioning of the collective corpus. In his commentary on Psalm 9, he likens the state to a human body. In this analogy, the head of a person is comparable to the king of a state, and limbs and senses to ministers or servants. The evil city would not exist if its people, as semina or elementa (seeds/germs or basic components) of that city, were not wicked, that is, not at the disposal of the diabolus rex (diabolic king). Similar to the human body, the mortal city (ciuitas mortale) is a mortal body (corpus mortale) in which sin reigns. If individuals combat their flaws and quell the stormy clamor of the movements of their soul, the noise of the unrighteous in the ciuitas will likewise come to a complete halt, resulting in perfect peace.40 Augustine does not explicitly refer to the permixtio corporalis of the two cities at this stage, but rather emphasizes the importance of striving towards ultimate peace in the city. He recognizes that the eradication of vice will require an inner battle to be waged within the mortal body, and suggests that this battle may be a precursor to the concept of bodily mingling. Thus, he proposes that while citizens of the earthly city must engage in the struggle against defects, those citizens can also avail themselves of the temporary peace available on Earth, until the mortal body is fully transformed.

2.4. De doctrina christiana: Prudent Use of Earthly Goods and Institutions

The young Augustine was already realistic enough to appreciate the utility of earthly goods and institutions. In his De doctrina christiana (On Christian Doctrine), Augustine passionately advocates for the use of non-Christian culture, including the liberal arts and non-Christian (‘pagan’) sciences.41 He asserts that this cultural heritage rightfully belongs to Christians and draws parallels to the Exodus story, according to which the Israelites were commanded by God to take precious metals and clothing from the Egyptians. These precious metals symbolize God’s institutions, while the clothing represents human institutions, both of which are necessary for society. Augustine acknowledges that certain conditions must be in place for this cultural assimilation to be considered a Christian reversal. One cannot simply take on non-Christian cultural heritage without spiritual transformation and hearing the call of the slaughtered paschal lamb to come to Christ and embrace humility (cf. Matt. 11:28, 30). Furthermore, Augustine recognizes that cultural heritage can pose a danger and must be approached with caution, as emphasized in 1 Corinthians 8:1.42 It is possible to achieve the necessary liberation from pride by using hyssop, which is a modest and mild shrub whose roots possess remarkable strength and depth. Drawing oneself along with hyssop is symbolic of the cross, which has the power to purify individuals of their pride and represents the establishment of caritas, or Christian love. Like a plant, that love roots and stabilizes people.43

The Paschal symbol empowers Christian action and is imbued with the capacity to comprehend the all-encompassing caritas of knowledge. This caritas is the divine love, by which Christ is co-equal with the Father. Their parity grants insight into Christ’s identity as sapientia or divine wisdom, a concept that undoubtedly intersects with the ultimate pax in fine (final/definitive peace).44 A prudent use of temporal peace prior to the end of time requires purification with hyssop, which is accomplished through the completed Passover. This purification ensures that Christians are endowed with edifying love instead of inflated knowledge. Pride (superbia) and humility (humilitas) once again emerge as the regulating forces of the current epoch, in which they govern the utilization (uti) of the Christian inheritance. Recognizing this shared role of pride and humility sheds a novel light on the relationship between contemplation (contemplatio) and action (actio), the city of God (ciuitas Dei)), and earthly society (ciuitas terrena).

2.5. De Genesi ad litteram: Two Forms of Love

Augustine delineates two opposing communities defined by their opposing loves in his Litteral Commentary on the book of Genesis:

One amor (love) is sacred, the other amor impure;

one targets allies, the other excludes them;

one cares for the common good for the sake of the higher society, the other wants to reduce even the common cause to the power of self for the sake of presumptuous domination;

one submitting to God, the other competing;

one is calm, the other is stormy;

one is peaceful, the other riotous;

one prefers the truth to the praise of those who err, the other is fond of any praise whatsoever;

one is friendly, the other is jealous;

one wants for neighbour what he wants for himself, the other wants to subject neighbour to himself;

one leads the neighbour with a view to his interest, the other aims at his own interest.45

The two loves are expressed in the two cities: that of the righteous and of the unrighteous.46 Augustine explains that each city existed first among angels, and then among people. At the present time, the two cities are mixed, but at the last judgment, they will be separated. The final destination is eternal life for the first city, eternal fire for the second.

