Stanley L Jaki's preface to Pierre Duhem's Les Origines de la Statique of early this century, is a masterpiece of its kind, worthy of the work it casts first light upon; but then Jaki has established himself among the truly discerning as the greatest living historian of science and to some extent shares two elements of Duhem's destiny — first, that both became historians from other professions, and both have suffered for daring to confront the 20^th century religion of materialism whose bible is science and whose proclaimed destiny is to master all of creation, especially to master and enslave man who has been reduced (in the minds of atheists) to a mere cypher in the laboratories of empirical data collecting. Duhem who is perhaps still the greatest physicist of the age came upon the history of science by accident. Thank God; for he alone blew away the post Renaissance myths that allowed every enemy of Christendom (if considered as the culture glowing out from Christianity) to trumpet one particular lie which has had the most profoundly baleful influence upon humanity since. That is the obscene nonsense that Christ brought stupidity upon the earth, that His followers had their heads so high in the clouds (of unreality it is also implied) that for well nigh 1,500 years every intellectual pursuit first embarked upon by the scholars of antiquity had been wrecked upon Pope, Priest and Bishop. The lie, to use another fashionable metaphor, was that Christendom represented The Sleep of Reason. Well Duhem nailed that lie forever, as I say; and although it may take much longer to silence the liars, honest men have been made aware that it is a lie and they will no longer tolerate it. And that is a wonderful thing for those finer intellectuals who have never allowed themselves to be influenced by prejudices fanned in pseudo science to become bigots against religion. Yet, before Duhem, the fair-minded could scarcely be blamed; for if Christendom's science were a truly proven folly why should not its Faith be irrational also? Indeed what is left to defend metaphysics or even philosophy if nothing may contradict the strident dogmas of materialism? So it had proved, for among the many tragedies of the post-Reformation, the least worthy turns out to have been the readiness of some excellent minds to accommodate those enthusiastic obfuscators of the Renaissance's true scientific provenance — which was firmly embedded in Christendom — the better to attack and harm the mother Church which they had made anathema. Alas for Christians, now aware of the dreadful ends to which that lie has reached, which is no less than the abolition of man if I may borrow the phrase from C. S. Lewis! How shall they whom we need as an army needs its crack units, defend us from a force that comes armed with their own old weaponry turned upon us to divide our ranks, or rather, to keep us divided while they encompass our entire destruction? Which brings me to Jaki. Is it not a pretty irony in this drama of the resurrection of physical truth, that the man affecting it is of the cloth; for Fr. Jaki came to the history of science from exactly the opposite direction. If Duhem had come to it from rigorous theoretical physics, from the natural, Jaki had, as it were, come, if not directly, then ultimately from the supernatural. The acid test which both survive is that the physicist describes reality as a scientist must, which is entirely within the frame of its physical causes — leaving such implications that arise from the impotence of material to explain itself to the metaphysician. On the other hand, the historian, despite his radiant Faith and awareness of God's sustaining creativity, lays out within the exact rules of his own discipline everything that must delight the reason of real historians. It is worth saying again that he too has to some extent suffered for his work and has never been allowed the full public recognition which it deserves. JB.

If ever a major study of the history of science should have acted like a sudden revolution it is this book, published in two volumes in 1905 and 1906 under the title, Les origines de Ia statique. Paris, the place of publication, and the Librairie scientifique A. Hermann that brought it out, could seem to be enough of a guarantee to prevent a very different outcome. Without prompting anyone, for some years yet, to follow up the revolutionary vistas which it opened up, Les origines de la statique certainly revolutionized Duhem’s remaining ten or so years. He became the single-handed discoverer of a vast new land of Western intellectual history. Half a century later it could still be stated about the suddenly proliferating studies in medieval science that they were so many commentaries on Duhem’s countless findings and observations.

