Gavin Langmuir died on July 10, 2005, at his home in Stanford, California, of emphysema. A fellow of the Medieval Academy, he had taught at Stanford Unitersity from 1958 to 1993. Known especially for his work on medieval anti-semitism, he was the rare medievalist who was both public intellectual and academic historian.

Langmuir was born in Toronto on April 2, 1924. During World War II, Langmuir entered the Royal Highland Regiment of Canada as a lieutenant, fighting on the Siegfried Line, where he was wounded by shrapnel in early 1945 and barely escaped death. After the war, he received his BA from the University of Toronto in 1948. Intending to become a diplomat, he entered the graduate program at Harvard University in modern diplomatic history but changed to medieval history, writing his dissertation under Charles Taylor. His dissertation and early articles reflected the kind of constitutional history championed by Taylor, but with a more open-ended, less Germanistik approach and, above all, the kind of thoughtful argumentation and use of evidence that were his generation's greatest contribution to medieval scholarship in this country. In the course of conducting this research, Langmuir noted that the first acts traditionally regarded as Capetian "legislation" concerned Jews. What historians before the Holocaust had passed over without comment or notice, he could not. In 1960, he published "Judei nostri and the Beginning of Capetian Legislation" (Traditio 16:203–39). For the next 30 years he worked to understand why Jews had been so bound up with Christian self-image, when this had begun, when it had changed, and why. He produced a series of groundbreaking articles, including the first rigorous studies on the appearance and development of accusations of Jewish ritual murder. Increasingly aware of the dangers of historians' and sociologists' tendency to reify collectivities, he also realized that understanding the genesis of anti-semitism required understanding the psychological contradictions within individuals, which resulted in important studies of the anti-Jewish writings of Henry of Huntingdon and Peter the Venerable. Many of these articles were collected in Toward a Definition of Antisemitism (1990).

The articles were, as he would have said, a prolegomena to the culmination of his scholarship, History, Religion, and Antisemitism (1990). It is as much a work of theory as of history, as much about religion in general as medieval Christianity or anti-semitism in particular. Its hallmark is Langmuir's effort to make sense of religion in ways that apply the critical standards of the social sciences while remaining true to the experiences and beliefs of those who practice and believe in religions. The argument hinges on two key distinctions. The first is between "non-rational" and "irrational" beliefs. In effect, all religion is non-rational, in that it concerns the supernatural and transcendent that cannot be ascertained by empirical experience, but it is not necessarily irrational, because religion can easily conform to and usefully explain known experience. Irrational religious beliefs are those that are maintained in opposition to what individuals know and can know by the standards of their own societies. This distinction allowed him to substantiate in particularly rigorous terms the distinction between early Christian anti-Jewish beliefs, which regarded Jews and Christians as necessary adversaries, and anti-semitic fantasies that only appeared in the 13th century, with accusations of ritual murder and beliefs in menstruating Jewish men. A second distinction was between "religion" and "religiosity." The former includes beliefs and actions as enforced by whatever authority may be appropriate to the society at issue. The latter pertains to beliefs and actions of individuals, as they negotiate between the dictates of religion and their own unique experiences and needs. This distinction allowed Langmuir to argue that the change from anti-Judaism to anti-semitism did not grow out of Christianity as a religion but rather through the religiosity of certain key individuals, exemplified by the Cluniac Peter the Venerable. For Peter and his contemporaries, the problem was that the social, economic, and political changes of the 12th century created a society in which religion no longer guaranteed the security of their identities. The disparities between what they knew and what they had been taught created an intolerable doubt, which could only be eradicated by locating the source of all troubles in an "objective" enemy, relieving them of the impossible burden of questioning Christianity itself. The result was the kind of beliefs about Jews that became the justifying core of anti-semitism: that Jews conspired to commit cultic ritual murders of boys and host desecrations. The book was awarded the National Jewish Book Award in 1991.

Langmuir was an immensely talented graduate adviser, not only conscientious but also uncannily skilled in providing his students with the one recent book or newly edited source that would be sure to spark their own curiosity. But he never imposed his own interests on them. As a result, they have quite varied interests, and cannot be categorized in any way save for what they hope they share with him by example and affinity: a perceptible rebelliousness against received wisdom tempered by methodological discipline; a commitment to interdisciplinary research; and an abiding desire that medieval history be engaged with the world.

He is survived by his wife Nelee, his daughter Valerie Langmuir, and his step-daughters Jenny and Debra Wanner.

—Geoffrey Koziol
University of California at Berkeley

—James Given
University of California at Irvine