Abstract
John Lewis Heilbron passed away on November 5, 2023, in Padua, after a brief illness; he was 89 years old. He was in Italy with his wife Alison (they married in 1995) to attend the XLIII annual conference of the Società Italiana di Storia della Fisica e dell’Astronomia (SISFA), where he gave a paper on Galileo’s Assayer on the fourth centenary of its publication. 1
A scholar of vast interests and exceptional learning, a master wordsmith with a rare ability to range with extreme competence and absolute proficiency from the Scientific Revolution to the 20th century, Heilbron was born in San Francisco on March 17, 1934, the son of Louis H. Heilbron (1907–2007) and Delphine Rosenblatt (1906–1993). After attending Lowell High School, he completed his education at the University of California, Berkeley, earning Bachelor’s (1955) and Master’s (1958) degrees in Physics and a doctorate in History (1964), with a dissertation titled ‘A History of the Problem of Atomic Structure from the Discovery of the Electron to the Beginning of Quantum Mechanics’, written under Thomas S. Kuhn. 2 It was with Kuhn that Heilbron, as assistant director, took part in the major project – promoted jointly by the American Physical Society and the American Philosophical Society – to collect materials useful in reconstructing the history of quantum physics, cataloguing all available primary sources and conducting dozens of interviews with key players (1961–1964). 3 The project took him to Copenhagen, where he learned Danish and interviewed, among others, Niels Bohr, who would remain the focus of his interests in the following decades.
After a few years in Philadelphia at the University of Pennsylvania, Heilbron returned to Berkeley in 1967, joining the faculty, as Kuhn’s successor, in the History Department, where he spent the remainder of his career. After twice declining an invitation to move to Princeton, he established and directed the Office for History of Science and Technology (1973–1994) at Berkeley and served as Vice-Chancellor (1990–1994), becoming professor emeritus in1994. Heilbron also held visiting positions at Cornell (1985–1991), California Institute of Technology (1995, 1997 and 2011), Yale (2001–2004) and Georg-August-Universität Göttingen (2005). After permanently moving to England, he became a senior research fellow at Worcester College of Oxford University and senior research associate at the Oxford Museum of History of Science (1996–2004). From 2012, he was research associate at Caltech.
A leading historian of physics of his generation, Heilbron was a driving force in the transformation of the history of science into an independent academic discipline, not only in the United States. Prodigiously productive, he authored more than 20 books, dozens of studies and collections of sources of fundamental importance to the history of science. His scholarly works received the discipline’s most prestigious awards, from the History of Science Society’s Sarton Medal (1993) and Pfizer Prize (2001, for The Sun in the Church: Cathedrals as Solar Observatories), to the Médaille Alexandre-Koyré of the Académie internationale d’histoire des sciences (2000) and the Pais Prize for the History of Physics from the American Physical Society (2006). A member of the Académie internationale d’histoire des sciences (1981), the Royal Swedish Academy of Sciences (1987), the American Academy of Arts and Sciences (1988) and the American Philosophical Society (1990), Heilbron received honorary doctorates from the universities of Bologna (1988), Pavia (2000), Uppsala (2000) and Yale (2011).
In this short obituary, we can only list his books on the history of physics: H. G. J. Moseley: The Life and Letters of an English Physicist, 1887-1915 (Berkeley, 1974); Electricity in the 17th and 18th Centuries: A Study of Early Modern Physics (Berkeley, 1979; reprinted with a new preface, New York, 1999); The Dilemmas of an Upright Man: Max Planck as Spokesman for German Science (Berkeley, 1986; second edition with a new Afterword, Cambridge, 2000; also translated into French, Italian, German, Korean, Japanese, Chinese and Hebrew); Lawrence and His Laboratory: Nuclear Science at Berkeley, 1931-1961, with Robert W. Seidel and Bruce R. Wheaton (Berkeley, 1981); and Lawrence and His Laboratory: A History of the Lawrence Berkeley Laboratory, with Seidel (Berkeley, 1989). More recently, Heilbron wrote for less-specialist readers books such as Rutherford and the Explosion of Atoms (New York, 2003); Love, Literature, and the Quantum Atom: Niels Bohr’s 1913 Trilogy Revisited, with Finn Aaserud (Oxford, 2013); and Quantum Drama, with Jim Baggott (Oxford, 2024). 4 Another truly remarkable work of a different kind is Geometry Civilized: History, Culture, and Technique (Oxford, 1998), which, based on Books I-IV and VI of Euclid’s Elements, presents a rigorous cultural and historical picture of the function of geometry in the natural and human world. 5
