Politics/Ethics

War and Peace

Is war an ineradicable feature of human life, or can lasting peace be achieved?

Ancient Greek
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Hellenistic/Roman
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Patristic/Medieval
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Renaissance/Early Modern
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Enlightenment
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19th Century
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finis

The Reading List

Follow this thread through the primary texts, in the order they enter the conversation.

1. Homer, (complete, or at minimum Books I, VI, IX, XVI, XXII, XXIV)
2. Thucydides, , Book V (the Melian Dialogue)
3. Plato, Book II; Book I
4. Aristotle, Book VII, Chapters 13–15
5. Virgil, , Books II, VII–XII
6. Augustine, Book XIX, Chapters 7, 12–13, 28
7. Aquinas, II-II, Questions 29 (on peace) and 40 (on war)
8. Machiavelli, , Chapters 14 and 18
9. Hobbes, , Part I Chapter 13; Part II Chapter 17
10. Locke, , Chapters 2–4
11. Montesquieu, , Books I and X
12. Rousseau, , Book I; Discourse on Inequality, Part II
13. Kant, ;
14. Hamilton and Madison, Nos. 6, 7, 15–16
15. Hegel, , Part III, paragraphs 324–340
16. Tolstoy, (complete, or the Borodino sequence and the Epilogue)
Read as text

Every thinker on War and Peace, in chronological order.

Homer

c. 8th century BC · Ancient Greek

War is terrible and glorious at once. It is simply part of the human condition.

Homer does not argue for or against war. He presents it. The remains among the most sustained portraits of armed conflict in the Western tradition. "Grievous war" is his repeated epithet; "pale fear" and "black death" are the colors of battle wherever Ares reigns, the "blood-stained bane of mortals" and "stubborn god of war." Yet the poem's heroes, Achilles and Hector, find in battle a supreme test of excellence. Glory (kleos) is won on the field or not at all.

What Homer establishes, and what later writers repeatedly return to, is war's mixed character. Battle lets loose a fury that sweeps human nature to extremes of nobility and baseness, to acts of heroic strength and of cringing weakness. On the plains of Troy, as later on the Russian steppes in Tolstoy, war appears as a mixed thing: occasions for courage and magnanimity, and even for a kind of compassion, set within a spectacle of agony. Homer does not resolve this tension. He lets it stand. The historian who measures contestants and keeps the score of victories may dwell on progress in the art of war; the poet of any century, Homer or Tolstoy, Virgil or Shakespeare, tends to see war's human features as largely unchanged even when its weapons and organization alter.

The in its entirety, but especially Achilles' choice between a long, obscure life and a short, glorious one (Book IX), and the meeting of Hector and Andromache (Book VI), where domestic love and martial duty stand in irreconcilable conflict.

*Iliad*, Books VI and IX

Homer supplies the raw material of war as lived experience. Philosophers, theologians, and political theorists who follow will ask what causes war, whether it can be justified, and whether lasting peace is possible. Those questions are treated under related ideas as well, among them Emotion, Life and Death, and Virtue and Vice. The conversation begins here, with the face of battle left open rather than explained away.

Key work: Iliad

Thucydides

c. 460–400 BC · Ancient Greek

War is inevitable because power, fear, and self-interest govern relations between states.

Where Homer shows war's face, Thucydides examines its political logic. His is often read as an early statement of political realism. In the Melian Dialogue he records the Athenian claim that "the strong do what they can and the weak suffer what they must." On this account, war is not caused by the anger of gods or by the ambitions of individual heroes alone. It arises from the structural dynamics between states: from the growth of Athenian power and the fear that growth inspired in Sparta. The historian is attentive to numbers and armament, and no less to the occasions and pretenses under which cities go to war.

Thucydides also makes an observation that later writers will find decisive for the nature of peace. Periods of armistice, he holds, are not genuine peace but part of the war. "Only a mistaken judgment can object to including the interval of treaty in the war. Looked at by the light of facts it cannot be rationally considered a state of peace, where neither party either gave or got back all that they had agreed upon." Hermocrates the Syracusan is reported to the same effect: men go to war for their interests and, if they separate without having as they think their rights, will go to war again. The absence of fighting, on this view, is not the same as a well-ordered peace. The point anticipates, in historical form, what Hobbes will later state as a distinction between battle and the state of war.

"The strong do what they can and the weak suffer what they must."

*History of the Peloponnesian War*, Book V (Melian Dialogue)

"No one is forced to engage in war by ignorance, or kept out of it by fear, if he fancies there is anything to be gained by it."

