Plotline: The story is set in south-western France around the turn of the twentieth century. A brilliant researcher is meticulously pouring over Leonardo DaVinci's manuscripts where he decodes subtle clues that lead him back to a little-known web of medieval priests and monks. This group had clearly ventured into areas they weren't supposed to. The researcher innocently sends news of his discoveries to exactly those people who were most threatened by the new knowledge. To their good fortune, he dies before his final manuscripts are published. The publication of these manuscripts is stopped under mysterious circumstances. The name of the medieval priest who was at the centre of the web would become the "name that dare not be mentioned" for 40 years. His own name, even though he had been considered the welcome new bright light before his discovery, would rarely be mentioned again. The secret of the Parisian doctors would remain hidden...if the researcher had not left behind a courageous daughter. Nothing was going to stop her from letting the world know about her fathers work. Not a global depression. Not a world war. Not thirty years of excuses from a publisher.
No, this isn't the plot of a pulp fiction novel or a Hollywood blockbuster. Because it isn't fiction. It actually happened. The researcher's name was Pierre Duhem. His daughter's name was Helene. Describing Duhem as "brilliant" is an understatement. It is extremely rare that a single individual can make historically significant contributions to three completely different disciplines, but that is what he did. Pierre Duhem was a world-renowned physicist from the late 19th and early 20th centuries. His main interest was in theoretical physics, and his work is still taught in university thermodynamics courses today . Physics wasn't his only forte, he also became involved in the philosophy of science, and one of his theorems, the Duhem-Quine Theorem, is still discussed by philosophers and economists today [_1_] . Later in life he turned his attention to the history of science. One can hardly think of a better candidate for a historian of science; extremely adept in both Math and Physics; meticulous in his research; knowledgeable about the culture of science from being a historically significant scientist and aware of the philosophical issues of science from being a historically significant philosopher of science.
Pierre Duhem's early historical work found an enthusiastic reception from the historians of science of the day. He wrote books on the history of mechanics and several on Leonardo da Vinci before attempting the encyclopedic 10-volume Systeme du Monde. The first volume, dealing with Greek science, was sent to George Sarton, the editor of Isis. Isis was the most reputable journal on the history of science at that time and George Sarton is commonly referred to as the father of the history of science. Duhem's work received a very positive review and George Sarton even let Duhem know that he was looking forward to the other volumes.
Isis, under George Sarton's editorship, did not review any more volumes of the Systeme du Monde. Pierre Duhem, renowned philosopher, theoretical physicist and meticulous researcher was rarely mentioned in the journal for the duration of George Sarton's editorship. The most important journal on the history of science seemed to put a cloak over Duhem's work. Something very dramatic must have happened. Had Duhem suddenly become sloppy in his scholarship? Not likely. Were the new volumes just rehashes of other people's work? Not likely as well; Duhem had always been an independent thinker. Too independent. He had discovered information that was at odds with the accepted interpretation of the history of science.
Pierre Duhem's meticulous nature had lead him to information about medieval physicists that demanded that a second look be taken at science in the middle ages. It also meant that the popular view of conflict between church and science might have to be revisited. Duhem had discovered that important advances in the science of mechanics had occured in the middle ages. And he could support his discoveries by quoting directly from passages in the original documents. In effect, he had discovered elements of "modern physics" in the middle ages. He even showed that Galileo had read their work [_2_] . This was a clear challenge to the status quo. The historians of the day looked upon the middle ages as a period where nothing of importance in the natural sciences was learned. Duhem's discoveries were even more challenging to George Sarton. George Sarton was a positivist who equated progress with science. And to him it was only science that could produce progress.
Pierre Duhem's road to being shunned by the academics of the day was innocent enough. His early investigations into the history of science were centered around the scientific works of Leonardo da Vinci. And it is clear that he started his investigations with the same historian bias that dominated most important historians of the day: that important scientific developments had not occurred in Christian Europe before daVinci [_3_] . Being meticulous, if Leonardo daVinci referred to a source in his works Duhem would spare no effort in tracking down information about that source. And if that source referred to another source, he would repeat the process. This eventually lead him from DaVinci to medieval physicists that were proposing ideas and concepts that had been attributed to more modern scientists such as Galileo and Newton. Duhem was probably better qualified to assess the physics of historical figures than any historian of science of his time or since, as he is a theoretical physicist of historical importance. His demonstration that important science had occurred in the middle ages was a direct challenge to the positivist historian bias that dominated at the time. Duhem may have been too naive to realize this.
The result of all Duhem's work was relative obscurity for about half a century. His publisher, Hermann et Cie, refused to publish the final volumes of his Systeme du Monde. The excuse given was financial hardship. The real reason why Duhem's work would not be published was divulged by an insider into the workings of the French scientific establishment; the head of the Institute d'Histoire des Sciences at the Sorbonne, Abel Rey. The reason that Duhem's work was not published was not financial concerns. Hermann et Cie was being pressured by very powerful anti-clerical elements in government and academe not to promise publication of his work. The information in the manuscripts was not something they wanted published; information that showed significant advances in the theoretical understanding of mechanics had occured well before the "Scientific Revolution" and during a time when the church was the central influence on society [_4_] . This was effectively censorship of the history of science by scientists. It is to Abel Rey's credit that he diligently supported Helene Duhem's 30-year fight against the censorship of her father's work since he too was anti-clerical.
Pierre Duhem died in 1916. Duhem had published documents detailing the work of Jean Buridan and a group of medieval thinkers (the Parisian doctors) who had developed an "impetus" theory. The "impetus" theory, attributed to Galileo, was considered a precursor to one of the most important scientific advances in the seventeenth century, Newton's concept of inertia. Duhem also presented documentary evidence that Galileo had read these medievals' work. He also showed how Domingo DeSoto had published a correct description the law of free fall, almost 75 years before Galileo did so. George Sarton would take the mantle of the most important historian of medieval science, studiously avoiding referencing Duhem's work. The most important journal in the history of science, Isis, with George Sarton as its editor, only sparsely referenced his work for the next 40 years (see Sarton-A Case for Bias). The final volumes of the Systeme du Monde were finally published in 1954, about 40 years after his death.