His 1990 book (updated and much improved in 2010, as noted here), Rome and the Eastern Churches is perhaps the most sober look at ecumenical relations, including the plight of Eastern Catholics in-between Roman Catholics and Orthodox. I demurred slightly from his conclusions about the "eschatological" nature of Orthodox-Catholic unity which I thought perhaps overly pessimistic, but perhaps not given where things stand today, not least with the Russians.
His recent biography of Adrian Fortescue, whom I discussed here, offers tantalizing glimpses into the rapier-witted scholar, whose droll and acerbic correspondence I really hope to see some day published in full.
His 1993 book, Byzantine Gospel, was the first in a very long series of books at the end of the last century and start of the present one to focus on Maximus the Confessor, about whom much has been published, as I have noted on here many times.
His 2005 book, Wisdom from Above: A Primer in the Theology of Father Sergei Bulgakov, bore a preface from another leading English scholar of Russian Orthodoxy, Rowan Williams.
Along the way he has also written books about iconography, liturgy, beauty, and aesthetics; and covered all those topics, and much else besides, in his 1999 book Christendom Awake, which calls for Orthodox-Catholic unity so that the former may help the latter by reintroducing to the weakened Western Church a more robust sense of monasticism, asceticism, and liturgical mysticism, inter alia.
As if the foregoing were not enough, he has also written a number of studies of the lives of such giants as Chesterton, Aquinas, and others, including Bulgakov, as noted above.
Now he has turned his attention to another outsized figure of Russian Orthodoxy in the 20th century, Vladimir Lossky, on whom Nichols has focused his latest book: Mystical Theologian: The Work of Vladimir Lossky (Gracewing, 2017).
Given the prolific prominence and astute judgments of the author, and given the equal but different prominence of the subject, Lossky, this is a book to which attention must be paid.
About this book we are told:
Vladimir Nikolaevich Lossky, born in 1903, was not only seminal in the development of Orthodox theology in its Diaspora after the Russian Revolution, and a major figure in twentieth-century European theological history, but also one of those whose work can inspire a serious Christian life. This book is not so much preoccupied by 'placing' Lossky within the world of patristic scholarship or the history of Russian religious thought, but rather, on Lossky's substantive spiritual teaching - and, accordingly, that of the teachers, especially ancient and mediaeval, he commended. Its principal intention is of communicating this teaching.
The title echoes Lossky's own in his best known book, The Mystical Theology of the Eastern Church, a work choc-A-bloc with doctrinal reflection. However it concentrates perhaps more on his final, posthumously published, lecture course, Theologie dogmatique. Born in Wilhelmine Germany, brought up in Tsarist Russia, educated at universities in St Petersburg, Prague and Paris, deeply influenced by early study of the writings of the mediaeval Latin West, and living and working in France, Vladimir Lossky was ideally placed to provide a link between Orthodoxy and the Christian West. To go deep into Lossky, cordial concern for the spiritual and intellectual concern for the propositional must walk hand in hand. The consequent initiation into the depths of divine revelation Lossky can supply will be likely to profit in both heart and mind anyone who hears his message and seeks in coherent fashion to put it into effect.