Hermocrates' speech

Thucydides thus places one pole of the debate: that power, fear, and interest govern relations between independent communities. Every later writer who argues that peace is achievable must meet this challenge. The causes of war among states, and the distinction between truce and peace, reappear under the ideas of State, Government, and Revolution, where civil strife is treated more fully as a special case of discord within a single community.

Key work: History of the Peloponnesian War

Responds to: Homer

Plato

428–348 BC · Ancient Greek

War originates in greed, luxury, and appetite: a symptom of political and moral disorder.

Plato seems to see both sides of the question of war, though he does not give them equal weight. In the , Socrates proclaims the discovery that war is "derived from causes which are also the causes of almost all the evils in states, private as well as public." Those causes are the appetites: the desire for wealth and luxury that forces cities to expand beyond their borders and encroach on their neighbors. On this view, war is not rooted in human nature as such, but in the disordered soul and the disordered city. The moral psychology of desire, treated more fully under the ideas of Desire and Temperance, is thus joined to the political question of expansion and conflict.

In the , Cleinias the Cretan justifies his city's constant preoccupation with war on the ground that all cities are always at war with one another, and that what men call peace is only a name. The Athenian Stranger allows that laws devised primarily with a view to war may be partly justified insofar as they aim at courage; but he reminds Cleinias that insofar as such laws "regarded a part only, and not the whole of virtue," they are to be disapproved. "No one can be a true statesman," he says, "who looks only, or first of all, to external warfare; nor will he ever be a sound legislator who orders peace for the sake of war, and not war for the sake of peace."

"No one can be a true statesman, whether he aims at the happiness of the individual or state, who looks only, or first of all, to external warfare; nor will he ever be a sound legislator who orders peace for the sake of war, and not war for the sake of peace."

*Laws*, Book I

Plato thus shifts the discussion from what war is like to what causes it and how it stands to the ends of legislation. If war arises from disordered desire, then a moral and political remedy may be conceivable. That line of thought prepares the later treatment of just war and, still later, the argument that lasting peace is a duty of practical reason. Aristotle will restate the subordination of war to peace with greater precision; Augustine and Aquinas will give it a theological form.

Key work: Republic

Responds to: Homer, Thucydides

Aristotle

384–322 BC · Ancient Greek

War is a means, never an end. It exists for the sake of peace.

Aristotle agrees with Plato that war is somehow rooted in the nature of men and of cities, yet also looks upon war as transitory, even if recurrent. He frames the relation of war to peace with a precision that later writers often adopt. "The whole of life is divided into two parts, business and leisure, war and peace. There must be war for the sake of peace, business for the sake of leisure, things useful and necessary for the sake of things honorable." War is an instrument, and like all instruments it is judged by the end it serves. Men must be able to engage in business and go to war, but leisure and peace are better; they must do what is necessary and useful, but what is honorable is better.

If war is a means to peace, then a war that does not serve peace stands in need of justification. If leisure, and the intellectual and moral life it makes possible, is among the true purposes of political community, then a city permanently organized for war has misunderstood its own end. Aristotle does not develop a full doctrine of just war, but he supplies a premise on which such a doctrine may rest: war requires justification by reference to something beyond itself. The military virtues, and the place of the soldier in the city, belong also to the discussions of Courage, Virtue and Vice, and Citizen; the ranking of war below peace belongs to the larger account of Happiness and of the good life.

"Men must be able to engage in business and go to war, but leisure and peace are better."

*Politics*, Book VII, Chapter 14

Aristotle thus provides a philosophical framework (war as means, peace as end) that Augustine and Aquinas will later fill with theological content. His formulation also stands in tension with a purely realist account of power: if war is only a means, then power cannot be its own justification. Dante will later appeal to Aristotle's maxim that a plurality of authorities is disorder when arguing for a single world government; Aristotle himself, however, does not draw that conclusion for the world as a whole.

Key work: Politics

Responds to: Plato

Virgil

70–19 BC · Hellenistic/Roman

War is the cost at which the peace of empire is bought, and the hero who founds a lasting peace must bear the grief of the killings that were required to make it possible.

