Hugo Grotius
Early Modern · Europe · 1583 to 1645
Dutch lawyer who argued that nations are bound by shared rules, even in war, and so a founder of international law.
What it is
Hugo Grotius (1583 to 1645) was a Dutch jurist, philosopher and statesman, and a towering figure of seventeenth-century thought. He was born in Delft and was a prodigy who wrote elegies at eight. He lived a dramatic life: he held high office, was imprisoned and escaped, and survived a shipwreck, and still produced an astonishing number of works.
He is best known for his contributions to natural law, the idea that there are standards of right and wrong that do not depend only on what rulers command. His book On the Law of War and Peace made the moral status of war its central question, and it is often counted among the foundations of the modern law of nations.
The main ideas
- Natural law. He built a theory of normativity, of what binds people, that is about much more than politics, though politics was his chief concern.
- The law of war. He asked when it is lawful to wage war at all, and how a war may rightfully be conducted. These are the questions later called the right to go to war and right conduct in war.
- Law between peoples. His thinking about war and peace is closely tied to his own work as a diplomat and as a statesman.
- Many kinds of writing. He wrote critical editions, essays on the events of his day and large treatises.
- A demanding style. His prose and his method make demands of the reader, with many references and authorities.
What it looks like in practice
Imagine two states in a dispute, each claiming that its cause is just. Grotius would ask two separate questions: whether either has a rightful cause for going to war at all, and, if they do fight, what limits on conduct apply even in a justified war. This is an illustration of his line of questioning, not a passage from his writing.
Books and moments
- De iure praedae (on the law of prize and booty) is an earlier work on the law of war.
- De iure belli ac pacis (On the Law of War and Peace) is his masterpiece on natural law and war.
- Pontifex Romanus is a collection of six essays on recent political events, published while he was on an embassy to France.
Questions and criticism
- A demanding style. The style of his prose is the first thing readers notice and a barrier for some.
- How original was he? Scholars distinguish how original he was from how influential, and the two do not always match.
- Can law restrain war? It is fair to ask how far any law of war can bind states that decide for themselves when to fight.
Close neighbours
The page on Thomas Hobbes shows another thinker of the same century who wrote about law, war and the state.
Written by epchē in our own words, and checked against independent sources on 29 October 2026. The sources are listed below.
Who they connect to
Influenced
- John Locke · Locke drew on his natural-law writing when he described rights and government. (scholars disagree about this link)
Influenced by
- Francisco Suarez · Grotius drew on his writing on natural law and the law of nations. (scholars disagree about this link)
Other Early Modern thinkers
- Thomas Hobbes · 1588 to 1679
- Blaise Pascal · 1623 to 1662
- Mary Astell · 1666 to 1731
- Giambattista Vico · 1668 to 1744
Sources we used
- Hugo Grotius · Stanford Encyclopedia of Philosophy, read on 29 October 2026
- Hugo Grotius · Wikipedia, read on 29 October 2026