The reasons for the apparent lack of Coptic theological works (at least in English) are, I suspect, many and complex. No doubt the Arab conquest caused a major hiatus in any such writing: sitting down to write theology while trying to avoid death seems an unlikely occupation. I am inclined to attribute a major influence to the influence of Protestant theology in the late 19th and early 20th centuries. However, there are obviously significant works which are simply not published, or not published in languages other than Arabic.
The only survey of Coptic theology in English (albeit very brief) of which I am aware is found in Otto Meinardus? two volume work, now edited and condensed into one volume: ?Two Thousand Years of Coptic Christianity? (American University in Cairo Press, Cairo, 1999:52-64).
He divides Coptic theology into:
1. Pre-Chacedonian theology
2. Post-Chalcedonian theology
3. The theology of the (Coptic) Middle Ages (by which he seems to mean the period from the 7th to the 18th centuries)
4. The theology of the 19th and 20th centuries.
However, some of the writings he describes as theological are in fact works on canon law (a survey of which he has already provided:45-52).
He rightly notes that little is known ?about the theological developments in Egypt immediately following the Arab conquest?. He also notes that the language of Coptic theology changed from Greek and Coptic to Arabic by the 10th and 11th centuries.
Meinardus does, however, provide an interesting account of a number of theological works from the period of the (Coptic) Middle Ages, virtually none of which would ever seem to have been published (at least in English). I would be delighted to be able to see a translation of, for example, Abu Ishaq?s ?Compendium of the Foundations of Religion? (c. 1260), or Afram Adad?s ?A Handbook of Religion? (c. late 19th century).
Meinardus cites works by a number of Coptic theologians in the 19th and early 20th century; I assume some of these may exist in Arabic versions. I would be fascinated to see, for example, Ibn Shuga?s ?Precious Pearls: Commentary on the Ecclesiastical Rites and Doctrines of the Faith? (1909), or Mikhail Mina?s ?A Systematic Theology? (3 volumes, 1933-1938), or yet the writings of Bishop Gregorius (whom Meinardus describes as ?the foremost theologian of the Coptic Church in the middle of he twentieth century?), including ?Spiritual Values in the Dogmas and Rituals of the Orthodox Church? (4 volumes, 1964-1966) or ?Christological Teachings?.
Not only do such works seem mysteriously absent from modern Coptic presses (again, at least in English) but so is any reference to them. An exception might be Fr Tadros Malaty?s ?The School of Alexandria?, a substantial two volume work (?Book One: Before Origen?, and ?Book Two: Origen?, seemingly self-published c. 1995). The production and layout are of poor quality, as is the English and the editing, but the work is a valiant and impressive attempt to deal with this topic from an insider?s perspective. With sound editing and referencing, it would be a major reference work. It is unclear whether the work is currently available, or has even been withdrawn (I was given my copies by Fr Malaty).
The closest I think I have come to a contemporary living Coptic theology was in working (with Deacon Brendan) in transcribing (and trying to render into good English) the course on ?Systematic Theology? given by the senior Coptic monk in Australia (who was also my teacher in the ?Forty Days?). He had been trained in the theological tradition of the monasteries and of Upper Egypt, and certainly seemed to have no patience with much of what was presented as Coptic theology. Unfortunately, he also held to the ancient practice of the oral transmission of tradition and was disinclined to (not that he had the time to) commit to writing. He once presented me with a fundamentalist Protestant enquirer, giving the simple instruction: ?Correct him where he is in error?! I remain unsure as to whether the enquirer or I was more surprised.