
''De iure belli ac pacis'' (English: ''On the Law of War and Peace'') is a 1625 work by Dutch
jurist
A jurist is a person with expert knowledge of law; someone who analyzes and comments on law. This person is usually a specialist legal scholar, mostly (but not always) with a formal education in law (a law degree) and often a Lawyer, legal prac ...
and philosopher
Hugo Grotius
Hugo Grotius ( ; 10 April 1583 – 28 August 1645), also known as Hugo de Groot () or Huig de Groot (), was a Dutch humanist, diplomat, lawyer, theologian, jurist, statesman, poet and playwright. A teenage prodigy, he was born in Delft an ...
, which is widely regarded as a foundational text in the development of
international law
International law, also known as public international law and the law of nations, is the set of Rule of law, rules, norms, Customary law, legal customs and standards that State (polity), states and other actors feel an obligation to, and generall ...
.
First published in Paris, the work sets out to establish a legal framework for war and peace based on
natural law
Natural law (, ) is a Philosophy, philosophical and legal theory that posits the existence of a set of inherent laws derived from nature and universal moral principles, which are discoverable through reason. In ethics, natural law theory asserts ...
, reason, and customary norms among nations (
jus gentium
In Roman law and legal traditions influenced by it, ''ius gentium'' or ''jus gentium'' (Latin for "law of nations" or "law of peoples") is the law that applies to all ''gentes'' ("peoples" or "nations"). It was an early form of international law, ...
).
Several editions of the work appeared during Grotius’s lifetime; the final, published in Amsterdam in 1646, is widely regarded by scholars as the version most faithful to his authorial intentions, reflecting his mature legal and philosophical views.
''De iure belli ac pacis'' enjoyed enduring influence and widespread circulation across Europe. It was reprinted in numerous editions—over 70 identified in major bibliographies, including translations into several European languages—demonstrating its importance across confessional and national boundaries. The work remained a central reference in the study of law and political theory, taught in academic institutions for centuries, and continues to be cited in debates surrounding just war theory, state sovereignty, and the principles of international law.
The work builds upon earlier ideas, particularly those of
Alberico Gentili
Alberico Gentili (14 January 155219 June 1608) was an Italian jurist, a tutor of Queen Elizabeth I, and a standing advocate to the Spanish Embassy in London, who served as the Regius Professor of Civil Law at the University of Oxford for 21 ye ...
in ''De iure belli'' of
1598 as demonstrated by
Thomas Erskine Holland and was influenced by Spanish scholastics such as
Francisco de Vitoria
Francisco de Vitoria ( – 12 August 1546; also known as Francisco de Victoria) was a Spanish Roman Catholic philosopher, theologian, and jurist of Renaissance Spain. He is the founder of the tradition in philosophy known as the School of Sala ...
and
Francisco Suárez
Francisco Suárez (; 5 January 1548 – 25 September 1617) was a Spanish Jesuit priest, philosopher and theologian, one of the leading figures of the School of Salamanca movement. His work is considered a turning point in the history of second ...
. Grotius composed much of the text while imprisoned in the Netherlands and completed it in 1623 at Senlis, with the assistance of
Dirck Graswinckel.
Historical context and purpose
Grotius wrote ''De jure belli ac pacis'' against the backdrop of the
Thirty Years' War
The Thirty Years' War, fought primarily in Central Europe between 1618 and 1648, was one of the most destructive conflicts in History of Europe, European history. An estimated 4.5 to 8 million soldiers and civilians died from battle, famine ...
(1618–1648), a period of religious and political upheaval that witnessed extreme violence across Europe. Grotius, then living in exile in France after escaping imprisonment for his involvement in religious-political controversies in the
Dutch Republic
The United Provinces of the Netherlands, commonly referred to in historiography as the Dutch Republic, was a confederation that existed from 1579 until the Batavian Revolution in 1795. It was a predecessor state of the present-day Netherlands ...
, sought to create a rational legal order to restrain the conduct of war and minimize bloodshed.
