The mathematician and the forger

The mathematician of the title is Chasles and the forger is Denis Vrain-Lucas. Chasles was an outstanding mathematician, famous both as a geometer and as an historian of mathematics. He became a professor at the Sorbonne in 1846 when he was 53 years old and he continued to produce important, highly original mathematics texts until the final years of his long life. He was elected a full member of the Académie des Sciences in 1851 and the work of the Academy became a major interest in his life. He gave much of his time to serving on various commissions of the Academy. He never married and his only interests outside his teaching, research, and work for the Academy, involved giving his time to serve various charities.

Vrain-Lucas was trained as a law clerk and, like Chasles, he was interested in history. By 1854 a passion which he had for collecting manuscripts of historical importance seems to have moved into a new phase when he began to forge documents. Lewis writes in the introduction to [1]:-
By 1854, the one-time respectable law clerk was a budding master at his new trade. Using old paper purloined from Paris' numerous libraries, and special, handmade inks, Lucas wrote his masterpieces ...

Over the next sixteen years, Vrain-Lucas would create tens of thousands of autographed forgeries, selling over 27,000 to one collector who was a distinguished member of the Academy of Sciences. Using his prodigious memory for historical details and the public reading rooms of the august libraries of Paris, Lucas penned thousands of letters supposedly autographed by Pascal, Galileo, Descartes, Newton, Rabelais, Louis XIV, and other luminaries of science, philosophy, royalty, and literature. And remarkably, he sold his handiwork for hundreds of thousands of francs ...
The whole episode of Chasles and Vrain-Lucas seems quite beyond comprehension but in order to get some understanding of how Chasles might have been taken in by the forgeries we should look briefly at the background to the content of the first letters which Chasles bought from him.

In the eighteenth century there were three major views of physics and two views of the solar system which were supported by leading scientists. Copernicus had proposed a sun centred system while Kepler had discovered that the planets revolved round the sun in ellipses with the sun at one focus. However this left a major question - what kept the planets in their orbits about the sun?

Leibniz, Descartes and Newton each developed theories of how matter interacted, with each providing a version of mechanics. Leibniz's mechanics was based essentially on what today is called kinetic energy, while that of Descartes was based on momentum. According to Descartes, the planets must be linked mechanically to the sun in order that there is a force keeping them in their orbits, so the solar system had to be filled with matter to provide this mechanical link. He proposed a system of vortices in this matter which held the planets in their orbits. Newton, on the other hand, proposed the idea of universal gravitation. Bodies attracted each other in a vacuum without any mechanical connection to transmit the attraction. Basically France championed Descartes, while England supported Newton, but eventually Newton's ideas triumphed while those of Descartes were discarded.

When Vrain-Lucas approached Chasles in 1861 offering to sell him letters between famous people from history, Chasles bought them eagerly and asked Vrain-Lucas if he could seek out more. Chasles was sold letters purporting to be between Pascal, Newton and Boyle, in which Pascal claimed that he, rather than Newton, had first put forward the idea of universal gravitation. It seemed that France rather than England would have the final victory.

It is easy to see why Chasles would have been so delighted with the letters that Vrain-Lucas showed him. He was a patriotic French man with a passionate interest in the history of science. Even so it is almost beyond belief that he could have been so naive, since Newton was only 19 years old when Pascal died, and about ten years old when the supposed letters were exchanged between Pascal, Newton and Boyle. If it is hard to understand how Chasles fell for these forgeries, it is even harder to understand how such an highly intelligent man fell for some of the other forgeries that Vrain-Lucas sold him. There were letters from Cleopatra to Julius Caesar, letters from Alexander the Great to Aristotle, letters to Lazarus from Mary Magdalen and letters from Lazarus to St Peter. Remarkably all these people wrote in French [1]:-
Lucas also made crude approximations of Carolingian script and archaic orthography, but his texts are all essentially in modern French.
In all Vrain-Lucas forged around 27,000 letters over a period of about 16 years. It was not easy money, for he spend most of every day working on his forgeries [1]:-
He would leave his house at eleven o'clock and lunched, sometimes at the Café Riche, when he had money, sometimes at a small restaurant, when money was lacking. All day he would work at the Imperial Library, and at night he would return to his house after having dined. He would not speak to anyone, and he went only to the house of M Chasles.
In 1867 Chasles approached the Académie des Sciences with his "proof" that Pascal had discovered the law of universal gravitation before Newton. There followed a period of vigorous debate and argument over whether the letters were genuine and during this time Chasles strongly defended his belief that the letters were genuine. Eves writes [2]:-
When Chasles disclosed to the French Académie des Sciences his theory of Pascal's priority to Newton, there was considerable scepticism. Chasles displayed some of his letters, and it was pointed out that the handwriting was not the same as that of letters which were indubitably Pascal's.
The debate raged on through 1868, with Chasles forced to name Vrain-Lucas as the person who had sold him the letters [2]:-
Various anachronisms appeared. Each was met by a new letter furnished by Lucas, in which the difficulties were explained away.
For example it was pointed out that Galileo was blind when he supposedly wrote some of the letters which Chasles had purchased from Vrain-Lucas. This "problem" was explained away by Vrain-Lucas who produced another letter in which Galileo writes that he is not blind, but that he is pretending to be blind. It is hard to imagine a serious academic debate reduced to what appears to be farce, yet with Chasles still apparently believing all the letters to be genuine.