The begins in the fall of one city and ends in the foundation of the line that will raise another. Between lies a story of wars: those Aeneas has survived at Troy, the combats and pitched battles of the Italian campaign, and, held in prospect throughout, the wars by which Rome will come to rule the world. Virgil does not treat this sequence as mere setting for the hero's deeds. He treats it as the matter from which a lasting peace must be made, and as the cost at which the making is carried out. In the opening book, Jove predicts a Caesar destined to bound his domain with ocean and his glory with the stars; when Rome has conquered the world, the golden age of peace, or at least the pax Romana, is to supplant war's age of iron.

What gives the poem its distinctive treatment of the subject is the refusal to separate praise of imperial peace from acknowledgment of the grief attending the wars. The death of Pallas and the killing of Turnus are told in a tone that does not conceal what has been lost. Anchises in the sixth book declares the Roman vocation: to bear dominion over the nations and to impose the law of peace, to spare the humbled and to war down the proud. That declaration is not inconsistent with the lament that fills the poem for the young men, Trojan and Italian alike, who are killed before their time. Virgil does not present imperial peace as cheap. The tension between its necessity and its cost is what later readers often find most instructive. Some of the proud who are subjugated take a different view of peace imposed by arms; Tacitus reports Galgacus saying of the Romans that they create a wilderness and call it peace.

The treatment of war and peace in the raises questions continued under several other ideas. The justice of the imperial vocation belongs also to Justice and to State; the grief of the slain and the moral weight of killing belong to Emotion and to Life and Death; the relation of human warfare to the purposes of the gods is considered under God and Fate. Virgil's contribution is to link these under a single head: no peace that is not also a conquest, and no conquest that is not paid for in the suffering of those who made it and those who were subdued.

"But, Rome, 'tis thine alone, with awful sway, to rule mankind, and make the world obey ... to tame the proud, the fetter'd slave to free."

*Aeneid*, Book VI

"With a great groan his resentful life flies down into the shades."

*Aeneid*, Book XII

Augustine in the takes up this inheritance and presses it further. The peace of Rome, he argues, is a real but limited good, secured by wars that cannot be wholly justified from within the framework the pagan city supplied. Aquinas formulates conditions of just war partly by reflection on cases such as those the set before later readers. Writers from the medievals through Kant's treatments of perpetual peace continue the conversation Virgil framed: whether a lasting peace is possible, what its price is, and whether empire is the only instrument by which a great peace can be secured.

Key work: Aeneid

Responds to: Homer, Thucydides

Augustine

354–430 · Patristic/Medieval

War is a consequence of sin. Peace is the true desire of every heart, even those who wage war.

Augustine introduces the category of sin into the discussion of war. Animals "devoid of rational will," he observes, live "more securely and peaceably with their own kind than men," for "not even lions or dragons have ever waged with their kind such wars as men have waged with one another." It is not human nature as such but human fallenness that makes war endemic. The diagnosis is sharper than Plato's account of disordered appetite: the problem is a corruption of the will. Interior conflict and interior peace are treated more fully under Opposition and Happiness; here they bear on the social and political discussion.

Yet Augustine also insists that even those who wage war desire peace. "Every man seeks peace by waging war, but no man seeks war by making peace. For even they who intentionally interrupt the peace in which they are living have no hatred of peace, but only wish it changed into a peace that suits them better." Peace, he holds, consists in harmony and concord. "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 all things is the tranquillity of order." All wars, on this account, are waged that men may find a more perfect peace than that which they had before.

This does not make Augustine an optimist about earthly politics. He reflects soberly on Rome's imperial peace: the imperial city has endeavored to impose on subject nations not only her yoke but her language as a bond of peace, and many wars and much bloodshed have provided that unity. Even if hostile nations beyond the empire were wanting, the very extent of the empire produces social and civil wars. The earthly city will always be plagued by war; only the heavenly city enjoys true peace. After the family and the city, Augustine says, comes the world as a third circle of human society, yet he does not prophesy a single political community of all men under one government. He does, however, hold that the wise man will wage just wars when necessity requires, and will lament that necessity even as he wages them.

"Every man seeks peace by waging war, but no man seeks war by making peace."

*City of God*, Book XIX, Chapter 12

"The wise man will wage just wars. ... For if they were not just he would not wage them, and would therefore be delivered from all wars."

*City of God*, Book XIX, Chapter 7

Augustine synthesizes the classical insight that war is for the sake of peace with a Christian anthropology in which war is the fruit of sin. From this synthesis comes much of the just war tradition that Aquinas will later state systematically. The relation of earthly peace to heavenly peace, and of the city of man to the city of God, is continued under Theology, Religion, and State.