Of course, in 1906, Paris and the intellectual world in general were mesmerized by Bergson’s Evolution créatrice, freshly off the press. It was meant to bring about a revolution. Bergson challenged head-on the leading dogma of the times, the idea of mechanistic evolution. He did so by noting, among other things, that to speak of vitalism was at least a roundabout recognition of scientific ignorance about a large number of facts concerning life-processes. He held high the idea of a "vital impetus passing through matter," and indeed through all matter or the universe, an impetus that could be detected only through intuitive knowledge.

Bergson was fully conscious of the challenge he posed to the rationalist heritage of the French Revolution as hatched by the Enlightenment. He was strangely unaware of a far more reliable and truly epoch-making meaning of the word impetus which was being brought back to light just at the time when the Evolution créatrice saw print. Bergson served thereby a proof of being a true child of the Enlightenment. Its champions were chiefly responsible for banishing from intellectual sight the light that invested, half a millennium earlier, the word impetus with a meaning that signalled a new epoch in science, in fact, its first genuine epoch.

A pivotal claim of the Enlightenment was dressed in glittering garb when, in the Evolution créatrice, Bergson spoke of Galileo’s inclined plane as the very instrument on which science descended from heaven to earth. Rarely was a secularist enshrinement more ill-timed. Worse, Bergson might have suspected the irony. He lived in that City of Light where literary and cultural news spread, then as now, with almost the speed of light. Bergson could hardly have failed to learn about the publication of Duhem’s Les origines de la statique in which the first appearance of a viable science on earth was tied to a means very different from Galileo’s inclined plane, whatever its great importance in the rise of modern physics.

Duhem’s name was not at all an unknown quantity to Bergson. Duhem is one of the very few modern authors quoted in Chapter 3 of the Evolution créatrice. Even more importantly, Bergson, in order to strengthen a principal strategy of his, referred there to Duhem’s Evolution de Ia mécanique, published in 1905. The strategy aimed at discrediting the mechanistic world view in which the world of matter, the only world, is a strictly determined machine with a fixed amount of energy. That Duhem had insisted on the various meanings of the word energy as used in physics was seized upon by Bergson as a scientific evidence that "the universe is not made, but is being made continually. It is growing, perhaps indefinitely, by the addition of new worlds." Logic exacted its due when Bergson concluded in 1932 his other widely read work, Les deux sources de Ia morale et de la religion, with the definition of the universe as a "machine for the making of gods."

Duhem could have hardly seen any profit in protesting Bergson’s use of his analysis of the notion of energy. There was little if any common ground between Duhem and Bergson, apart from their respective dislike, very different in nature and motivation, of mechanism as an all-purpose explanation. For Bergson the ultimate ground was an evolving universe as a supreme being. The author of Evolution créatrice denounced the idea of nothing and therefore had no use for the tenet, so dear to Duhem, of a creation out of nothing and in time. For Bergson, who took conscious time for the primary datum of knowledge, consciousness had to be eternal in a form however impersonal.

By 1906 Duhem had made a very different profession of faith in a classic essay of his, "Physique de croyant."¹ Had he known something of Thomist realism, Duhem would not have misunderstood Abel Rey’s charge that his philosophy of physics — being neither mechanistic, nor conceptualist — had to be the physics of a believer. For Rey, a positivist, it was inconceivable that direct knowledge of the reality of plain objects was plain knowledge, fully diffused with reason. Rey called that knowledge an act of faith.

Duhem, partly because of some fideistic touch in the French Catholic thought of his time, failed to see the danger latent in Rey’s use of the words, faith and believer, to his own theory of knowledge. Moreover, Duhem had interest in epistemology only inasmuch as he needed it for his theory of physics. Duhem took plain knowledge of plain facts for the very starting point of physics as well as of metaphysics already in 1894 when he began to reflect on the aim and structure of physical theory. But, so Duhem argued, since both physics and metaphysics made different uses of that very same basic knowledge, there could arise no real opposition between the two, let alone between physics and the tenets of Christian faith about supernatural realities and destiny. Such was the gist of Duhem’s essay, "Physique de croyant," which, apart from containing Duhem’s ringing profession of his Catholic faith, would by its general content have made useless any debate with the author of the Evolution créatrice. Much less would have it allowed for any meaningful debate with die-hard mechanists, positivists, and rationalists who set the intellectual tone in Duhem’s France.

