Briefly discuss St. Augustine’s theory of peace.

Augustine on War and Peace

Andrej Zwitter and Michael Hoelzl

A re-reading of Augustine’s theory of war and peace can be fruitfully advanced if we better

understand his comprehensive concept of peace as the harmonic interaction of individuals with each

other, mediated by their relationship with God. After introducing Saint Augustine as peace rather than

just war theorist, we expand on Augustine’s conception of universal peace as laid out in De Civitate

Dei contra Paganos (City of God Against the Pagans, usually simple referred to as Civitas Dei) in its

socio-historical context. Finally we compare Augustine’s theory of universal peace with Kant’s

concept of perpetual peace in his famous and highly influential treatise Zum ewigen Frieden. The

comparison between Augustine and Kant will allow us to see how the vision of a universal peace has

been conceived in theological terms by Augustine and in what ways it has been re-conceptualised in

secular terms by Kant and his vision of a perpetual peace between individuals, between states and

finally perpetual and enduring peace in the world.

St. Augustine (born 354 in Thagaste, today Algeria; died 430 in Hippo Regius, today Algeria) is one

of the four patristic fathers of the Latin Christian Church and from 396 until his death he was Bishop

of Hippo, province of North Africa. Augustine is one of the most influential theologians of all time

and his Civitas Dei (413-26), Confessiones (397-98), De Trinitate (399-414) as well as his studies on

memory and the nature and essence of time have influenced philosophers like Descartes or

Wittgenstein and of course generations of theologians. In short, Augustine’s influence on the

development of Western Philosophy cannot be underestimated. This is also true because Augustine

lived during a period in which Christianity became a universal religion. With Augustine, especially in

Civitas Dei, for the first time a theology for the Empire has been formulated. In addition to his theo-

political ambitions, we find in Augustine some of the most remarkable and honest accounts of a

person’s intimate struggle with the question of what a true belief is and what makes a belief

believable as he elaborates in De Vera Religione.

Augustine is heralded to be the founding father of just war theory. Civitas Dei is Augustine’s only

work that deals with the customs of war and the conditions of peace. However, in Civitas Dei, which

can be seen as a Summa of his theological and philosophical ideas, Augustine surprisingly treats the

topic of just war only marginally. In fact, the context and the purpose of Civitas Dei is a different one.

The book itself is a defense of the City of God (civitas dei) and its role vis-à-vis the City of Man

(civitas terrena). Both cities stand as allegories for the earthly and heavenly realm coexisting in






parallel with the church as mediator between the two. Augustine’s understanding of the Church, as an

earthly community of believers being on a pilgrimage towards the heavenly city of God, has often

been underestimated.

Without this dual construction of the Church as being both, terrestrial and heavenly in the making,

Augustine’s Civitas Dei is and was prey to a dualistic, and finally Manichaean understanding of

spirituality and temporality. With this ecclesiological pre-text in mind one has to read his analysis of

just war theory. Providing a theory of just war (bellum justum) is not Augustine’s main aim. In terms

of the person, Augustine is a converted Christian and bishop writing about his theological theory of

the two cities.

To strip, however, Augustine’s thoughts and brief comments on just war from the context of the book,

namely the theological doctrine, would gravely misrepresent Augustine’s ideas. Let us, therefore,

divide Civitas Dei into the traditional separation of just war doctrine into ius ad bellum (the right to

war) and ius in bello (the law in war), and let us add the rather new concept of the ius post bellum (the

law after war). And within this threefold categorization we will try to highlight the theological and

moral contexts (these two cannot be separated in Augustine’s thought) to which they belong.

Ius ad Bellum. Augustine gives hardly any thought to the right to war. In book II chapter 17, he states

that war has to first be declared and that the denial of the Sabines (an italic tribe that lost its

independence to Rome) to give their women to the Romans did not justify the act of war. ‘(T)he wise

man will wage just wars’, as Augustine states in book XIX, chapter 7, but he will still grief over the

great evils and cruelties of war, and thus one can assume he will aim to keep them to a minimum.

Wisdom is one of the classic virtues in the moral theory that lasted until the enlightenment. It is the

key virtue (prudentia) that guides the conduct of all other virtues. Virtues are either gained through

practicing virtuous behavior until it becomes a habit to act virtuously, or virtues that can be inspired.

And this inspiration is an act of God, more specifically an act of the Holy Spirit. Thus, so inspired or

habitually acting in accordance with natural law, the wise man cannot do other than wage a just war.

