Georges-Louis Leclerc, Comte de Buffon

Origins and training

Georges-Louis Leclerc was born in Montbard, in the French region of Burgundy, on 7 September 1707, into a family of civil servants. His father, Benjamin François Leclerc, was a minor official in charge of the gabelle, the salt tax, and his mother, Anne-Christine Marlin, also came from a family of public servants. He was named after a maternal great-uncle, Georges Blaisot, a tax farmer for the Duke of Savoy in Sicily, who died childless in 1714 and left a considerable fortune to his godson.

With that inheritance his father acquired an estate that included the village of Buffon and moved the family to Dijon, where he obtained various offices and a seat in the local Parlement. From 1717 Georges attended the Jesuit college of Godrans, and from 1723 to 1726 he studied law at the University of Dijon, the usual preparation for a career in the civil service. In 1728 he left Dijon to study mathematics and medicine at the University of Angers.

Travels and first steps

At Angers, in 1730, he met Evelyn Pierrepont, the young English Duke of Kingston, who was making the Grand Tour. For a year and a half he travelled with him through southern France and parts of Italy with a large and expensive retinue. Persistent but undocumented rumours from this period mention duels, abductions and secret trips to England, and these should be treated with caution.

After his mother's death, and before his father's remarriage, he returned to Dijon in 1732 to secure his inheritance. He had added "de Buffon" to his name during the journey, and he bought back the village his father had sold. With a fortune of about 80,000 livres, then worth nearly 27 kilograms of gold, he settled in Paris to devote himself to science. There he mixed with Voltaire and other intellectuals and lodged in the Faubourg Saint-Germain with Gilles-François Boulduc, the king's chief apothecary.

Mathematics and the sciences of matter

His first reputation came from mathematics. In a paper on the game of heads or tails he brought differential and integral calculus into probability theory; the "Buffon's needle" problem bears his name. He was admitted to the French Academy of Sciences in 1734. At the request of the minister Maurepas he undertook long research on the mechanical properties of timber for shipbuilding. After testing more than a thousand small clear specimens, he concluded that their results could not be extrapolated to full-sized timbers, and he went on to test whole structural members.

Director of the Jardin du Roi

In 1739 he was appointed director of the Jardin du Roi in Paris, a post he held until his death. Under his direction the garden became a major research centre and museum. He enlarged it by buying adjoining land and acquired plants and zoological specimens from around the world. This work, which began with the cataloguing of the royal collections, turned most of his remaining forty-nine years towards natural history, divided between Paris and Montbard.

The Natural History

His principal work, the Histoire naturelle, générale et particulière, appeared between 1749 and 1788 in thirty-six volumes, with further volumes published after his death from his notes, Bernard de Lacépède being responsible for many of them. Buffon meant to cover the whole of natural knowledge as it then stood, but the work was finally confined to the animal and mineral kingdoms and, within the animal kingdom, to birds and quadrupeds. Detailed descriptions of many species were largely written by collaborators such as Daubenton, Guéneau de Montbeillard and Bexon, while Buffon kept for himself the broad overviews. His brilliant style made the work widely read by educated people across Europe, and it was translated into many languages. Its influence reached Diderot's Encyclopédie and later generations, notably Lamarck and Cuvier.

The early volumes caused a strong controversy. He questioned the usefulness of mathematics in natural history, criticised Linnaeus's taxonomy and set out a history of the Earth that bore little relation to the biblical account. The Faculty of Theology of the Sorbonne condemned them, and Buffon published a retraction, yet he went on issuing the same texts without substantial change.

Earth theory and the Epochs of Nature

His geological ideas first appeared in the Theory of the Earth (1744). He distinguished between theory, which should be confined to proven facts, and system, an unverifiable hypothesis about origins. At first he credited water with the formation of strata, an account known as Neptunism; from 1745 he added the action of fire, or Plutonism, and later acknowledged that fire was the chief agent of geological change.

His intellectual testament was Les Époques de la Nature (1778). He proposed seven stages: the formation of the molten Earth, the consolidation of the great mountain ranges, the flooding of the continents by the seas, the retreat of the waters, a tropical fauna that inhabited the north, the separation of the continents and finally the appearance of man. To reconcile this chronology with Genesis, he argued that the seven days of the account were these seven epochs and that the text should not be read literally. He is also credited with estimating the age of the Earth from experimental data, although Newton had done so earlier without publishing it.

Biology and ideas about living things

In embryology he defended an epigenetic theory against the preformationism then prevalent. He postulated primitive "organic molecules" which, united by intussusception during development, would make up living beings. In his Discourse on the Nature of Animals he distinguished between vegetative functions, carried out by internal organs, and animal functions, performed by the senses, the limbs and the nervous system, a distinction that Bichat and Cuvier later developed.

He accepted a gradual ordering of living beings, functional rather than morphological in character, and believed in the unity of the structural plan of vertebrates, which he explained as a unity of origin, though as a hypothesis. He rejected the objectivity of systematics, Linnaeus's especially, which he regarded as artificial, and proposed a concept of species close to the modern one, based on the persistence of characters and on the impossibility of fertile offspring between distinct species. He also formulated what came to be called Buffon's law, that regions with similar environments may host different flora and fauna, regarded as an antecedent of biogeography, and he suggested that species could have changed after dispersing from centres of creation.

Reception and legacy

Buffon was widely read and debated. His prestige as a writer won him admission to the French Academy in 1753, although it also gave ammunition to his critics; d'Alembert called him "the great phrase-monger". His marriage in 1752 to Marie-Françoise de Saint-Belin-Malain produced a son who survived childhood; she died in 1769. In 1772, when he fell seriously ill and the plan for his son to succeed him at the Jardin had become impracticable, the king raised his Burgundian estates to a county, so that Buffon and his son became counts. In 1782 he was elected a foreign honorary member of the American Academy of Arts and Sciences.

He died in Paris on 16 April 1788. During the Revolution his tomb was violated, and his son was guillotined in 1794. Ernst Mayr wrote that Buffon was "truly the father of all thought in natural history in the second half of the 18th century". He is credited as one of the first naturalists to recognise ecological succession, though the theology faculty of the Sorbonne forced him to recant his theories on geological history and animal evolution because they contradicted the biblical account of creation.