At any rate, in 1906, Duhem had already been for two years in the grip of unsuspected cultural vistas of which he had caught the first glimpses in the Fall of 1903. Duhem himself tells the story, very briefly, in the introduction he wrote in 1905 to the first volume of this work. His original plan was to write in regular installments the history of statics for the Revue des questions scientifiques, the quarterly journal of Catholic scientists with headquarters in Brussels. They counted among their numbers dozens of members of the Académie des Sciences of Paris who found it most difficult to oppose the juggernaut of secularism in their own land.

Duhem conceived the plan of that history as a true child of the second part of the 19th century. There no one would have dreamt that there could be any science to look for between Archimedes and the immediate predecessors of Galileo. But unlike professional historians of the science of mechanics among his contemporaries, Duhem read with the truly meticulous eyes of a scientist the writings of those predecessors of Galileo as he jumped, in telling his story, from Archimedes to the second part of the 16th-century with some references to Leonardo at its beginning. Duhem was in for the greatest surprise of his intellectual life which resulted in a delay of his sending the third installment of his essays.

It was a sign of awareness of Duhem’s thorough scholarship that the delay was taken in the editorial offices of the Revue des questions scientifiques for an indication that Duhem might be on the track of some important finding. In fact, something of the nature of that finding was correctly guessed by the Pére Bosmans, who happened to visit the Pére Thirion, editor of the Revue, and wanted to see Duhem’s latest contribution. "I do not have it," the Pére Thirion replied, "Duhem has not finished it yet. He still has lots of reading to do. He promised me further chapters at the rate at which he writes them." "In that case," the Pére Bosmans replied, "I would not be surprised if his new readings would not convince Duhem to add complementary chapters to the period," whose history, the Pére Bosmans remarked (so it was reported by the Padre Thirion a few years after Duhem’s death in 1916), related to his own extensive studies of Stevin. The Pére Bosmans found that Stevin attributed great importance to Archimedes and Cardan, but ignored Leonardo in whom Duhem saw an important link in the story he was studying. But the Padre Bosmans also took the view that ‘if Stevin underwent Leonardo’s influence, he did so in any case only very indirectly. On the other hand I know of two small treatises ‘de ponderibus’, both attributed to Jordanus de Nemore. Duhem will end by finding them and I would be surprised if he were not to attribute some importance to them.

Jordanus de Nemore was indeed quickly found by Duhem, though not because during the preceding decade or so several historians of mathematics had noticed those treatises. Duhem’s lead to Jordanus de Nemore was his critical sense which prevented him from dismissing the charge of Ferrari, a contemporary of Tartaglia, that the latter was a plagiarizer in proposing the law of virtual velocities. Duhem then resolutely followed up some innocuous looking leads which, as he learned to read medieval Latin manuscripts, let him catch a glimpse not only of Jordanus but also of other members of the 14th-century Sorbonne, even more important for the history of science.

Fully aware of the fundamental importance of the law of virtual work in mechanics, Duhem quickly placed the remote origin of Newtonian physics in the Middle Ages. One could therefore only wish that Duhem had taken up Bergson’s use of his analysis of the notion of energy. In that case, he could have given a most revolutionary twist to Bergson’s reference to Galileo’s inclined plane as if that latter had been a secularist Jacob’s ladder from the scientific heaven and back. For by 1906, the year which also saw the publication of the first volume of Duhem’s Leonardo studies (Etudes sur Leonard de Vinci: Ceux qu ‘il a lus et ceux qui l’ont lu) Duhem had even discovered the impetus theory of Buridan. That theory, a substantial anticipation of Newton’s first law of inertial motion, was conceived by Buridan in an orthodox theological matrix. Buridan saw the instantaneous beginning of any inertial motion against the broader background of the impetus which the celestial bodies had received from the Creator "in the beginning" and is kept by them undiminished because they move in a frictionless space. In a sense, which Bergson and countless contemporaries of his would not have suspected, the science of Copernicus and later of Galileo and Newton was the fruit of contact, through Buridan’s vision, with the Heaven of biblical revelation.