Furthermore, a just war can only be waged against sin (book 19, chapter 15). And every victory, also

those gained by wicked men, is derived by God’s judgment of whether the vanquished to be humbled

or for removing or for punishing their sins. In other words, the cause of war can only be the sin of

man. Its purpose is the extension of the virtuous kingdom as necessary consequence if the alternative

would be that empires ruled by wicked man would otherwise threaten the peace. He thus allows for

just wars as a response to a wrong (causa iusta) and which leads to extending one’s empire, under the

condition that this empire leads to a stable peace (intentio recta).






Augustine, however, states that a peace based on neighborly concord between many small kingdoms

would best resemble the city of God, which would be most conducive to a lasting peace (book IV,

chapter 15). As we will see later on in Kant’s conception of perpetual peace (specifically in the

second definitive article) there is a striking resemblance between Augustine’s divine pluralism and

Kant’s view of a federal community of states when he outlines the conditions of the possibility for

international law (ius gentium).

Ius in Bello. The first few chapters of Civitas Dei deal with the customs of war. However, differently

than one might expect, Augustine does not lay down the rules that would apply during war. Rather,

what becomes immediately clear, Augustine’s argument is that the customs of war knows no limits,

but cruelty and slaughter constitute the customs in the conduct of war. The sacking of Troy (book I,

chapters 2-4) serves Augustine as a prime example that the status of kingship did not protected

Priamos, and neither did his fleeing into the sanctuary of the temple protect him from being

slaughtered by the Greeks. In chapter 5, Augustine refers to Caesar’s own words in the senate to

illustrate that nobody should view the customs of war during this period as anything but cruel:

Even Cæsar himself gives us positive testimony regarding this custom; for, in his deliverance in the senate about

the conspirators, he says (as Sallust, a historian of distinguished veracity, writes ) that virgins and boys are

violated, children torn from the embrace of their parents, matrons subjected to whatever should be the pleasure of

the conquerors, temples and houses plundered, slaughter and burning rife; in fine, all things filled with arms,

corpses, blood, and wailing.

In contrast to these customs of war very much as an exception to the norm, Augustine points out

(book I, chapter 6) that the Romans were famed for behaving particularly well mannered in war. They

were claimed to spare the vanquished, to forgive injury rather than to seek revenge, and to exempt

temples from plunder and spare those who were seeking refuge there. Augustine, however, illustrates

that the reality is farther from the fame. Particularly Marcus Aurelius, which Augustine describes as a

‘poster child’ in war, serves as example that despite his commands that no free people should be slain

the city of Syracuse was sacked according to the customs of war. The treatment of the customs of war

serves Augustine not only to illustrate that war is cruel, but also that Christianity exerts a civilizing

effect on war through inspiring virtues and that Christ’s power even inspires the barbarians.

Ius Post Bellum. A victory in a just war leads to peace and in the case of Augustine’s theory should

lead to universal peace. The concept of universal peace is much more complex than, for example, the

contemporary concept of ‘positive peace’ as advocated by Johann Galtung. Galtung understands

‘positive peace’, in a way reminding of Thomas Hobbes, as absence of structural and cultural violence

opposed to ‘negative peace’ in the sense of absence of direct violence only. In Leviathan (book II, ch.

XIII), Hobbes famously states:






For as the nature of foul weather lieth not in a shower or two of rain, but in an inclination thereto of many days

together: so the nature of war consisteth not in actual fighting, but in the known disposition thereto during all the

time there is no assurance to the contrary. All other time is peace.

It is in regard to peace that the fundamentally theological dimension of Augustine’s treatment of just

war becomes completely evident (book 19, chapter 13):

The peace of body and soul is the well-ordered and harmonious life and health of the living creature. Peace

between man and God is the well-ordered obedience of faith to eternal law. Peace between man and man is well-

ordered concord. Domestic peace is the well-ordered concord between those of the family who rule and those who

obey. Civil peace is a similar concord among the citizens. The peace of the celestial city is the perfectly ordered

and harmonious enjoyment of God, and of one another in God. The peace of all things is the tranquillity of order.

(…)As, then, there may be life without pain, while there cannot be pain without some kind of life, so there may be

peace without war, but there cannot be war without some kind of peace, because war supposes the existence of

some natures to wage it, and these natures cannot exist without peace of one kind or other.

