In a 2014 interview, Nick Onuf argued that IR has lost coherence as a field and should instead be considered “as a species of social relations and [to] abandon IR theory for social theory.” Were that to be the case, the work of Peter Berger would certainly contend for space at the top of the list of required reading.

Berger, who passed away late last month, is well known to constructivist (and sympathetic) scholars for his 1966 book co-authored with Thomas Luckmann The Social Construction of Reality. That book, named by the International Sociological Association as the fifth most influential book of the 20^th century, is arguably one of the central social theoretical foundations of constructivism as it has currently evolved. Its influence can be seen in the earliest constructivist works. Onuf engages it in his World of Our Making (though not in great depth). So does Wendt in Social Theory of International Politics. And, to complete the trinity, so does Kratochwil in Rules, Norms, and Decisions (though only in an endnote).

It is not just constructivists in IR who have been influenced by Berger’s work. According to Google Scholar, Social Construction of Reality, at ~46,000 citations, has more citations that Weber’s Economy and Society (~27,000). The book introduced an entire nomenclature for talking about the nature of the social world, not the least the idea that people constantly construct their social reality whether they are aware of it or not. Berger and Luckmann argue that scholars must be concerned with knowledge, practices, processes and institutions of society in total, rather than only the social elite that were the focus of much of sociological inquiry before them. With these arguments come other concepts that have now become commonplace—if contested. Such is the power of Social Construction of Reality that it has—like all great intellectual works—transformed revolutionary ideas into commonplace ones.

While Social Construction of Reality is certainly an important point of intersection between Berger’s lifelong scholasticism and IR, it is far from the only one. Indeed, Berger also laid the groundwork for the recent interest in IR with the role of religion. Most of Berger’s work focused on the role of religion in Western society. In the 1960s Berger was a leading exponent of secularization theory, even though in books like Rumors of Angels he deplored some of its effects. By the 1980s, however, he became one of the first prominent voices challenging the assumption that the world was becoming increasingly secular. Instead, religion was remerging – sometimes with explosive effects – across much of the globe, not only in Muslim world with the emergence of militant forms of political Islam, but also in the supposedly godless West with the rise and rapid spread of Evangelicals. Only recently have IR scholars realized the significance of this reality, though Berger of course published on the subject before most in IR were giving it much thought.

In his passing, the IR community has lost a great intellect whose work provides much of the foundation for our work—both constructivist and non-constructivist alike. For constructivists, the connection is obvious. Even for those who reject constructivism, Peter Berger’s work has been instrumental in forcing them to examine their underlying ontological and social theoretical assumptions. If, as Newton is reputed to have said, we see further because we are standing on the shoulders of giants, then Peter Berger’s carry more weight than most.