Leibniz

Modern philosophy

Leibniz was a German philosopher of the seventeenth century (1646-1716). He was a universal mind: in mathematics, he invented differential calculus, and in physics, he formulated the law of conservation of energy. He was born in Leipzig, defended his doctorate in law in Nuremberg and became a librarian at the court of Hanover. In philosophy, he is known for his Monadology and his demonstration of the existence and perfection of God, the author of the best of all possible worlds — a notion Voltaire famously ridiculed.

On this page dedicated to Leibniz, discover summaries of his works, a bibliography, videos, a detailed biography, and a list of his major works.

The Works of Leibniz Summarised on This Site

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Monadology

In the Monadology, Leibniz sets out his famous principle of sufficient reason and defines the monad as the element of which the whole universe is made

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Bibliography

Here are the essential books if you wish to gain a better understanding of this author's thought:

Jolley, Nicholas, (ed.), 1995. The Cambridge Companion to Leibniz. Cambridge University Press.
Mates, Benson, 1986. The Philosophy of Leibniz: Metaphysics and Language. Oxford University Press.
Smith, Justin E. H., 2011. Divine Machines. Leibniz and the Sciences of Life, Princeton University Press.
Connelly, Stephen, 2021. Leibniz: A Contribution to the Archaeology of Power, Edinburgh University Press
Borowski, Audrey, 2024. Leibniz in His World: The Making of a Savant. Princeton University Press.

Biography: Life of Leibniz

Youth

Leibniz was born in 1646 in Leipzig, in Saxony, at the close of the Thirty Years' War that had ravaged Europe.

His father, a jurist, died when he was just six years old. A precocious child of great intellectual curiosity, he taught himself Latin.

By the age of fifteen, he was well-versed in Greek and Latin literature, and was already engaging with the thinkers of his own day, including Descartes.

After obtaining his baccalaureate in ancient philosophy, he went to Jena to study mathematics in 1663, then to Nuremberg to study chemistry, before enrolling at the Faculty of Law in Leipzig. In 1666, having taken his doctorate in law at the University of Altdorf, he turned down an offer of a teaching post.

He met Baron von Boyneburg, who would become his patron — an encounter that proved decisive for the rest of his career. He became his assistant, his legal counsel and his friend.

In 1670, he was entrusted with a political appointment: adviser to the Chancellery of the Electorate of Mainz. While living there, he worked on a wide-ranging reform of the law and began writing political and scientific works.

The Journey to France and the First Discoveries

In 1672, he was sent to Paris on a diplomatic mission, charged with attempting to secure peace between France and Germany.

For four years, he lived in Paris, where he met leading scientists of the day, among them the mathematician and astronomer Huygens and the philosopher Malebranche. He was at the centre of a vast network of intellectual exchange spanning all of Europe, with no fewer than 1,100 correspondents.

He worked on squaring the circle and developed infinitesimal calculus. Newton also claimed credit for this discovery, and a dispute between the two men endured until the end of Leibniz's life.
It now appears that Newton was the first to conceive the idea, but that Leibniz published it first; neither, however, plagiarised the other, as both had pursued their research independently.

In 1673, he designed a calculating machine that improved on the one Pascal had built. He travelled to London to present his prototype and was elected a Fellow of the Royal Society. He used the visit to study Newton's work.

Back in Paris, he brought his most fundamental mathematical discovery to completion: differential and integral calculus.

In 1676, he met Spinoza in The Hague and was able to read the contents of The Ethics — though he later denied this, given the controversial reputation that surrounded Spinoza's name.

That same year he returned to Germany where, following the death of his patron, he was in need of a new position.

Though he hoped to return to France, Colbert refused him a pension. He therefore remained in Germany and was appointed librarian to the Duke of Brunswick-Lüneburg, entering the service of the House of Hanover — in what is now Lower Saxony — a post he held for forty years.

Fruitful Years

Once his situation was settled, Leibniz entered a period of intense creative activity. These forty years were extraordinarily productive. It was during this time that he wrote the greater part of his philosophical works.

He also turned his mind to mathematics, religion and physics. In 1684, he published an article on differentials.

The year 1686 proved especially fertile:

In mathematics, he published his article on integrals.

In physics, he developed his theory of dynamics, based on the conservation of force — what we would now call energy.

In philosophy, he published his Discourse on Metaphysics, written in French.

Leibniz was equally at home in German (his mother tongue), Latin (the language of scholarship) and French (the language of the German courts).

In 1691, he wrote his work on dynamics, in which he used the terms "energy" and "action" for the first time.

In 1699, he was admitted to the Académie des Sciences in Paris. He then set about establishing a similar institution in Germany: the Brandenburg Society of Sciences — later the Berlin Academy — was founded at his instigation.

A 1703 issue of the Comptes Rendus of the Académie des Sciences de Paris contains an article by Leibniz setting out the principles of binary calculus (using only 0 and 1). Nearly two hundred and fifty years before the advent of computing, this was the very principle on which computers would come to operate. Leibniz himself, however, concluded that he could see no practical use for this mode of calculation, beyond what he called an "essential" beauty: the elegance of the relationships between numbers.

Old Age

In 1710, he published his Essays of Theodicy, and four years later completed the Monadology, written in French — though this work only appeared posthumously.

He conceived the project of an encyclopaedia, or "universal library", that would make knowledge accessible to all, but this ambition never came to fruition.

He was recognised as the foremost intellectual in Europe, receiving pensions from several royal courts and corresponding with kings and queens — among them Sophie Charlotte of Hanover, the first Queen of Prussia.

Despite his fame, he died in 1716 in Hanover in complete solitude. No tribute was paid to him, with the sole exception of the Académie de Paris. He left behind no fewer than 200,000 pages of manuscript.

Main Works

Discourse on Metaphysics
New Essays on Human Understanding
Essays of Theodicy on the Goodness of God, the Freedom of Man and the Origin of Evil
The Monadology