Turning to the history of astronomy, four main works immediately come to mind. The first, a 99-page introduction to Wayne Shumaker’s annotated translation of John Dee’s Aphoristic Introduction concerning Certain Outstanding Powers of Nature – John Dee on Astronomy: Propaedeumata Aphoristica (1558 and 1559) (Berkeley, 1978) – presents a detailed and sprightly appraisal of Dee’s reformed theory of astrology. It includes a technical analysis of the mathematics, optics and astronomy of the aphorisms, as well as a sketch of Dee’s intellectual career. Heilbron distinguishes between ‘hermetic astral magic’ and ‘traditional, rationalistic, computational, deterministic astrology’, and discusses the principal figures in the tradition of optical astrology to which Dee belonged: al-Kindi, Robert Grosseteste and Roger Bacon, who understood celestial influences in the quantifiable terms of optics. He also mentions several of Dee’s contemporaries, including Gerard Mercator, all of whom were interested in creating a scientifically solid astrology. Heilbron takes on the so-called ‘Yates thesis’ on the importance of mystical Platonizing mathematics in the transition from peripatetic to early modern science. He allows a possible role for hermeticism in promoting a union of mathematics and experiment, and in encouraging attention to extra-scholastic subjects, but holds that the magicians’ secrecy, obscurity, credulity and irrationalism were antithetical to the ideals of modern science. Heilbron acknowledges Dee’s considerable talent and learning, but is critical of the occult interests that took him ‘farther and farther away from applied mathematics’ (p. 99).
Another extraordinary biography – undoubtedly one of the most innovative, after those by Leonardo Olschki (1927) and Stillman Drake (1978) – is dedicated to Galileo (Oxford, 2010; second edition, 2012; translated into Italian and Japanese). Based on extensive research in primary and secondary literature, this book is the product of a long ‘immersion’ in Antonio Favaro’s National Edition of Galileo’s works, which, more than a century later, still retains its value and offers possibilities for new discoveries. Heilbron covers all aspects of Galileo’s life, including his interests in art, music and poetry, starting with his lectures on Dante’s Inferno (1587–1588), and provides an account of Galileo’s scientific work that is based on a detailed understanding of Galilean science, which he explains with great clarity, even resorting to the (typically Galilean) device of dialogue. Calling attention to previously overlooked evidence in Galileo’s correspondence, unpublished lectures and pseudonymous dialogues, Heilbron brings forth Galileo’s ever-growing interest in astronomy, showing his increasing efforts to provide quantitative support for the Copernican hypothesis, mathematically expressed and as remote from any occult or metaphysical reasoning as possible. No one since Drake has conducted such a thorough analysis of Galileo’s science, from the early Archimedean theorems on the centre of gravity of solids and the writings on motion and machines, through the experimental and theoretical investigations on accelerated motion and the parabolic trajectory of projectiles, to his telescopic discoveries, the hydrostatics of floating bodies, the controversies over sunspots (and, later, comets), to the arguments in favour of the Earth’s motions in the Dialogue of 1632, and the final exposition of mechanics in the Two New Sciences of 1638. The conflicts with the Church in 1616 and 1633 are presented in a dry and detached manner, and the volume closes with a wry look at the ‘myth’ that developed around Galileo in the four centuries after his death. 6
With The Sun in the Church: Cathedrals as Solar Observatories (Cambridge MA, 1999; translated into Italian and French) – undoubtedly his most important contribution to the history of astronomy – Heilbron aims at integrating and correcting the interpretation of Galileo’s abjuration, which, according to the received historiographical reconstruction, allegedly brought astronomy in Italy to its knees. In his eyes, the ‘conflict thesis’, which assumes a fundamental and inevitable antagonism between the authority of a dogma-bound church and the free inquiry of scientific research, ‘simply cannot be sustained’ (p. 20). The novelty of Heilbron’s position lies not so much in asserting that religion could act as a stimulus to astronomy (a claim now well established for both the Babylonian and Islamic contexts), or that ecclesiastical patronage encouraged science education, including astronomy, throughout the Middle Ages and the Renaissance, but rather in showing how significantly the Church promoted astronomy, gradually, although unwittingly, preparing for the acceptance of Copernican cosmology in the 17th and 18th centuries.