Although Augustine speaks of two distinct and opposing communities or cities, they are not entirely disconnected from one another. The full separation of these cities will only occur at the last judgment, which marks the end of the temporal mixture of the two worlds (during the saeculum). At the last judgment, one of the cities will be united with the righteous angels and receive eternal life from its king, while the other will be joined with the wicked angels and their king and be consigned to eternal punishment in the fires of hell.47 Augustine’s reasoning allows him to grasp the significance of Cain’s construction of a city where none had existed before, and to elucidate the necessity of the Israelites’ conquest of the Jebusites and subsequent transformation of that city into the new Jerusalem. Initially shrouded in darkness, people are called to become light (cf. Eph. 5:8) and to cast off the old self in order to be clothed with the new self (cf. Col. 3:9–10). The negative ciuitas extends from beginning to end, while the positive city is founded by transforming the bad habits of the earthly city.48

In Augustine’s grand narrative of history, the world (saeculum) created by God becomes divided and intermixed between the forces of good and evil. This duality was caused by the choice of some angels and later by human transgression; after a process of redemption, the duality culminates in a final and radical separation of two cities. These two cities embody the battling loves of the fallen angel and of Christ, who respectively preside over their distinct corporate powers. The bad city is propelled by universal greed, animated by the pride in which angels and mortals partake. While each city engages with material goods, only the bad city deals with them in a privatized and possessive manner, motivated by their bodily needs. In contrast, the good city engages with material goods solely through caritas, which rejects the desire for personal gain. While the good angels have no dealings with earthly goods, people share in the general spiritual communion brought about by caritas through the proper use of these goods. Thus, the two cities are corporally interconnected. Augustine’s narrative emphasizes the significance of the bodily realm in this struggle, for the love of money and material possessions can be traced to the human body and its needs. Through proper guidance and discipline, the bodily realm can be transformed into an instrument for good, and the worldly city can be remade into the city of God.49

It is of paramount importance to observe that the differentiation repeatedly observed in the contentious relationship between the two cities is not an unanticipated struggle between good and evil. Similarly, the fall is not predetermined, even though everything unfolds under the incomprehensible providence of God. This enigmatic concept is a critical tenet in Augustine’s philosophy; he postulates that evil exists outside of God, yet never transpires without God’s permission. To suggest otherwise would introduce an additional power besides God, thereby negating divine omnipotence. Nonetheless, divine power does not constrain the freedom of choice between good and evil, a choice that God foresees and regulates, thereby serving as the ultimate arbiter between the two cities. Their intermingling in the present world will culminate in a final judgment, which will end the saeculum, just as auaritia (greed) and caritas (Christian love) marked the inception of our world history. This separation will be accomplished solely through God’s judgment, underscoring divine dominion over our world era.50

3. De ciuitate Dei

Augustine’s thinking about how the two cities and their loves are reflected in the internal duality of each person receives its fullest elaboration in De ciuitate Dei.

3.1. Defining the Two Cities

In this massive treatise, Augustine stresses the stark contrast between self-love in the earthly city and love for God in the city of God. In ciu. 14.28, a textual shift is observed: the thematic focus on the dichotomy between private and common interests, familiar from Augustine’s earlier works, is supplanted by an emphasis on self-love, specifically the pursuit of renown, which inevitably entails the exertion of dominion over others:

“Two cities, then, have been created by two loves: that is, the earthly by love of self extending even to contempt of God, and the heavenly by love of God extending to contempt of self. The one, therefore, glories in itself, the other in the Lord; the one seeks glory from men, the other finds its highest glory in God, the Witness of our conscience. The one lifts up its head in its own glory; the other says to its God, ‘Thou art my glory, and the lifter up of mine head’ [Ps. 3:3]. In the Earthly City, princes are as much mastered by the lust for mastery as the nations which they subdue are by them; in the Heavenly, all serve one another in charity, rulers by their counsel and subjects by their obedience. The one city loves its own strength as displayed in its mighty men; the other says to its God ‘I will love Thee, O Lord, my strength’ [Ps. 18:1]. Thus, in the Earthly City, its wise men, who live according to man, have pursued the goods of the body or of their own mind, or both. Some of them who were able to know God glorified Him not as God, neither were thankful, but became vain in their imagination, and their foolish heart was darkened.”51

In the earthly city, rulers and subordinates indulge in perishable images and serve creation rather than the Creator. Only in a society where God is all in all can the true and imperishable God yield benefits.52 Augustine’s conception of earthly existence involves a binary division of human societies into two exclusive categories: the ciuitas Dei and the terrena ciuitas. As was true in earlier works, the inhabitants of the two cities are not limited to the mortal beings who dwell upon the Earth; rather, the cities encompass the celestial and terrestrial spheres. Included among the immortal beings are the angels, comprising the benevolent denizens of heaven and the malevolent entities who have renounced their celestial abode. The good angels and mortal lovers of God inhabit a single ciuitas, just as there is but one city for the evil angels and mortal lovers of self. Hence, we have two cities and not four.53 The good angels are members of God’s city, and the mortals who love God and reside here on Earth are merely a constituent part of that city. In due course, after completing their earthly pilgrimage, these mortals will join forces with the immortal angels, for the outpouring of God’s caritas by his Spirit pertains not only to holy people, but also to holy angels. It is a good thing for both to adhere to God (cf. Ps. 72:28), and this goodness is common to both. Together they possess, in God and amongst themselves, a sacred societas and thus represent a single city of God—the very city that constitutes a living sacrifice and holy temple for God.54 Augustine argues that when human yearning for unity is intertwined with God’s unity, a fundamentally different type of community emerges: one in which communality takes on a distinct character. In this new community, peace is no longer a means of arranging and fulfilling desires within the confines of mortal existence (mortalitas), but instead is grounded in caritas, which allows for equal participation in an eternal commonwealth, thereby obviating the need for power struggles.55

Since the separation between light and dark (Gen. 1:3f.), the wicked angels have abandoned the one and only source of enjoyment and instead are driven by their inflaming pride (typhus). Rather than the ardent fire of pure love, they are left with only the smoke of impure love, or self-exaltation. They have relinquished the tranquility of the heavenly spheres for disruptive turmoil, and the radiance of piety for the shadows of carnal desire. These angels yearn for revenge and pride, seeking to inflict punishment and subjugation rather than serving God’s goodness and administering justice only at his command.56 Like the wicked angels, mortals tend towards darkness whenever they forsake the common and public domain (communis et publicus uniuersus) in favor of the private and individual sphere (pars priuata et propria). This tendency towards privatization entails not only a specific greed (auaritia specialis), such as the love of money (amor pecuniae), but also a general greed (auaritia generalis), namely, pride (superbia). Since Adam, people have repeated the original sin time and again, succumbing to envy, which ensnares them in the privatization that is sensual pleasure.57

3.2. Earthly Goods

In their conduct, the constituents of the ciuitas Dei and the terrena ciuitas are governed by their respective interior dispositions towards property, power, fame, and pleasure. A proper disposition within the heavenly city is marked by a devotion to love, harmony, and the communal use of resources. Conversely, a defective disposition within the earthly city is characterized by lordliness, internal discord, and the individualistic exploitation of resources. While the proper disposition is endowed with boundless spiritual riches, the defective disposition is fraught with competition and strife over scarce material resources. True satisfaction, however, can only be found in that which is indivisible and uniquely capable of providing unity, and the enjoyment of that unity guarantees eternal peace for the community. The true enjoyment that fulfills and guarantees eternal peace is only possible in the societas of the highest order,58 where the spiritual body supplants the animal body, thereby transcending deficiency and mortal limitations, when the body in all its parts will be subject to the will.59