Key work: City of God

Responds to: Plato, Aristotle, Thucydides, Virgil

Thomas Aquinas

1225–1274 · Patristic/Medieval

War can be just, but only under strict conditions. Peace is the work of justice.

Aquinas takes Augustine's reflections on just war and gives them systematic form. A war is just, he holds, only if three conditions are met: it must be waged by a legitimate sovereign authority (not a private individual); it must have a just cause (the righting of a wrong); and it must be undertaken with the right intention (the advancement of good or the avoidance of evil, not revenge or cruelty). These conditions join questions of Government and Justice to the conduct of arms. The rights of war, the distinction between just and unjust warfare, and the laws governing its prosecution belong to this same inquiry.

On peace itself, Aquinas refines Augustine. Peace involves more than concord. "Wherever peace is, there is concord, but there is not peace wherever there is concord, if we give peace its proper meaning." The peace between men may consist in concord, "not indeed any kind of concord, but that which is well-ordered, through one man agreeing with another in respect of something befitting to them both." If one man agrees with another only through being forced, such concord is not really peace. Though charity or love produces the unity of peace, peace is also "the work of justice" indirectly, "insofar as justice removes the obstacles to peace." Without justice there may be truces and armistices, but not true peace. Thucydides' observation that intervals of treaty may still be part of war finds here a theological and juridical counterpart.

For men to be at peace with one another, Aquinas believes, each must be at peace with himself; yet "man's heart is not at peace, so long as he has not what he wants, or if, having what he wants, there still remains something for him to want." This explains why Augustine defined peace not simply as concord but as the tranquillity of order: by "tranquillity" is meant all the desires of each individual being set at rest together. Those who seek war and dissension, Aquinas reminds us, desire nothing but a peace they deem themselves not to have, and break a defective concord in order to obtain a peace in which nothing is contrary to their will.

"Wherever peace is, there is concord, but there is not peace, wherever there is concord, if we give peace its proper meaning."

*Summa Theologica*, II-II, Q. 29, A. 1

"In order for a war to be just, three things are necessary. First, the authority of the sovereign ... Secondly, a just cause is required ... Thirdly, it is necessary that the belligerents should have a rightful intention."

*Summa Theologica*, II-II, Q. 40, A. 1

Aquinas thus gives the just war tradition a definitive medieval formulation. His three conditions remain a framework for later discussion of when war may be undertaken. His insistence that coerced concord is not real peace anticipates the modern distinction between the mere absence of fighting and a positive peace ordered by justice. The same themes reappear under Law, Justice, and Government.

Key work: Summa Theologica

Responds to: Augustine, Aristotle

Niccolò Machiavelli

1469–1527 · Renaissance/Early Modern

War is the prince's primary concern. The question is not justice but survival.

Machiavelli does not so much refute the Augustinian and Thomistic account of just war as set it aside. The question he puts to the prince is not primarily moral but strategic. "A prince ought to have no other aim or thought, nor select anything else for his study, than war and its rules and discipline." When princes have thought more of ease than of arms, they have lost their states. The prince ought never to have the subject of war out of his thoughts, and in peace should addict himself more to its exercise than in war. To those who despair of lasting peace, or who accept war as recurrent, this advice may seem a kind of realism rather than a break with the tradition; yet it relocates the center of inquiry from justice to the preservation of the state.

War, for Machiavelli, "is not to be avoided, but is only deferred to your disadvantage." The prince who delays in order to save himself from war makes a serious mistake. In peacetime the wise prince studies war more intensively than in war itself. Machiavelli paraphrases Cicero's distinction between two ways of contesting, the one by law and the other by force: the first method proper to men, the second to beasts. He then adds that because the first is frequently not sufficient, it is necessary to have recourse to the second. The military arts and the formation of military policy, treated under the role of the prince and the soldier in the state, thus become the prince's chief study.

"A prince ought to have no other aim or thought, nor select anything else for his study, than war and its rules and discipline."

*The Prince*, Chapter 14

"It is not to be avoided, but is only deferred to your disadvantage."

*The Prince*, Chapter 3

Machiavelli therefore shifts the question from "When is war justified?" to "How is the state preserved by arms?" Later writers who seek to restore a moral framework for war and peace must reckon with his claim that moral categories may be secondary to political survival. Hobbes will give a more systematic account of the state of war and of government as its cure; the Federalists will apply related insights to the problem of union among separate sovereignties. The relation of arms to statecraft is continued under State, Government, and Prudence.