In 1869 Vrain-Lucas was arrested and tried for forgery. Chasles had to give evidence at the trial during which it became public knowledge that he had purchased hundreds of letters from Vrain-Lucas supposedly written by figures such as Galileo, Cleopatra, Lazarus, Amerigo Vespucci, Charlemagne, St Jerome, Plato, Socrates and many others. Eves writes [2]:-
There were 175 letters from Pascal to Newton, 139 from Pascal to Galileo, and a large number written by Galileo. ... It is probably true that Chasles, in his ardour and enthusiasm, did not look at many of his 27 000 purchases.
All these, as we have noted, were written in French. It also emerged at the trial that Chasles had paid large sums of money for these letters:-
Whatever else impelled Lucas, money was a primary concern. From 1861 to 1869 Chasles paid Lucas between 140 000 and 150 000 francs for the false documents and for books to which Lucas had given spurious provenances.
Witnesses testified at the trial as to how Vrain-Lucas went about his deception. One witness was asked whether Vrain-Lucas could have made all these forgeries and whether he could have acted alone. The witness replied [1]:-
I reply affirmatively to the two questions. His initial studies were not extended very far, but he complemented his studies by reading and by great assiduousness in his work; I do not believe that he had accomplices. His chief stratagem was to assume an imaginary collection, assembled by a great person, at once rich and scholarly. With the calm and composure that you know he has, he simply told his story, and allowed the buyer to excite himself on his own: the result was thus to enhance the value of the treasures that he said he possessed. After the discovery of an ink that is unique to him, we think that his principal method consisted in browning the paper with a lamp to give it an air of antiquity. We have tried his methods, but we are obliged to confess that we have not succeeded so well as he.
In February 1870, the Correctional Tribunal of Paris sentenced Vrain-Lucas to two years in jail, a fine of 500 francs and the payment of all the costs.

Of course there remains the question of how Chasles, one of the most intelligent men in France and a respected historian, had been taken in with such unsophisticated forgeries. They certainly were unsophisticated, for it does not take an expert to know that Plato, Socrates, Cleopatra, and Lazarus would not have written in 18th century French. The mystery of Chasles' naivety has never been explained. One might wonder whether being age 68 when he was first approached by Vrain-Lucas in 1861, he might have been losing his faculties through old age. If this is so then he had not lost the ability to produce mathematics of the highest quality since his solution of the problem to determine the number of conics tangent to five given conics which he found in 1864 was remarkable, particularly as it corrected a previous incorrect solution by the outstanding mathematician Steiner. Again Chasles' Traité des sections coniques (1865) is a text of major importance, and he was undertaking this work throughout the period he was purchasing documents from Vrain-Lucas.

Some have suggested that Chasles was indeed an accomplice of Vrain-Lucas. This also seems extremely unlikely. One puzzle which might be relevant to this possibility is that although Chasles and others paid Vrain-Lucas large sums of money, and he seems to have had little opportunity to spend the money, yet at his trial Vrain-Lucas claimed that he had spent almost all the money he had received. One might argue that if Chasles were an accomplice then he would not have paid Vrain-Lucas the sums he claimed. Yet if he were an accomplice then surely Chasles was just as naive to believe that those in the Académie des Sciences and others would accept the unsophisticated forgeries as genuine. This seems even less likely since we now have to suppose that Chasles was both naive and a crook and nothing in his life would suggest that he was anything other than the most honest of men.

Perhaps then Chasles was just so patriotic, and so wanting to make the academic discovery of all time, that his desire for the letters to be genuine overcame his common sense. In fact rather than be an accomplice, and therefore a common criminal, it seems more likely that Chasles was such an honest man, living a sheltered academic life away from the real world, that he accepted Vrain-Lucas simply as someone like himself with a passionate interest in history and scholarship. Perhaps as Eves suggests:-
... Chasles, in his ardour and enthusiasm, did not look at many of his 27 000 purchases.
These fascinating questions will never be answered. Do you believe that a mathematician could be a genius at his subject yet so out of touch with reality that he appears unbelievably naive?

References (show)

  1. H Bordier and E Mabille, Une Fabrique de Faux Autographes, Ou Recit de L'Affaire Vrain Lucas (Paris 1870).
  2. H Eves, In mathematical circles (1969), 39-40.
  3. J Rosenblum (trs.), Prince of Forgers (1998). [English translation of [H Bordier and E Mabille, Une Fabrique de Faux Autographes, Ou Recit de L'Affaire Vrain Lucas (Paris 1870)." href="#reference-1">1]].

Written by J J O'Connor and E F Robertson
Last Update April 2003