This desired state of enjoyment leads Augustine to the famous declaration that God and human beings in God are the only objects of true enjoyment, and all other realities are only to be used (uti) in light of this enjoyment (frui).60 An alternative formulation could be that, according to Augustine, the pursuit of unity, when tethered to God’s own unity, leads to the emergence of a different kind of societas—one imbued with caritas, wherein all can partake equally of the eternal and indivisible common property, rendering power struggles and violence moot.61

Augustine cautions that the earthly city, if it prioritizes earthly goods over the superior goods of the heavenly city, becomes a snare that amplifies misery.62 Earthly goods, which are inherently mutable and divisible, almost inevitably engender conflict and warfare when people regard them as ultimate sources of satisfaction. The earthly city is thus often divided against itself by strife, war, and struggle. Triumphs attained through military conquest, while initially exhilarating, are inherently fleeting and only transitory. They are, in a word, mortal (mortalis). In certain instances, these victories may even prove to be fatal (mortifer), insofar as they engender arrogance in the victors. The victors’ hubris blinds them to the precariousness of their accomplishments and precipitates further conflict and strife, perpetuating the cycle of warfare.63

Hence, in earthly society, each individual is inextricably linked to the faithful citizens of the ciuitas Dei and to the faithless members of the terrena ciuitas; together, the faithful citizens and faithless members possess a stake in the common good. A shared use of resources cannot be deemed inconsequential or morally neutral, since the ultimate goal of such use (usus) determines whether one is inclined to dwell in the abode of those whose aspirations are confined to the earthly realm (terrena), or in the abode of those who perceive earthly goods as no more than a means of easing the burden of their mortal bodies.64

3.3. Earthly Peace

Earthly peace is based on submission to a victor. The fragility of this submission notwithstanding, victory is directed towards the attainment of peace, which, paradoxically, remains the ultimate objective of war. While the contours of such peace may be varied, no party engages in hostilities without an end in view, and even if the warring entity disrupts an existing state of tranquility, that entity is motivated by the desire for another form of peace in which its aspirations can be realized.65 In contemplating the interplay between war and peace, Augustine endeavors to shield humanity from the caprices of human wrath and to spare the divine from appearing passive and powerless. For this purpose, Augustine invokes the well-established notion that peace (pax) imbues all facets of terrestrial existence, endowing them with a harmonious and cohesive internal and external framework, and conferring upon each constituent the tranquility of structure.66 Augustine maintains that a fundamental tranquility permeates society, even when social structures are established in a corrupt manner. This peace, which belongs to the very fabric of nature, is indispensable to nature’s unity. In the absence of peace, nature would be rendered incomplete and unrecognizable.67

In this respect,68 Augustine does not categorically dismiss temporal peace (pax temporalis) as belonging to the city of the devil (ciuitas diaboli), but rather attributes the vice of pride to the peace of the earthly city, rendering that peace a reprehensible discontent (Van Oort 1991). Despite its inadequacy and dark side, Augustine refrains from declaring that earthly peace is worthless or bad; instead, he recognizes a deficiency in something that is inherently good. The human race strives for this peace, just as it strives for happiness, despite humanity’s flawed nature after the fall. The earthly city may rightly be called a societas that is organized around the pursuit of a subordinate good. Augustine even acknowledges that the earthly city can itself be good if it attends to its interests.69

Although the earthly city, through its own peace, remains a durable societas, that societas is ultimately less than eternal and will cease to be a city on the day of the final judgment. In the end, the earthly city will know no peace.70 Even now, change and deprivation are common characteristics of the earthly society, unlike the city of God. It is possible that the privatizing movement, which is nearly unique to the earthly city, is a consequence of its transient peace. Augustine suggests this causal connection indirectly, but highlights the provisional and mortal character of the earthly city through repeated contrasts with the heavenly city’s everlasting peace. These contrasts suggest a connection between the transient nature of earthly peace and the privatizing movement that often accompanies it.71