To understand the complexity of Augustine’s thought, we need to take a look at the logic of virtue

ethics vis-a-vis politics. In contrast to our contemporary understanding of the difference between

politics and morals, such an understanding was foreign to the classic virtue ethicists. For Aristotle,

ethics was the art of living well as an individual and politics the art of living well of a society and the

art of ruling well of this society. The key concept is eudaimonia – that is flourishing and wellbeing.

With pax universalis Augustine introduces reinterpretation of eudaimonia. Universal peace is thus not

only to be understood as a mono-dimensional peace, as a common understanding of peace between

two states would suggest.

First, it is a peace that requires first the peace within man (a harmony of body and soul), then a peace

between man and God. Augustine defines this latter peace as man acting in accordance with God’s

eternal law; that is the law, in contrast to man’s law and natural law, which is only known to God and

which can only be approximated but never be perfectly understood through man’s conduct of reason.

In his apt formula Augustine juxtaposes the two laws as man living by the love of God (in both

meanings, genitivus subjectivus and genetivus objectivus) to man living by the love of man.

Augustine continues to introduce, next to the virtue ethical and theological dimensions of peace, a

political dimension of peace – the well-ordered concord between man and man. This well ordered

concord is a quality that applies to different forms of relationships: in the family as domestic peace

and within the state (a first allusion to social contracts) as civil peace. In chapter 15 of book IV

Augustine extends this universal peace based on well-ordered concord also to kingdoms amongst each

other. The condition of the well-ordered concord between kingdoms can, therefore, be seen as a

precursor to Kelsen’s Grundnorm known as the principle dominant in Roman Law ‘pacta sunt

servanda’. Finally Augustine adds the spiritual dimension to universal peace, which goes far beyond






classic eudaimonia in being the ‘harmonious enjoyment of God, and of one another in God.’ This

harmony in and through God encompasses the tranquility of order and can only be enjoyed in the

tranquility of order. Vis-à-vis God this order based on obedience of faith and vis-à-vis man (read:

equals) it is based on concord.

When Augustine says that the existence of peace is the condition of the possibility of war to exist, he

argues this analogous to the classical idea of evil as the privation of good (privatio boni – book XII

chapter 9:‘For evil has in itself no substance, rather the loss of what is good had received the name

evil’); Subsequently, Augustine defines war as a privation or corruption of peace. This idea goes back

to Aristotelian and Platonic thinking that a thing is called good if it fulfills its nature and bad if it falls

short of fulfilling its perfect form.

In other words, Augustine understands peace as the state of nature, quite in contrast to Hobbes, who

sees the fight of one against the other as the state of nature. This view of Augustine stems from the

fact that he imagines all things created by God as per se created as good and corrupted through the

acts of others. This should suffice to show that neither peace nor (just) war nor politics in Augustinian

thought can be understood independently of his theology.

Turning to Immanuel Kant’s essay on perpetual peace, no other individual piece by Kant has been

more often reproduced than this essay. No other individual piece by Kant has been more often

reproduced than this essay. With some witty irony Kant imitates the legal structure of a peace treaty

by dividing the essay into two main sections and two appendices, the latter being added to the second

edition of 1797. The first part comprises six preliminary articles (Präliminarartikel) defining the

absolute ‘must not’ commands in international law: 1) No peace should be made if the peace treaty

serves as the basis of a future war; 2) No state should be consumed by inheritance, exchange,

purchase or bestowment; 3) Standing armies (miles perpetuus) should be eliminated in the future; 4)

No fiscal dependencies should be made which interfere with international affairs; 5) There should be

no political interference with the business of other states; and 6) No state during wartime should

commit acts, which make a mutual peace treaty in future impossible (e.g. breach of capitulation,

espionage, use of poison etc.).

The second part comprises three definitive articles in which Kant distinguish positively between three

dimensions of the conditions of the possibility of perpetual peace. They are; 1) On a constitutional

level only a republican state can guarantee peace; 2) On the level of international law a feral union of

sovereign states must be established which, on the one hand protects the particularity and sovereignty

of each member and, on the other functions as collective authority without any primus inter pares; 3)






Finally, global civil rights (Weltbürgerrecht) should be limited to the conditions of general


Within the scope of this essay we will not have space to analyse the brilliant and complex appendices

of the Friedenschrift in detail. We would have to examine Kant’s distinction between the figure of a

moral politician juxtaposed to the figure of a moralizing politician, to elucidate the role nature plays

in supporting the possibility of a perpetual peace, the importance of duty and obedience to a priori

universal moral norms and finally to discuss Kant’s ‘transcendental and positive principle of public

law’, that is publicity.