In the history of the historiography of science — a history full of amateurism during the 19th century and professionally not robust until the mid-2Oth century — no discovery has more right to be called revolutionary than the one made and fully elaborated by Duhem. His discovery represented the strongest conceivable challenge to the broader ideology of the French Revolution. Its champions — purely intellectual as well as violently activist — never failed to claim that the Age of Reason, which they fondly equated with the age of Newtonian physics, could not have arisen had the Christian past of Europe, as epitomized in the Middle Ages, not first been thoroughly discredited.

Duhem was fully aware of the impact which that claim exercised on the higher instructional levels. It is still a basic claim of all those, and their number is legion in the academia, who resolutely try to shore up their scepticism, agnosticism, or plain materialism, with untiring references to exact science and its history. By taking a recourse to science, they run counter to the incisive analysis Duhem made of the aim and structure of physical theory. As to the facts of scientific history, it is no less true about them what a Baconian, if not Bacon himself, stated about empirical facts in general: Facts will ultimately prevail and we must be careful not to be found in opposition to them.

Those facts will not go away by the erection of specious stage screens. And most fashionable among them has been the idea of intellectual mutations. Originally a device proposed by Gaston Bachelard, it was made much of by Alexandre Koyré The essence of that device as articulated by him is not so much to deny the facts discovered by Duhem (although their slighting may be useful), but to claim that they were suddenly seen differently from the early 17th century on. Then the astronomical revolution running from Copernicus to Galileo would be realigned once more with the broader ideology of the French Revolution. This would also secure the role of science as the supreme safeguard of modern scientistic rationalism.

Had Koyré not been blinded by his Boehmean and Spinozean pantheism, he might have perceived that if there was an intellectual mutation in the history of science, it took place at its very medieval birth. Undoubtedly the shift is great from circular inertial motion (in which Galileo still fully believed) to a linear one as proposed by Descartes and later by Newton. Incomparably more fundamental and radical was the shift that involved as its starting and terminal points the following two ideas of motion: One was the idea of non-inertial motion (invariably held in all ancient cultures, including classical and Hellenistic Greece) in which there had to be continuous contact between the mover and the moved. The other rested on the concept of an impetus given in a single instantaneous act with no need for further contact between the mover and the moved. This latter kind of motion, fully inertial (be it still circular), originated, so the great medieval physico theological breakthrough stated, in an initial impetus tied to the creation of all out of nothing and in time. About this point, amply documented by Duhem, Koyré and his many admirers, pantheists or not, tried to be as taciturn as possible and in the name of scholarship.

In late October 1905, when Duhem wrote the preface to the second volume of this work, he had already on hand substantial evidence about the Christian theological matrix of the birth of modern science. Only with this in mind will one understand the unabashed homage he paid, as a historian of scientific ideas, to the guidance which a truly divine Providence exercises even in scientific history.

These are facts and indeed most crucial facts of intellectual history, represented by Duhem’s findings and by their reception, a rather reluctant one, to put it mildly. Those who want, in the name of "objective scholarship" to stay with the less crucial facts of that history, simply honor it in the breach. To recount them here would be superfluous. They can be found in my account² of the background, the origin, and reception of this book of Duhem in particular and of his work as a historian of science in general.

Here let emphasis be put once more on the revolutionary character of this work. It is revolutionary not in the trite sense given to that word, a sense unerringly perceived in the French phrase, plus ca change, plus ca reste la mème chose. Today when an era of drastic political revolutions reveals the triviality of once great revolutionary slogans, that French phrase should show an eery relevance. Academic circles still have to perceive the contradictory character of intricate discourses about scientific revolutions with an overarching structure to them. This they cannot possess if they are truly incommensurable.