Key work: The Prince

Responds to: Augustine, Thomas Aquinas, Thucydides

Thomas Hobbes

1588–1679 · Renaissance/Early Modern

War is the natural condition of humanity without government.

Hobbes gives a rigorous formulation of war as a natural condition and, at the same time, a clear argument for its political cure. In the state of nature, without a common power to keep men in awe, there is "war of every man against every man." This war "consisteth not in battle only, or in the act of fighting; but in a tract of time, wherein the will to contend by battle is sufficiently known." The notion of time belongs to the nature of war as it does to the nature of weather: "as the nature of foul weather lyeth 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." Thucydides' observation that periods of armistice may still be part of war, and Cleinias' remark in Plato's that every city is in a natural state of war with every other, may anticipate this insight; full clarity on the distinction between battle and the state of war is not reached until Hobbes.

The cure is the formation of a commonwealth and the institution of government with sufficient coercive force to maintain law and secure peace. Within the commonwealth, peace reigns because the sovereign can arbitrate disputes. Anarchy and the condition of war, according to Hobbes, are one and the same: a condition in which each man, being a law unto himself and judge in his own case, must resort to force if he would impose his will upon, or resist the will of, another. But between commonwealths no such authority exists. "Kings and persons of sovereign authority, because of their independency, are in continual jealousies, and in the state and posture of gladiators; having their weapons pointing, and their eyes fixed on one another."

Hobbes does not exclude from peace all differences between men or even all discord, but only fighting or the need to resort to fighting as a way of settling differences. The distinction which Machiavelli paraphrases from Cicero (contesting by law versus contesting by force) is here given a structural rather than a merely strategic form. Law and government as conditions of civil peace are treated more fully under State and Government; the state of nature as a condition of men is continued under Nature and Liberty.

"During the time men live without a common power to keep them all in awe, they are in that condition which is called war; and such a war as is of every man against every man."

*Leviathan*, Part I, Chapter 13

"For war consisteth not in battle only, or the act of fighting, but in a tract of time, wherein the will to contend by battle is sufficiently known ... 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."

*Leviathan*, Part I, Chapter 13

Hobbes thus translates the problem of war from a primarily moral question into a structural one. War is caused not by sin or by appetite alone but by anarchy: the absence of a common judge. This insight becomes a premise for later arguments about international peace. Locke, Rousseau, Kant, and the Federalists will accept, with qualifications, that sovereigns independent of one another stand in a condition akin to the state of nature, and will debate what, if anything, can put an end to that condition among states.

Key work: Leviathan

Responds to: Niccolò Machiavelli, Thucydides, Aristotle

John Locke

1632–1704 · Enlightenment

The state of nature is not war itself, but inevitably lapses into it without civil society.

Locke draws a threefold distinction that Hobbes had left less sharp: the state of nature, the state of war, and the state of civil society. The state of nature is not itself war; it is the condition of men living together according to reason, without a common superior on earth. But because there is no common judge to resolve disputes, the state of nature tends to lapse into the state of war, which is force without right, or a declared design of force, wherever there is no common superior on earth to appeal to for relief. Want of a common judge with authority puts all men in a state of nature; the state of nature and the state of war may not be identical, yet the former, unlike civil society, easily passes into the latter if reason fails to settle differences.

Civil society is the remedy: "a state of peace amongst those who are of it, from whom the state of war is excluded by the umpirage which they have provided in their legislative for the ending all differences that may rise amongst any of them." But this peace extends only to fellow citizens. Between nations, the state of nature, and therefore the tendency toward war, persists. Locke agrees with Hobbes that all princes and rulers of independent governments are in a state of nature with respect to one another, and draws from this the implication that the government of each state must have the power of war and peace, leagues and alliances, in relation to everything external to itself. The whole community is one body in the state of nature in respect of all other states or persons out of its community.

"Force, or a declared design of force, upon the person of another, where there is no common superior on earth to appeal to for relief, is the state of war."

*Second Treatise*, Chapter 3

By distinguishing the state of nature from the state of war, Locke preserves the possibility that international relations need not be pure anarchy even without world government, if reason and agreement can hold. His framework also generates the next question: if civil society is the cure for war among individuals, is a more encompassing civil order the cure for war among nations? That question is taken up by Kant and the Federalists, and under the ideas of Government, Law, and State.

Key work: Second Treatise of Civil Government

Responds to: Thomas Hobbes

Montesquieu

1689–1755 · Enlightenment

War arises from the existence of separate societies, not from individual human nature.

Montesquieu accepts much of the Hobbesian and Lockean framework but locates the origin of war differently. It is not individuals in the pure state of nature who are primarily at war with one another; it is societies. As soon as man enters into a state of society he loses the sense of his weakness; equality ceases, and then commences the state of war. Once men form political communities, the communities themselves stand in a state of nature with respect to each other, and war follows. The laws of nations (the right of nations) should govern the conduct of war, just as civil laws govern the conduct of citizens. On this view, law may operate between nations as well as within them, short of abolishing the plurality of states.

"As soon as man enters into a state of society he loses the sense of his weakness; equality ceases, and then commences the state of war."

*The Spirit of the Laws*, Book I

Montesquieu thus contributes the thought that international law is a partial remedy for war among separate societies. Rousseau will press the claim that war is a relation between state and state rather than between man and man. The further question whether law among nations can suffice without a common superior, or whether only federal or world government can secure peace, is left for Kant, the Federalists, and later discussion under Law and Government.

Key work: The Spirit of the Laws

Responds to: Thomas Hobbes, John Locke

Jean-Jacques Rousseau

1712–1778 · Enlightenment

War is a relation between states, not between men. It is a consequence of political society itself.

Rousseau restates Montesquieu's alteration of Hobbes as a principle: "War is a relation, not between man and man, but between State and State." In Rousseau's account, men in the pure state of nature are solitary and comparatively peaceful. It is the formation of societies, with property, inequality, and competing interests, that produces war. Because states exist "in a state of nature among themselves," they experience "the inconveniences which had obliged individuals to forsake it. Hence arose national wars, battles, murders and reprisals, which shock nature and outrage reason." Individuals are enemies only accidentally, as members of contending bodies politic.

The question of peace is thereby altered. If war is not primarily a product of individual human nature but of political arrangements among separate societies, then different arrangements might in principle reduce or eliminate it. Rousseau does not develop this implication into a full plan for perpetual peace, but he lays groundwork that Kant will use. The social contract that establishes peace within the state leaves the relation of state to state unresolved; the same logic that drove individuals into civil society appears, on this view, among bodies politic themselves. Related questions of inequality, property, and the formation of political society are treated under Wealth, Slavery, and State.

"War then is a relation, not between man and man, but between State and State, and individuals are enemies only accidentally."

*The Social Contract*, Book I, Chapter 4

Rousseau's claim that war is structural to the plurality of states, rather than natural to the solitary individual, enables the later argument that transforming relations among states can end war. Kant will accept the diagnosis of a non-juridical condition among nations and will insist that practical reason commands an exit from that condition. Whether the exit requires a voluntary federation or something more is the question that follows.

Key work: The Social Contract

Responds to: Thomas Hobbes, Montesquieu

Immanuel Kant

1724–1804 · Enlightenment

Perpetual peace is a moral imperative. It requires a federation of free states.

Kant agrees with Hobbes that sovereign states are "naturally in a non-juridical condition" and that "this is a state of war, in which the right of the stronger prevails." Although that condition may not always appear as actual war and incessant hostility, it is wrong in itself, and nations contiguous to each other are bound mutually to pass out of it. Where some earlier writers stop, Kant insists that morality demands a further step. "The morally practical reason utters within us its irrevocable Veto: 'There shall be no War.'" He is not without ambivalence: a prolonged peace may favor a commercial spirit and tend to degrade national character, and war conducted with order and respect for civilians may even have something sublime about it. Yet the underlying purpose of war, he reflects, may be to prepare the way for a rule of law governing the freedom of states.

Kant envisions a "Universal Union of States analogous to that by which a Nation becomes a State," for only thus, he argues, could a real state of peace be established. He is careful, however, to distinguish this from a world empire on the model of the United States. He means "only a voluntary combination of different States that would be dissoluble at any time," not an indissoluble union founded upon a single political constitution. He admits the difficulty: with too great extension of such a union over vast regions, government of it and protection of its members may become impossible, and a multitude of such corporations might again bring round a state of war. Hegel will later dismiss any league that depends ultimately on particular sovereign wills as remaining infected with contingency.

Yet Kant refuses to yield completely to that difficulty. The question, he holds, is no longer whether perpetual peace is a real thing or not, or whether we deceive ourselves in adopting the former alternative. We must act on the supposition of its being real. We must work for what may perhaps not be realized, and thus may put an end to the evil of wars, which have been a chief interest of the internal arrangements of all states. In his idea of a universal history on a cosmo-political plan, he pictures nations, after many devastations, as driven toward a federation of nations as the inevitable issue of the necessity in which men involve one another. The moral duty to work for perpetual peace is prerequisite, on his account, to the highest political good.

