Erwin N. Hiebert, professor of the History of Science, was born on May 27, 1919 in Waldheim, Saskatchewan, Canada, and grew up as the son of a Mennonite minister, Cornelius N. Hiebert, and Tina Harms, in a Mennonite community in Winnipeg. Although he never made much of his Mennonite background and convictions, the precepts of this radically egalitarian and rationalist Protestant sect colored his research and especially his teaching, to the great benefit of his many students. Hiebert was notably open-minded, advising many dissertations remote both in topic and approach to his own interests. He was also fair-minded, as the large number of women scholars whom he trained and supported in the teeth of prejudices on the part of his colleagues and profession testifies. Above all, he was a scholar, never happier than in his Widener study, immersed in the world of scientific and philosophical ideas.

Hiebert belonged to a generation of historians of science who came to the field as working scientists, often with a background in war research. He received his B.A. degree in Chemistry and Mathematics from Bethel College and his M.A. in Chemistry and Physics from the University of Kansas at Lawrence in 1943. His first job was as a research chemist with the Standard Oil Company of Indiana, under the jurisdiction of the University of Chicago Metallurgical Laboratories (where he earned a M.Sc. in Physical Chemistry in 1949) of the Manhattan Project.  He spent 1946-47 in Washington, D.C. as Assistant to the Chief of the Scientific Branch of the War Department. After a further stint at the University of Chicago, he moved to the University of Wisconsin at Madison, where he took his Ph.D. in the History of Science and Physical Chemistry in 1954.

In the aftermath of World War II, the Manhattan Project, and the deployment of atomic bombs in Hiroshima and Nagasaki, numerous scientists felt impelled to venture outside the confines of their research specialties to reflect more broadly on the implications of science in the atomic world.  Hiebert's first published book, The Impact of Atomic Energy (1961), examined these questions from an ethical and religious point of view. Like fellow chemist and Harvard president James Bryant Conant, Hiebert however also sought illumination in the history and philosophy of science, with the double aim of understanding the extraordinary conceptual innovations that had prepared the way for the meteoric rise of physics and chemistry in the twentieth century and also of preparing a democratic citizenry to make informed decisions in a techno-scientific age.

After leaving Madison, Hiebert taught at San Francisco State College (as an assistant professor, 1954), Harvard (as instructor in History of Science, 1955-7, visiting professor 1965), and finally returned to Madison in 1957, where he served as professor and chair (1960-5) of the Department of the History of Science until 1970, when he returned to Harvard as professor in the Department of the History of Science (chair, 1977-84), where he remained until his retirement in 1989.  These stations in an academic career were punctuated by excursions farther afield, some unsurprising in an academic vita (a Fulbright fellowship to the Max-Planck-Institut für Physik in Göttingen, in1954-5, a fellowship at the Institute for Advanced Studies in Princeton in 1961-2, and visiting professorships at the Universität Tübingen in 1965, the Zentrum für interdisziplinäre Forschung at the Universität Bielefeld in 1973, and the Hebrew University in 1981), others rather more so (a tour as scientist on a geophysical expedition to the Arctic in 1959 and as consultant for the University of Kabul in 1961). All his life, Erwin recounted stories of his summers as a youth threshing wheat on the North American plains with a certain wistfulness; despite his love of books and the library, a thirst for physical adventure never deserted him.

Hiebert's scholarship focused on three main areas: the history of chemistry and the physical sciences more broadly in the modern period; the relations between science and religion; and, dearest to his heart, the philosophy of science as seen through the eyes of major scientists, especially those active in the German-speaking world from c. 1850-1930. In his books on The Historical Roots of the Principle of the Conservation of Energy (1962) and The Conception of Thermodynamics in the Scientific Thought of Max and Planck (1968), as well as in articles on Walther Nernst, Ludwig Boltzmann, Hermann von Helmholtz, and Wilhelm Ostwald, Hiebert sought to understand how the stimulus of doing science inspired philosophical reflections on ontology and epistemology -- and in some cases, how the philosophy inspired the science. He had little patience with professional philosophy of science, untethered from the actual doing of science, especially science at the frontiers of knowledge (as opposed to toy examples from science textbooks). It is hard not to hear an echo of Erwin's own voice when he described Boltzmann's contempt for traditional philosophy and the latter's philosophy of science as "drawn mainly ... [from] the way in which he has been doing science all his life." Hiebert felt still closer to the Austrian physicist, psycho-physicist, and philosopher Mach, whose scientific experiments and historico-philosophical criticisms of scientific concepts (e.g. of Newtonian inertia) were pursued in tandem. The title of Hiebert's first historical book was a deliberate echo of Mach's first major historical work, Die Geschichte und die Wurzel des Satzes von der Erhaltung der Arbeit (1872); the quotation Hiebert chose to cite in his magisterial Dictionary of Scientific Biography article on Mach might as well have served as the motto of his own career as a historian of science: "Historical investigation not only promotes the understanding of that which now is, but also brings new possibilities before us, by showing that which exists to be in great measure conventional and accidental."

As a teacher, Erwin inspired admiration and affection but not because he was theatrically gifted. He was not a creature of large amphitheaters and often seemed faintly embarrassed behind the lectern. It was in seminars, with the texts spread out on the table, that he shone, reading with his students line by line, his enthusiasm for his subject matter infecting even the most phlegmatic students. The impression of the intensity with which he grappled with ideas and arguments, as well as the esprit de corps that welded the seminar into a community of inquiry, lingered long after the memory of specific passages from Helmholtz or Planck had faded.

Erwin and his wife Elfrieda made students warmly welcome in their home in Belmont, sometimes treating them to impromptu musical performances, Erwin playing the clarinet and Elfrieda the piano. In addition to her considerable accomplishments as a pianist, Elfrieda held a doctorate in musicology from the University of Wisconsin at Madison; like Erwin, she was a recipient of a Fulbright fellowship to Göttingen, the beginning of a lifelong engagement with the music of Beethoven and Brahms as performer and historian. Erwin's many women graduate students felt they owed a special debt to Elfrieda for her gentle resolve to continue as a scholar and pianist alongside her wholehearted commitment to her three children, Catherine, Margaret, and Thomas, as well as to their children thereafter. Above the mantelpiece of the Hiebert home in Belmont hung a reproduction of Rembrandt's The Mennonite Preacher Anslo and His Wife, a moving image of a companionate marriage. It surprised no one who knew them that Erwin died only a few months after Elfrieda, on November 19, 2012.