查斯勒斯与卢卡斯的假信Michel Chasles and the forged autograph letters

59° Michel Chasles and the forged autograph letters. [The following true story, which is related to Item 58° above, is a mixture of the amusing, the pathetic, and the incredible. It is here told, with permission, in the words of Dean R. A. Rosenbaum, from his elegant narration in the Historically Speaking section of The Mathematics Teacher, May, 1959, pp. 365–366.]

Educators often consider the question of “transfer.” For example, does the study of mathematics instill habits of logical thought which carry over to the analysis of problems in other rational disciplines? It is of interest in this connection to examine the behavior of professional mathematicians, to see whether they exhibit notably logical qualities in the nonmathematical aspects of their lives. The spectacle of a mathematician acting in a markedly irrational manner fills most observers with unholy glee. No such spectacle can surpass that of Michel Chasles and the forged autograph letters.

Chasles was one of the foremost geometers of the nineteenth century. His Aperçu historique sur l'origine et le développement des méthodes en Géométrie…, published as a memoir of the Academy of Brussels in 1837, is an extraordinary achievement of synthesis and generalization which won him immediate recognition. He contributed many theorems to geometry, and the “principle of algebraic correspondence” is known by his name. Joseph Bertrand quotes what he refers to as an oft-repeated sentence, “All the geometers of Europe are disciples of M. Chasles.”

But Chasles was an especially ardent French patriot, and his nationalistic pride led to a debacle. When shown some letters, purportedly written by Pascal, in which the laws of gravitational attraction were set out, he eagerly bought them; here was proof of France’s priority to Newton’s England! A scholar and bibliophile with a comfortable income, Chasles continued to buy documents from one Vrain-Denis Lucas during the period 1861–69.

The details of his purchases seem incredible. He bought over 27,000 letters, for about 140,000 francs. There were 175 letters from Pascal to Newton, 139 from Pascal to Galileo, and large numbers written by Galileo. But Lucas provided ancient, nonmathematical letters as well. Included in Chasles’ purchases were six from Alexander the Great to Aristotle, one from Cleopatra to Caesar, one from Mary Magdalene to Lazarus, and one from Lazarus to St. Peter. Every letter was written on paper, and in French! It is probably true that Chasles, in his ardor and enthusiasm, did not look at many of his 27,000 purchases.

When Chasles disclosed to the French Academy of 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. Various anachronisms appeared. Each was met by a new letter furnished by Lucas, in which the difficulties were explained away. But after several years of controversy, Chasles had to acknowledge defeat. He exhibited his entire stock of 27,000 forged letters, and Lucas was sent to prison for two years.

Lucas’s defense at his trial was interesting. He maintained that he had done nothing wrong—that Chasles had really received his money’s worth, that the controversy and trial, which were widely reported, had stimulated in the public a healthy interest in history, that the debates in the Academy had been much more exciting than usual, and that he, himself, had acted through patriotic motives.

At the same time that one marvels at Chasles’ gullibility, one must be amazed by Lucas’s industry: to “antique” paper for 27,000 letters is itself quite a task! Lucas apparently had spent many hours each day in libraries, acquiring historical knowledge for his writings. Since he knew neither Greek nor Latin, he was severely handicapped in his work. According to J. A. Farrer (in his Literary Forgeries, Longmans, Green, and Co., 1907, Chap. xii), nothing is known of Lucas after his prison sentence; but Bertrand reports that Lucas served his time, returned to his “profession” after release, and was resentenced to three years as a recidivist, Chasles asking wryly, “Wouldn’t it have been better to sentence him to five years from the start?”

Apparently Chasles was greatly embarrassed by the affair, and Bertrand remarks that the man had suffered enough—the matter should be forgotten. But Farrer can’t resist giving a twist of the knife, which may well serve as a warning to all of us:

The logical incapacity that M. Chasles displayed throughout the contest subsequently waged over his supposed treasures shows conclusively how insignificant is the benefit conferred on the reasoning faculties by mathematical studies. The leading mathematician of his country showed himself incapable of reasoning better than a child.