"The morally practical reason utters within us its irrevocable Veto: There shall be no War."

*Science of Right*, Part II

"We must act on the supposition of its being real."

*Science of Right*, Part II

Kant thus takes the structural insight of Hobbes, Locke, and Rousseau (that war results from anarchy between states) and draws a moral conclusion: practical reason commands that we work to overcome that anarchy. His preferred instrument is a voluntary federation rather than a consolidated world state. Dante had argued more unreservedly for world government; Kant reaches a related conclusion only to qualify it. The Federalists supply a concrete case of federal union as a peace plan among formerly separate sovereignties, while Hegel denies that any such arrangement can abolish the necessity of war.

Key work: Perpetual Peace

Responds to: Thomas Hobbes, Jean-Jacques Rousseau

Hamilton & Madison

1787–1788 · Enlightenment

Federal union is the practical cure for war between states.

The Federalist papers apply the insight that independent sovereignties stand in a condition of mutual war or potential war to a concrete political problem: the fate of the American states under the Articles of Confederation. Hamilton argues that "a man must be far gone in Utopian speculations who can seriously doubt that, if these States should either be wholly disunited, or only united in partial confederacies, the subdivisions into which they might be thrown would have frequent and violent contests with each other." To look for a continuation of harmony between a number of independent, unconnected sovereignties in the same neighborhood would be to disregard the uniform course of events and to set at defiance the accumulated experience of ages.

The solution they propose is not a league or alliance, which depends on the obligations of good faith and therefore on each state's sovereign will, but a federal union with real governing authority. Hamilton admits that there is nothing absurd in a league between independent nations for certain defined purposes stated in a treaty, but he thinks Europe has taught how little dependence is to be placed on treaties that have no other sanction than good faith. He therefore attacks those who advocate perpetual peace between the states though dismembered and alienated from each other. Happy would it be, Madison says, if a remedy equally effectual could be established for the universal peace of mankind; yet the Federalists do not seriously recommend their prescription as a plan for the whole world, even while they see the generalization implicit in their reasoning.

"To look for a continuation of harmony between a number of independent, unconnected sovereignties in the same neighborhood, would be to disregard the uniform course of human events."

*Federalist* No. 6 (Hamilton)

The Federalists thus provide an empirical case. If thirteen formerly independent sovereignties can form a union and thereby put an end to war among themselves, the logic extends, in principle, to the question of peace among all sovereignties. Kant had distinguished a dissoluble voluntary combination of states from an indissoluble federal constitution on the American model; the Federalists insist that only the latter kind of union secures peace among its members. The argument is continued under Constitution, Government, and State, and under the conditions of peace among free governments.

Key work: The Federalist

Responds to: Thomas Hobbes, John Locke, Immanuel Kant

G.W.F. Hegel

1770–1831 · 19th Century

War is not an evil to be eliminated but a necessary force that preserves nations' ethical health.

Hegel is not ambivalent about war. Against much of the tradition from Plato through Kant, he argues that war is not to be regarded as an absolute evil, and that it is a necessary corrective for the corrosive influence of peace. "War is a state of affairs which deals in earnest with the vanity of temporal goods and concerns." It has the higher significance that by its agency "the ethical health of peoples is preserved in their indifference to the stabilization of finite institutions; just as the blowing of the winds preserves the sea from foulness which would be the result of a prolonged calm, so also the corruption in nations would be the product of prolonged, let alone 'perpetual,' peace." In peace, he holds, civil life continually expands, its departments wall themselves in, and in the long run men stagnate; as a result of war, nations are strengthened.

Hegel dismisses Kant's idea for securing perpetual peace by a league of nations. Any such arrangement "presupposes an accord between states; this would rest on moral and religious or other grounds and considerations, but in any case would always depend ultimately on a particular sovereign will and for that reason would remain infected with contingency." States are not private persons but completely autonomous totalities in themselves, and so the relation between them differs from a moral relation and a relation involving private rights. Self-interest, or a will for its own welfare pure and simple, is the highest law governing the relation of one state to another. When politics is alleged to clash with morals, the doctrine propounded rests, on Hegel's view, on superficial ideas about morality, the nature of the state, and the state's relation to the moral point of view.