We would rather like to limit our comparison to Kant’s explicit reference to Augustine in the first

addition to the third definitive article entitled, ‘On the guarantee of perpetual peace’. In this part of the

treatise the author raises the question how perpetual peace can be ensured. Given the obvious

wickedness of man and accepting Hobbes negative anthropology of ‘war of every man against every

man’, the problem is to demonstrate the possibility of peace. In an extensive footnote Kant, discussing

nature as opposed to free will, alludes to Augustine (Confessions 12, 18) distinguishing between three

types of providence: foundational providence (providential conditrix; semel iussit, simper parent),

governing providence (providential gubernatrix) and leading providence (providential directrix).

What is important here is, that for Kant, it is nature which is divinely inspired and which ultimately

enables us to reach a state of perpetual peace.

In Augustine, on the contract, peace was always seen as gift from God. Peace, in the end is grace. In

Kant’s conception of perpetual peace, nature provides the grounds for peace because of its ‘divine

providence’. This can be best illustrated by the reason Kant gives for the peace preparing role nature

place outlined in the three definitive articles. On the level of constitutional law peace is possible

because, by nature, human beings should act according to moral law and that implies that if they

ought to act according to moral law, they can act according to moral law. On the level of international

law, nature has made the family so diverse in languages, religious beliefs, customs and attitudes so

that this plurality prevents hegemony and the despotism of one single political unity. Finally, on a

global level, nature, according to Kant, provides the grounds for peace because it has implanted in

human beings the desire to trade with each other. Therefore, so the optimistic view of Kant, global

trade prevents the outbreak of non-economically stimulated conflicts. At least, the last premise can be


More important though, than the grounding function of nature in warranting perpetual peace is the use

of practical reason. If the former was the objective condition for perpetual piece, than the latter is the






subjective condition of peace. In the end, everything depends on the moral politician who follows the

a priori moral law of practical reason and who is assured to be supported by nature’s providence.

What we can see in Kant’s work is a remarkable transformation of Augustine’s understanding of

peace as divine gift. With Kant and, one might say with modernity, the agent of peacemaking is no

longer God but man while the tool of peacemaking, namely concord, remains the same. The church,

as community simul iustus et peccator (being justified and sinner at the same time), at the same time

temporal and spiritual on its pilgrimage to becoming the city of God and therefore towards universal

peace inspired by God has been transformed to the community of global citizens guided by the

universal moral law instilled through practical reason. The state is seen in Kant as singular entity as

opposed to classical virtue ethics related philosophy, which saw a need for the autonomy of individual

morality and its incommensurable role in politics. Even without taking into consideration the

theological dimension advocated by Augustine, universal peace goes beyond perpetual peace insofar

as perpetual peace is a negative peace – an absence of war. It cannot be much more as Kant’s vision

of humanity and its state of nature is inherently Hobbesian, whereas the Augustinian state of nature is

peace by God’s grace and creation. But both see similarly the central role of practical reason (in terms

of virtue ethics phronesis or practical wisdom) in the process of reaching from war to peace.

Recommended Readings

Augustine. 1887. De Civitate Dei contra Paganos (City of God Against the Pagans). Translated by

Marcus Dods. From Nicene and Post-Nicene Fathers, First Series, Vol. 2. Edited by Philip Schaff.

Buffalo, NY: Christian Literature Publishing Co.: Book 19, Chapter 13.

Figgis, John Neville. 1921. The Political Aspects of S Augustine’s ‘City of God’. London: Longmans,

Green, and Co.

Kant, Immanuel. 1795. Zum ewigen Frieden. Ein philosophischer Entwurf. Königsberg: Friedrich

Nicolovius. Online access to the german Akademie Ausgabe available at

<> last accessed January 20, 2014.

Hobbes, Thomas. 1651. Leviathan or The Matter, Forme and Power of a Common Wealth

Ecclesiasticall and Civil. (In Thomas Hobbes. 1839-45. The English Works of Thomas Hobbes of

Malmesbury; Now First Collected and Edited by Sir William Molesworth, Bart. London: Bohn. Vol.

3. Available at: <> last accessed January 20, 2014.

Galtung, Johan. 1969. “Violence, Peace, and Peace Research.” Journal of Peace Research 6, no. 3: