The world of medieval history suffered a great loss on November 30 with the death of Professor Brian Tierney. Widely recognized as a leading scholar of medieval Western Christianity and how church law and institutions affected the broader culture of Europe, Tierney wrote widely but also deeply on topics ranging from the origins of papal infallibility to how religion shaped the development of constitutionalism.

Born in 1922, the formative experience for Tierney was, like for most of his generation, the Second World War. Serving in the Royal Air Force as a young officer and navigator, pleted something like 30 bombing missions over occupied Europe and Germany. After a break for further training, Tierney performed a further 60 missions in the RAF’s elite Pathfinder force. This unit was charged with doing the advanced targeting which enabled Allied bombers to hit strategic military and industrial sites deep inside Germany with ever increasing accuracy. “It gives you perspective,” Tierney once quietly remarked to me over drinks after a seminar sometimes in the early 2000s.

Tierney was, frankly, lucky to survive. The casualty rate suffered by British and American bombers during the early and middle stages of the Allied bombing offense against Germany was very high. For his efforts, he was awarded the Distinguished Flying Cross.

Tierney’s war service meant that he was able to attend Cambridge University in an accelerated program for veterans. He chose to do history. That was the beginning of a very long and distinguished academic career. After finishing his doctorate in 1951, Tierney took up a position at the Catholic University of America before moving to Cornell University in 1959.

I initially came to know Tierney through reading one of his most important works, The Idea of Natural Rights: Studies on Natural Rights, Natural Law, and Church Law 1150-1625 (1997). For a long time, the scholarly consensus held that the idea that individuals are bearers of rights was essentially a creation of modernity and the various Enlightenments. Rights, according to the British-Australian political theorist Kenneth Minogue, were “as modern as the bustion engine.”

Tierney’s book challenged that position. He marshalled extensive evidence to show that the notion of subjective rights first emerges in the writings of canon lawyers as early as the twelfth century and subsequently developed over time. Tierney wasn’t the first to make this case. Nor was it the first time he had touched on the topic. In an earlier work entitled Medieval Poor Law (1959), he had written about the rights of the poor in the Middle Ages. But Tierney’s Idea of Natural Rights outlined the argument in so much detail and with sustained attention to such a wide scope of theological, philosophical and legal sources that he effectively helped to shift the burden on proof to those who took a contrary view.

On the one occasion when I spoke to him about the topic, it became immediately clear that Tierney was not interested in, or animated by, mere ideology. He was invested in the history of ideas for the sake of knowledge of truth. Tierney followed where the evidence lead him and, when engaged in disputes with other scholars, avoided hyperbole, bombast, and flights of ego.

In these and many other ways, Tierney certainly fulfilled and lived the vocation of anyone who aspired to be a serious historian. Requiescat in pace.