Subtly and surreptitiously, Augustine draws a parallel between a city riven by conflict and a lifeless body. Just as a corpse still manifests an underlying coherence and even in a state of decay helps constitute other forms of unity according to the laws of the divine order, so too does the earthly city’s transient and mutable nature remain within the ambit of the Creator’s providence, serving as a possible substrate for other modes of unity.72 Although Augustine does make this connection explicit, he eschews any mention of greed (auaritia), which fosters a solipsistic peace that excludes others. Within the sensual unity of this self-absorbed order, there is no room for other people, except for those who are willing to subsume themselves into the sensual unification of the prideful and to abide by their dictates. Augustine does touch upon the general desire for unity that impels humanity to adhere to the laws of nature and maintain peace within earthly communities, provided that other people acquiesce to the sensual satisfaction of humanity’s perception of unity, leading to conflict with those who refuse to submit. Augustine posits that the privatization inherent in sensual pleasure is incompatible with human community, and that pride acts as a malignant growth that sows the seeds of war.73 Nevertheless, Augustine contends that every war, including a just war, bears the imprint of a peace, albeit a distorted one. The cause of this perversion is the haughty human being, who apes God, rejecting equality with peers under the aegis of the divine and endeavoring to appropriate God’s glory.74

In Augustine’s view, perversion is not rooted in rejecting the imitation of God, in whose image humanity was made. Rather, Augustine argues that as God’s righteous offspring, humans are meant to exercise authority over the world. Perversion occurs when individuals mistakenly believe that the unity and glory of God can be translated into a form of power that can be seized and used as a tool of violence. Any attempt to seize this power results in a distortion of glory, transforming it into a harmful instrument rather than a force for good.75

3.4. Heavenly Peace

Although the peace of Babylon is shared by the virtuous and the wicked, the peace of the heavenly city is peculiar (proprius) to its own inhabitants. In fact, the peace of the earthly city provides, rather than joy and happiness, only consolation for misery. Thus, the happiness that we currently possess through faith will someday be ours indeed. Even iustitia (justice), which is pursued for the sake of the true good at which it aims, must be understood as the forgiveness of sins rather than as perfection, which thus cannot be attained by an individual’s own strength. Even the virtuous and righteous, who must contend in an orderly way with the flaws to which they must submit, are denied full peace (plena pax). Only in the final peace will our nature be irrevocably healed by immortality (immortalitas) and become imperishable and free from any defect.76

3.5. Two Cities Mingled in Earthly Time and Space: Corpus Permixtum

Augustine draws from Scripture yet another interpretation of the confusion (confusio) present in the city of the wicked. Here, he emphasizes not merely the temporal fragmentation that results from scattering, but rather retribution for sin, namely, the confusion of tongues, or the division of languages, which partitions humanity on account of its wicked pride. The interaction between temporal dispersion and linguistic confusion exacerbates the discord of confusio, underscoring the punitive dimension of time, which, together with language, ought to have facilitated harmony.77

The ambivalence within humans mirrors the entanglement of the two cities. Augustine presents a complex view of the human body as a flawed entity, capable of slipping into evil, and as a created good with the capacity to choose the good. This duality of the body leads him to elaborate on the intertwining (permixtio) or connection (coniunctio) of the two mixed cities (ciuitates perplexae)—the earthly city and the city of God.78 While the intertwining in the secular realm is primarily due to our embodiment, both individually and collectively, the spiritual corpus is equally responsible for the intertwining in which we are included by the grace of reversal.79 This blending of the two corporate magnitudes is a grand reflection of the duality within the individual and does not allow for an intermediate position, which would belong neither to the earthly city nor to the city of God. To propose the existence of an intermediate place between the intertwined cities would not only negate the saeculum’s ultimate orientation towards God, but would also threaten the duality inherent in human nature. Such a notion of an intermediate space is therefore incompatible with the theological framework laid out by Augustine. It is crucial to acknowledge that the ambiguity of the commixtio (mixture) will continue until history’s end, and that Augustine’s call for a virtuous use of temporal peace plays a pivotal role in navigating the complex interweaving of the two cities. To embrace an intermediate position would be to deny the essential tension in human experience and would prevent one from fully embracing the divine vision that guides humankind towards its ultimate end.80