There is no Praetor to judge between states; at best there may be an arbitrator or mediator, and even he exercises his functions contingently, in dependence on the particular wills of the disputants. Therefore, "if states disagree and their particular wills cannot be harmonized, the matter can only be settled by war." Wars occur when the necessity of the case requires. Sovereign states are in a state of nature in relation to each other, and, for Hegel, they must always remain so. The ethical and political benefits claimed for war, and the critique of perpetual peace as an ideal, reappear under State, Progress, and Constitution.

"The corruption in nations would be the product of prolonged, let alone 'perpetual,' peace."

*Philosophy of Right*, §324

"If states disagree and their particular wills cannot be harmonised, the matter can only be settled by war."

*Philosophy of Right*, §334

Hegel thus reasserts, after long development of moral and political argument for peace, a realist position: war is structural to the system of independent states, permanent in that system, and in a certain sense beneficial to the ethical health of peoples. Tolstoy will answer not with a rival theory of the state but with a portrait of war as force and chance that resists the claims of military genius and of philosophical necessity alike.

Key work: Philosophy of Right

Responds to: Immanuel Kant, Thomas Hobbes

Leo Tolstoy

1828–1910 · 19th Century

War is chaos, not strategy. The generals who claim to control it are deluded.

Tolstoy returns the discussion to the face of war as lived experience, in a manner that recalls Homer. is both a novel and an argument about history and command. Tolstoy scoffs at historians who stand in awe of military genius. Kutuzov's lack of plans, rather than Napoleon's air of outwitting all contingencies, may be the essence of great generalship; yet Tolstoy magnifies the campaign of 1812 as beyond comparison a great mass movement of humanity, from west to east and then from east to west. War is the domain of force and chance. Though it offers occasions for courage and magnanimity and even for compassion, the whole spectacle is one of agony, pervaded by darkness and dismay, torn bodies and ruined minds.

To Prince Andrew, "the aim of war is murder; the methods of war are spying, treachery, and their encouragement." Hegel answers that states are not private persons, and that the relation between them differs from a moral relation among individuals. Tolstoy does not refute that claim by counter-theory so much as by narrative. In the chaos and suffering of 1812 he finds moments of human connection (the brotherhood of soldiers, the compassion of enemies, the resilience of ordinary people caught in forces beyond their control) without granting that any plan or philosophy masters the event. The old prince puts the inevitability of war in another form: "Drain the blood from men's veins and put in water instead, then there will be no more war!" On this view, war is rooted in political arrangements and in the passions, fears, and loyalties that constitute human blood itself.

The poet of any century tends to see war's human features as unchanged even when its mechanical dress alters. Tolstoy stands with Homer in that company. Questions of historical causation, free will, and necessity are treated under Necessity and Contingency, History, and Fate; the moral consequences of war for combatants and for women and children belong also to Emotion, Happiness, and Life and Death.

"The aim of war is murder; the methods of war are spying, treachery, and their encouragement."

*War and Peace*, Book III (Prince Andrei)

"Drain the blood from men's veins and put in water instead, then there will be no more war!"

*War and Peace*, Book I (the old prince to Pierre)

Tolstoy stands against systematic accounts of war, whether Hegel's defense of its ethical function, Kant's moral program for perpetual peace, or Hobbes's structural analysis of anarchy and sovereignty. He insists that war as lived experience resists full reduction to any single formula. The conversation returns, as it began with Homer, to the human reality of battle, which no strategy, necessity, or claim of military genius fully captures.

Key work: War and Peace

Responds to: Homer, G.W.F. Hegel, Niccolò Machiavelli

The Reading List

1. Homer, (complete, or at minimum Books I, VI, IX, XVI, XXII, XXIV)
2. Thucydides, , Book V (the Melian Dialogue)
3. Plato, Book II; Book I
4. Aristotle, Book VII, Chapters 13–15
5. Virgil, , Books II, VII–XII
6. Augustine, Book XIX, Chapters 7, 12–13, 28
7. Aquinas, II-II, Questions 29 (on peace) and 40 (on war)
8. Machiavelli, , Chapters 14 and 18
9. Hobbes, , Part I Chapter 13; Part II Chapter 17
10. Locke, , Chapters 2–4
11. Montesquieu, , Books I and X
12. Rousseau, , Book I; Discourse on Inequality, Part II
13. Kant, ;
14. Hamilton and Madison, Nos. 6, 7, 15–16
15. Hegel, , Part III, paragraphs 324–340
16. Tolstoy, (complete, or the Borodino sequence and the Epilogue)