With an eye on scientific history, Duhem held high in this book and elsewhere, the idea of a slow and continuous development. He did so in a manner very nuanced from the logical viewpoint and also very graphic at times. The opening paragraphs of the conclusion of the second volume of this book are more than a literary masterpiece. They also witness Duhem’s keen observation of nature. The scene, the apparent discontinuity of a river in the Larzac, which he painted with a marvelous choice of words, he also drew as a landscape painter: At any rate, Duhem as a logician had as little use for scientific revolutions as he, as a French patriot, had for the French Revolution. Not that he had not spoken of revolutions in science. But he never meant by them the kind of radical discontinuity which they are meant to convey for most historians and philosophers of science today, invariably forgetful of the duty to give precise definitions of the basic terms they use.

Duhem, who did not consider himself a historian of science, was one of the greatest of them ever. He studied the history of physics only because he wanted to achieve a better grasp of the conceptual foundations of theoretical mechanics. "I am a theoretical physicist and I will return to Paris only as such," he told his daughter around 1903 when some friends of his in Paris tried to obtain for him the chair of the history of science in the Collége de France. By then Duhem had been in exile from Paris for more than a decade and was to stay in exile, that is, in a provincial university (Bordeaux), until his untimely death in 1916 at the age of fifty-six.

The immediate cause of his death was the pain that seized him on hearing a defeatist note as France had just made her heroic stand at Verdun. His heart had for long been taxed by great personal and professional setbacks. His much beloved wife died in the summer of 1892 in trying to give birth to a son who had to be buried with her. During his first ten years in Bordeaux, where he arrived in 1894, after teaching for six years in Lille and one year in Rennes, he had been most unfairly treated by local agents of the Ministry of Public Instruction in Paris that faithfully observed the ukaze Marcelin Berthelot had issued in 1885: "This young man shall never teach in Paris." It was at Berthelot’s instigation that Duhem’s brilliant doctoral thesis, today a classic, on potential thermodynamics (which refuted a favorite brain-child of Berthelot) was rejected by the Sorbonne on rather flimsy grounds.

By September 14, 1916, when he collapsed, Duhem’s energies had been strained to the utmost by what may easily qualify as the greatest individual scholarly effort of modern times. In March 1913 he signed an extraordinary contract with Hermann in Paris, The contract called for the delivery by Duhern during each of the next ten years of about 800 handwritten pages, full of important historic texts to see print for the first time. By early September 1916 Duhem was proofreading the fourth volume of his famous Systéme du monde. The material of the fifth volume had already been sent to the publisher. Duhem left behind, in fully publishable form, the material for another five volumes. They did not see print until the 1950s. In fact they almost failed to see print at all.⁴ That this translation appears in English almost a full century after its publication is part of much the same discouraging story, a story that should make not a few heads hang in shame.

Why, one may ask, have professional historians of science not seized long ago the opportunity of making this great book available to the English speaking academic world? Has not that world been all too eager to have many and far less important foreign books available in English? Tellingly, the translators of this book are not professional historians of science. Indeed, it reflects the universality of Duhem’s mind that the three translators were attracted to him from diverse fields of speciality, one a classicist, one a scientist, one a Gallicist. Historians of science stand to them in great debt and should appreciate their thorough competence both in respect to the subject and the fine quality of Duhem’s style.

The appearance of this book in English translation almost a hundred years after the publication of the original is a witness to a more encouraging story as well. It is the story of the lasting value of genuine scholarly research and of historical truth. No one had a greater confidence in that story than Duhem did. To his researches in the history of physics one can apply with equal justification his motto, "being eternal, logic can be patient," expressive of his trust in the ultimate victory of a strictly logical physical theory. He used that motto with an eye on the momentary success of partly illogical physical theories. The fashionability of contempt for logic in trend-setting interpretations of the history of science would leave him undisturbed. The wealth of evidence set forth in this book is another proof of a point repeatedly noted about the rise of the idea of progress, be it scientific, and its prospects. If it is to be diffused with genuine confidence, it demands eyes focused on eternity. Stanley Jaki