3.6. Conflict between the Earthly City and the City of God

Earthly time and space constitute the battleground for the conflict between the earthly city and the city of God on Earth. To expand upon the previous discussion, it is important to acknowledge that this battle should not be viewed solely as an internal struggle, that is, a struggle within the earthly city, but also as a battle between the earthly city and the city of God. The city of God maintains control over the earthly city with regard to religious laws, and as a result, a battle between these two cities often ensues.81 The stakes of this battle are markedly different than those of an internal struggle for earthly peace. While Babylon and Rome may have similar foundations, there is a profound difference between the fratricide of Cain and that of Romulus. The two brothers of Rome were citizens of the same earthly city, divided against one another for the sake of power. By contrast, Cain and Abel were not equals in their desire for possession; the result was not a struggle within a single city, but rather a battle between the city of God and the earthly city.82 Furthermore, it has been demonstrated that the conflict between Jerusalem and Babylon cannot be apprehended solely as a dichotomy between the virtuous and the vicious, since the physical blending (permixtio corpore) due to shared mortality (communis mortalitas) precludes too facile a division between the righteous and the wicked in this life.

The ambivalence in the human heart serves as a model for the struggle between the ciuitas Dei and the terrena ciuitas, and the fusion and interweaving of the two cities hints at the ambivalence intrinsic to every human heart.83 Undoubtedly, all human beings commence their journey possessing the animality of greed, and until the final judgment’s distinctio (distinction/differentiation) is accomplished, the conflict between the animal and the spiritual persists within us. Inspired by the earthly city at war with itself, Augustine describes this inner personal battle in intriguing ways, using terms such as conflict, struggle, resistance, pressure, command, and victory.84 As in the earthly city, where peace remains vulnerable and unsettled because the adversary is never wholly subdued, heavenly peace cannot be expected in this mortal life.85 Although hidden desires can be managed, they are never wholly conquered, and the struggle will ultimately be resolved only in the spiritual body (corpus spiritale).86 Moreover, the fight against others, in the sense that we, as citizens of Jerusalem, contend with Babylon, persists and will cease only at the end of time (in fine temporum), when the dead and decaying body of the earthly city is transformed into the heavenly Jerusalem.

Augustine asserts that in this peace, none of us will live in conflict with ourselves or others.87 Eventually, caritas will triumph over greed, and society will become imperishable and ordered towards the common good. No one will desire to take away from others, but will, conversely, aspire to share undividedly, since there will be an expansion rather than a contraction of goods.88 Meanwhile, world time (saeculum) remains the field of battle between the two communities, and Cain’s fratricide of Abel, a citizen of the eternal city and a stranger on Earth, is an archetypal instance of this history.89 Against enslavement to greed stands Isaac, a son of grace, an inhabitant of the free city, and an ally of eternal peace, which has no room for the will to appropriate and privatize, but welcomes the heart that delights in the common and imperishable good and makes one heart out of many hearts. This peace is perfect unity achieved through the obedience of caritas.90 Thus, the fratricide of Remus by Romulus serves as a premonition of the relations within the earthly city (ciuitas terrena), and it is remarkable how similarly Augustine characterizes the wicked angels’ conduct.