The title hints at productive relations between astronomy and the Roman Catholic Church during a period often presumed to mark their all-time low. In fact, Heilbron argues, the Galileo affair was a nothing but a disruption in the otherwise fruitful, centuries-long ecclesiastical patronage of astronomy, culminating in the ‘big science’ of the 17th- and 18th-century meridiane. The very same problem – that of placing Easter correctly in the calendar, involving reconciling lunar and solar calendars – was the main reason why scholars from the Renaissance onward punched small holes in churches to direct a beam of light towards a calibrated line on the floor, and kept mathematics alive in the Latin West during the Dark Ages and also conveyed a little exact information about the physical world. “Take away number from everything and everything will perish. Deprive our time of computus and blind ignorance will seize everything. Those who do not know how to calculate can not be distinguished from animals”. Thus our schoolmaster [Pseudo-Bede, in De computo dialogus]. (p. 35)
In contrast with most historians of the Scientific Revolution, who relegate the history of the computi to a few footnotes in the grand narrative of the creation of great theories, Heilbron turns those scattered footnotes into a richly illustrated, profoundly learned and wittingly told story, making it one of the most revealing episodes in early modern science. Not only does he bring additional and compelling evidence to a claim he repeatedly made throughout his works, regarding the Catholic Church as the single biggest patron of scientific activity in the early modern period, but convincingly argues that the strongest piece of empirical evidence in favour of the heliocentric theory came not from telescopic observations made by Galileo, but from naked-eye observations made in the mid-17th century by Jesuits Giambattista Riccioli and Francesco Maria Grimaldi, and their famous student Giovanni Domenico Cassini. Their cathedral-based measurements of the diameter of the sun’s image at apogee and perigee ruled in favour of Kepler and unequivocally against Ptolemy. Moreover, despite the prohibitions against Copernican theory in 1616 and the forced abjuration of Galileo in 1633, Catholic astronomers (again, principally Jesuits) understood, taught and often used the heliocentric systems of Copernicus and Kepler in their astronomical research. And, despite the huge quantity of ink poured to describe the destruction of the Aristotelian geocentric world view and the triumph of the Copernican (or Keplerian) heliocentric world view, several important research programmes in 17th- and 18th-century observational astronomy did not at all depend on one’s worldview. This ‘normal science’ activity, brilliantly carried out by astronomers, craftsmen and practitioners concerned more with precise measurement than with grand theoretical frameworks, made key contributions to astronomy, and indirectly to cosmology.
One of protagonists of The Sun in the Church was especially dear to Heilbron and later became the focus of his last published volume. The Incomparable Monsignor: Francesco Bianchini’s World of Science, History, and Court Intrigue (Oxford, 2022) is much more than a biography; it is a history of European science, culture, art and politics in the early modern age written through the lens of the life of the ‘incomparable’ but little-known (even in Italy) Francesco Bianchini (1667–1729) – archaeologist, historian, diplomat, informer, engineer and astronomer, designer and creator of the ‘double’ meridiana in the Basilica of Santa Maria degli Angeli e dei Martiri in Rome, considered by many to be the most beautiful sundial in the world. Heilbron devotes a full section of the book to the meridiana, highlighting previously overlooked details.
I must also mention Heilbron’s efforts as organizer and promoter of research projects, weaving together international networks of scholars who collaborated with him or trained with him. Over more than five decades, he helped promote and coordinate important publishing projects such as the Dictionary of Scientific Biography (New York, 1970–1990), the Macmillan Dictionary of the History of Science (London, 1981), the Oxford Companion to the History of Modern Science (New York, 2003) and the Storia della scienza, Vol. 5 (Il Settecento) and Vol. 8 (Il Novecento) (Rome, 2002 and 2004). Last, but certainly not least, he was from 1980 to 2007 editor-in-chief of Historical Studies in the Physical Sciences (from 1986 to 2007 called, Historical Studies in the Physical and Biological Sciences), steadfastly urging scholars to commit to high standards and generously helping them improve their works.
In more than seven decades of relentless, passionate and rigorous activity, John Heilbron transformed a discipline and marked the lives of many students, friends and collaborators who had the privilege and pleasure of working with him. 7 To them, he leaves the memory of his uncompromising dedication to intellectual work, carried through to his very last days. He made it clear that, no matter how very different our contributions were from his and no matter how unattainable his often seemed to us, we were all engaged in a fundamental and exciting activity worth devoting our lives to. All of us whose lives and work were touched by his breathtaking intellect and wit will miss him terribly.
I will always cherish the memory of his availability to support my research, his generosity in devoting time and energy to me, the confidence of his judgement. I think back – now, and during those last, painful few weeks in Padua – to the days of work at Caltech and Oxford, the long walks in Shilton, Pasadena and Trento, the visits to museums, the classical music concerts, the many conversations, ever stimulating and full of new ideas, the bright smile of his great intelligence. To borrow the words John himself used to bid farewell to his master, Thomas Kuhn: What I primarily owe him is not from the realm of ideas. Rather it is the experience of working with a man who cared more about arriving at truth than about winning arguments. I admired him most, that is, for the noble uses to which he put a distinguished mind.
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