In the ''
Prolegomena'' to the treatise, Grotius famously observed the absence of restraint in warfare:
“''Throughout the Christian world I observed a lack of restraint in relation to war, such as even barbarous nations should be ashamed of.''” (''Prolegomena'', 29)
Grotius believed that even in a world of independent sovereigns with no higher adjudicating authority, shared principles of
justice
In its broadest sense, justice is the idea that individuals should be treated fairly. According to the ''Stanford Encyclopedia of Philosophy'', the most plausible candidate for a core definition comes from the ''Institutes (Justinian), Inst ...
and
law
Law is a set of rules that are created and are enforceable by social or governmental institutions to regulate behavior, with its precise definition a matter of longstanding debate. It has been variously described as a science and as the ar ...
could regulate behavior between states. Drawing from
Stoic philosophy
Stoicism is a school of Hellenistic philosophy that flourished in ancient Greece and Rome. The Stoics believed that the universe operated according to reason, ''i.e.'' by a God which is immersed in nature itself. Of all the schools of ancient p ...
,
Roman law
Roman law is the law, legal system of ancient Rome, including the legal developments spanning over a thousand years of jurisprudence, from the Twelve Tables (), to the (AD 529) ordered by Eastern Roman emperor Justinian I.
Roman law also den ...
, and
Christian theology
Christian theology is the theology – the systematic study of the divine and religion – of Christianity, Christian belief and practice. It concentrates primarily upon the texts of the Old Testament and of the New Testament, as well as on Ch ...
, he sought to construct a body of international norms grounded in
natural reason
Reason is the capacity of consciously applying logic by drawing valid conclusions from new or existing information, with the aim of seeking the truth. It is associated with such characteristically human activities as philosophy, religion, scien ...
and universally applicable principles.
Structure and philosophical foundations
Grotius structured his work around a multi-layered system of norms:
* Natural law, derived from human reason and inherent sociability
*
Law of nations
International law, also known as public international law and the law of nations, is the set of rules, norms, legal customs and standards that states and other actors feel an obligation to, and generally do, obey in their mutual relations. In in ...
, based on customary practice among states
*
Divine law
Divine law is any body of law that is perceived as deriving from a Transcendence (religion), transcendent source, such as the will of God or godsin contrast to man-made law or to secular law. According to Angelos Chaniotis and Rudolph F. Peters, di ...
, drawing from Christian scripture
* Utility-based arguments, used pragmatically when moral arguments failed
This structure allowed Grotius to address multiple audiences—religious and
secular
Secularity, also the secular or secularness (from Latin , or or ), is the state of being unrelated or neutral in regards to religion. The origins of secularity can be traced to the Bible itself. The concept was fleshed out through Christian hi ...
,
Catholic
The Catholic Church (), also known as the Roman Catholic Church, is the List of Christian denominations by number of members, largest Christian church, with 1.27 to 1.41 billion baptized Catholics Catholic Church by country, worldwid ...
and
Protestant
Protestantism is a branch of Christianity that emphasizes Justification (theology), justification of sinners Sola fide, through faith alone, the teaching that Salvation in Christianity, salvation comes by unmerited Grace in Christianity, divin ...
—and to advocate for a system of legal restraint that could be universally acknowledged, even in the absence of shared faith.
One of the most famous and controversial claims in the book is found in ''Prolegomena'', section 11:
''“Et haec quidem quae iam diximus, locum aliquem haberent etiamsi daremus, quod sine summo scelere dari nequit, non esse Deum, aut non curari ab eo negotia humana.”''
Translated:
“What we have been saying would have a degree of validity even if we should concede that which cannot be conceded without the utmost wickedness: that there is no God, or that the affairs of men are of no concern to Him.”
This statement is often summarized by the phrase ''etsi Deus non daretur'' (“as if God did not exist”). While some scholars have interpreted this as an attempt to secularize law, others argue that Grotius's secularization was hypothetical rather than absolute. In practice, Grotius regularly appealed to religious norms to support his arguments when purely rational justifications proved inadequate.