3.7. Cooperation between the Earthly City and the City of God

As we already observed in De doctrina christiana, Augustine advocates the adoption and use of the earthly city’s institutions by the citizens of the ciuitas Dei: for the sake of earthly peace, the city of God on Earth also makes use of earthly institutions.91 To delve into the intricate and at times enigmatic relationship between the earthly city (ciuitas terrena), in which we are but exiles or prisoners, and the heavenly city (ciuitas Dei) that awaits us, is a task beyond our present purview. It suffices to note that, following the fall, the original felicity has been forfeited, and ever since, people seek gratification in transient things. Yet those who work diligently and without conceit towards this earthly city, God will not surrender to Babylon; instead, God will reveal to them the other city, which renders Babylon a mere trifle, albeit a trial of their faithfulness, to see whether they are serving the greater good.92

Augustine’s profound reflections on the matter of earthly goods can be found in the nineteenth book of his De ciuitate Dei, in which he expounds the necessity of mortal life. He posits that, due to the shared experience of mortality, earthly peace is of utmost importance not only to temporal society, but also to celestial society. Thus, he asserts that concord between the two cities on matters pertaining to mortality can be achieved without difficulty.93 His call for a good use of the Babylonian earthly peace, which is, after all, common (communis) to good and bad alike, is therefore unsurprising. However, if we do not use this temporary peace for good, then eternal peace will not be our portion at the end of time.94

Although mortality (mortalitas) is common to both cities, immortality (immortalitas) is not, thereby precluding the establishment of universal laws of religion (communes leges religionis).95 Such common laws would require the professed iustitia to be identical, which would inevitably result in the earthly city becoming a fundamentally distinct community, thereby calling into question the very notion of ‘earthly’ itself.96 In its foundation on an everlasting peace that produces happiness for all, with God as the common element uniting all people, the city of God is unique.97

4. Citizen of Two Cities—The Inherent Duality of Love

In our concluding remarks, we summarize the development of Augustine’s thinking about the intrinsic link between the two cities and the inherent duality of human love, and then we offer a thematic synthesis.

Augustine’s intellectual evolution is characterized by a shift in attention towards previously overlooked elements, reflecting the changing context of his thought. This evolution can be traced through various works. Augustine’s early work, De uera religione, dating back to 390, before his priestly ordination, reflects his focus on the internal and external aspects of humanity, which aligns with Neo-Platonist philosophy. In De catechizandis rudibus, written in 404, Augustine introduces the concept of the two cities, highlighting the distinction between Christianity and ‘paganism’, while also drawing on the dual cities concept of the Donatist Tyconius. Enarrationes in Psalmos, a pastoral work consisting of sermons on the psalms, is difficult to date precisely, but covers a considerable period. It touches on the themes of Jerusalem and the heavenly Jerusalem, and the proper disposition of the individual towards God and this heavenly city. Books 1 to 3 of De doctrina christiana, written in Augustine’s early years as a bishop around 396–397, delve into the appropriate Christian approach to worldly possessions among other topics. In De Genesi ad litteram, composed between 414 and 415, Augustine introduces the concept of love as a distinguishing factor between the two cities.

The early books of De ciuitate Dei, apart from their apologetic aspect in defense against the pagans after the fall of Rome in 410, also contain references to the Donatist controversy, including the intermingling of ciuitas Dei and terrena ciuitas. The later books of De ciuitate Dei reflect Augustine’s engagement with the Pelagian controversy, discussing the divine grace that can restore human fallenness due to original sin, manifested in incompatible loves for God and self. Augustine also delves into the origins and ultimate destination of the two cities, exploring the themes introduced earlier in a cohesive manner. In summary, Augustine’s works reflect his evolving ideas and perspectives on various theological concepts, shaped by historical context, philosophical influences, and his own theological inquiries.

