On stuff like hesychasm, theoria vs philosophy etc. and historical feuds, the theology behind it, and which tells you in a very easy to read manner the differences between the churches and which discusses which church is right? It should give basic overview on how mysticism and union with God which leads to understanding of divine truths is attained. I have a poor attention span so I need easy to read book that is not dry at all.
I am sure others can and already have provided you with some good theology works and explanations. However, I’d be more than happy to provide a list of historical works (books and articles), some of which others have already listed. The works I suggest do not simply cover actual controversies, but also the basic background of each side so that you might fully grasp their positions when they do come into controversy. I have listed them in the order I recommend reading them in:
Noble, Thomas F. X. “Michele Maccarrone on the Medieval Papacy.” Catholic Historical Review 80, no. 3 (1994): 518-533. **This is simply a review of a group of essays written only in Italian about the veneration of Saint Peter and the primacy of Peter. Noble summarizes their arguments and then offers his criticisms of possible short-comings, etc. **
Noble, Thomas F. X. “Morbidity and Vitality in the History of the Early Medieval Papacy.” The Catholic Historical Review 81, no. 4 (Oct. 1995), 505-540.
This is actually a historiography of papal history that is now 20 years old. Some progress has been made since Noble’s observations, but I think a lot of what he argued remains true to this day. I recommend you try reading this before reading any of the books, since it really gives you a good idea where historians stand on papal history, which is instrumental to your inquiry.
Dvornik, Francis. Byzantium and the Roman Primacy. New York: Fordham University Press, 1966. Corrected edition, 1979. ** This book is somewhat dated, but he provides some useful models to conceive of things.**
Meyendorff, John. Imperial Unity and Christian Division: The Church, 450-680 A.D. Crestwood, NY: St. Valdimir’s Seminary Press, 1992.
I have not read this one, but I have heard some positive remarks about it from historians on the period.
Runciman, Steven. The Eastern Schism: A Study of the Papacy and the Eastern Churches during the XIth and XIIth Cenuturies. Oxford: Clarendon Press, 1955.
Another dated work. This book was received rather lukewarmly because Runciman contended that the main cause of the division between Roman Catholicism and Eastern Orthodoxy was more cultural rather than doctrinal. Personally I disagree with his main thesis, but his focus is not unwarranted. Therefore, I still recommend it.
Noble, Thomas F. X. The Republic of St. Peter: The Birth of the Papal State, 680-825. Philadelphia: University of Pennsylvania Press, 1984.
This work doesn’t particularly deal with any specific controversy between the papacy and the Eastern churches. However, it does describe the beginnings of antagonisms between Rome and the Eastern Empire. Still, I highly recommend it because these issues are all related.
Dvornik, Francis. The Photian Schism: History and Legend. New York: Cambridge University Press, 1948. Reprinted 1970.
Some of what he says is pretty dated, but this book remains the fundamental and standard work on the issue for historians to this day.
Herrin, Judith. “The Pentarchy: Theory and Reality in the Ninth Century.” In Cristianità d’Occidente e cristianità d’Oriente (secoli VI-XI) : 24-30 aprile 2003. Spoleto, Italy: Settimane di studio della Fondazione Centro italiano di studi sull’Alto Medioevo, 2004. 591-628.
Some background info on all the authors. All of them are/were professional historians. Francis Dvornik was a Catholic priest as well. John Meyendorff was also a Orthodox theologian. Judith Herrin (recently retired) is a giant in Byzantine history. I do not know her religion. Steven Runciman was likely Anglican. He was a profound Byzantine historian. Thomas Noble is a Carolingian historian with a strong focus on papal history during the Carolingian period. I do not know his religion.
I am sorry to say, but Dvornik’s books can be pretty dry, but I think you should read them. Noble and Runciman are profound and excellent writers. Meyendorff I am not familiar with. And Judith Herrin’s writing is good too.
By no means is this all there is. However it’s a good place to start. As you might notice, I’ve shied away from providing many works on the Gregorian Reform Movement and the Great Schism of 1054. This is primarily because the understanding of the Gregorian Reform Movement has changed dramatically over the past 15 years or so of scholarship. Therefore, it would be overwhelming to jump into it. Not only that, but much of the recent work on it is incredible dry. For the meantime, I hope Runciman’s elegant prose can suffice for the 11th and 12th century controversies.
P.S. None of these books tell you which church is right. You shouldn’t let someone make such a decision for you. Instead, you should weigh the evidence yourself and decide.