Just war theory and legal innovations
Grotius's work integrated elements of
just war theory
The just war theory () is a doctrine, also referred to as a tradition, of military ethics that aims to ensure that a war is morally justifiable through a series of #Criteria, criteria, all of which must be met for a war to be considered just. I ...
into a legal structure. He distinguished between:
* Just causes for war (e.g., self-defense, recovery of property, punishment of wrongdoing)
* Just conduct during war (proportionality, discrimination between combatants and non-combatants)
Because there was no international judge to resolve disputes, Grotius argued that war must sometimes be tolerated as a means of enforcement, but only within strict legal and moral bounds. He also developed an early theory of criminal responsibility of states, claiming that states could be punished for acts of aggression, much like individuals for crimes.
Legacy and influence
''De jure belli ac pacis'' had an enormous influence on the development of modern international law. Grotius is often referred to as the “father of international law,” though this title is sometimes shared with or contested by other figures such as Gentili and Suárez.
Grotius's ideas were influential for later legal thinkers such as
Samuel Pufendorf
Samuel von Pufendorf (; ; 8 January 1632 – 26 October 1694) was a German people, German jurist, political philosopher, economist and historian. He was born Samuel Pufendorf and Nobility, ennobled in 1694; he was made a baron by Charles XI of ...
,
Emer de Vattel
Emmerich de Vattel ( 25 April 171428 December 1767) was a philosopher, diplomat, and jurist.
Vattel's work profoundly influenced the development of international law. He is most famous for his 1758 work ''The Law of Nations''. This work was his ...
, and
Jean-Jacques Burlamaqui
Jean-Jacques Burlamaqui (; 24 June or 13 July 1694 – 3 April 1748) was a Genevan legal and political theorist who popularised a number of ideas propounded by other thinkers.
Life
Born in Geneva, Republic of Geneva, into a Calvinist family (des ...
, and laid foundational concepts later enshrined in the
Geneva Conventions
upright=1.15, The original document in single pages, 1864
The Geneva Conventions are international humanitarian laws consisting of four treaties and three additional protocols that establish international legal standards for humanitarian t ...
,
UN Charter
The Charter of the United Nations is the foundational treaty of the United Nations (UN). It establishes the purposes, governing structure, and overall framework of the United Nations System, UN system, including its United Nations System#Six ...
, and other instruments of international law.
Modern scholars have debated Grotius's legacy.
Michael Walzer
Michael Laban Walzer (born March 3, 1935) is an American Political theory, political theorist and public intellectual. A professor emeritus at the Institute for Advanced Study (IAS) in Princeton, New Jersey, he is editor emeritus of the left-win ...
praised him for embedding just war principles into legal norms, while Richard Tuck pointed out Grotius’s continued acceptance of
imperial and
commercial
Commercial may refer to:
* (adjective for) commerce, a system of voluntary exchange of products and services
** (adjective for) trade, the trading of something of economic value such as goods, services, information or money
* a dose of advertising ...
warfare, suggesting he remained an “enthusiast for war around the globe.”
References
Further reading
*Cornelis van Vollenhoven. ''On the Genesis of De Iure Belli ac Pacis''. Amsterdam: Koninklijke Akademie van Wetenschappen, 1924.
;
;
Translations :
*Francis W. Kelsey, with the collaboration of Arthur E. R. Boak, trans. ''De iure belli ac pacis libri tres''. Washington, D.C.: Carnegie Institution of Washington, 1913–1925 (reprint: Buffalo, NY: William H. Hein, 1995).
*Stephen C. Neff, trans. ''Hugo Grotius: On the Law of War and Peace''. Student edn. Cambridge: Cambridge University Press, 2012.
External links
*{{Commonscatinline
Online text (English text, abridged, PDF)Online Text (English text, unabridged, HTML and PDF)Online text (Original Latin text)
1625 books
International law
Books by Hugo Grotius
Law books
Legal history of the Dutch Republic
1625 in law
17th-century books in Latin