Prior to his De ciuitate Dei, Augustine had already lain the groundwork for his doctrine of the two cities. He began with a dualistic view of humanity that distinguished between the old, external human being with earthly desires and the new, reborn, internal human being oriented towards heaven, as expounded in De uera religione. In De catechizandis rudibus, Augustine divides people into two groups: the righteous and the unrighteous, and assigns to these groups the names of ‘Jerusalem’ and ‘Babylon’, respectively, with ‘Jerusalem’ designating the heavenly city where Christ is king, and ‘Babylon’ designating the city in which the people of Israel lived in exile for seventy years. In Enarrationes in Psalmos, Augustine examines the mixing of these two groups and the relationship between the two cities. This theme is connected with the transformation from a physical person (homo animalis) to a spiritual person (homo spiritalis). Augustine then considers the relationship with God, and distinguishes the two cities and classes of people by their loves, directed either towards God or towards themselves, pridefully wanting to be equal to God, as discussed in De Genesi ad litteram. These foundational concepts serve as the building blocks for Augustine’s mature doctrine of the two cities, which he later expounds in De ciuitate Dei.

Augustine’s doctrine of the two cities divides humanity into two groups based on their orientation towards God and self. The city of God is characterized by love of God, while the earthly city is characterized by self-love and the neglect of God. In De ciuitate Dei, Augustine maintains that humankind is fundamentally good, yet vitiated by the fall, which injured and weakened human nature; consequently, each person must struggle to overcome evil inclinations and be transformed from a physical being into a spiritual one. Within the saeculum, the temporal realm where citizens of both cities coexist, unhappiness originates from human nature’s inclination to evil. Relations within the earthly city are characterized by lordliness and the appropriation of earthly goods, leading to constant conflict and war. Augustine, nevertheless, acknowledges the value of human institutions and society, though they are temporary and only instrumental to the supreme good of ultimate peace and bliss in God. Thus, the duality that Augustine perceives within human nature extends to the saeculum, which is not a neutral third space, but rather is defined by the orientation of its citizens. Therefore, Augustine urges us to respect and take seriously earthly institutions, but also to regard them as created for a temporary purpose, which is to serve citizens of the earthly city. In contrast, ultimate bliss with God is the supreme good, characterized by a perfect unity with God and with each other, a unity that is based on caritas.

In the present study, our analysis has revealed the nuanced presence of duality in Augustine’s thought at various levels. Firstly, we have identified a dualism pertaining to different love-orientations between the ciuitas Dei (the city of God) and the terrena ciuitas (the earthly city). Augustine discusses how these two cities have distinct orientations towards love, with the former focused on love for God and the latter driven by earthly desires. Secondly, we have observed a dualism within the saeculum (the temporal world) itself, which serves as the earthly context for both cities. Augustine elaborates on how the city of God interacts with earthly institutions and goods, urging cooperation for the sake of temporal well-being, while also advocating for prudent distinction in pursuit of heavenly goods. Thirdly, we have identified a dualism within the human person, who is depicted as inherently sinful and inclined towards evil due to original sin, yet also well-created and restored to goodness through divine grace. Augustine highlights the tension between a human being’s fallen nature and his potential for redemption, underscoring the complex interplay of good and evil within human nature. De ciuitate Dei, with its framework encompassing the origin, evolution, and final destination of both cities, serves as a unifying lens that synthesizes these distinct dualisms.

The consequences of original sin showcase the inherent duality within humankind, where humans are fundamentally oriented towards either choosing God or rejecting him, thereby determining their ultimate destiny of either union with God or eternal separation from him. Furthermore, Augustine’s teachings emphasize the need for cooperation and distinction in the earthly context, where both cities and classes of people can collaborate for the betterment of temporal goods, while maintaining a clear differentiation in pursuit of heavenly goods. Augustine highlights that earthly goods can be transient ends in themselves or mere means towards the ultimate end of bliss in God, and this distinction should inform one’s choices and actions in relation to earthly goods. Augustine believes that true peace can be achieved by bringing human striving for unity together with God’s unity, resulting in a societas based on caritas. In summary, our findings in this study elucidate the multifaceted nature of duality in Augustine’s thought, ranging from the distinction in love-orientations between the two cities, to the interplay of good and evil within human nature, and the need for cooperation and distinction in the pursuit of earthly and heavenly goods.