Quaeritur: 1. What are the most authoritative scholastic Manuals of Theology? I am basically looking for a list of great multi-volume compendia of exhaustive and thorough scholastic theology. Could you please list as many as you know, in order from best to less-good? It doesn't matter what language they are in, as long as they are thorough, meaty, etc... I know there are a few Summae and manualia written, but I don't know the names and authors.
2. What is the best compendium of scholastic theology next to St. Thomas' Summa? This is similar to the question above. I am just looking for a book similar to the Summa Theologica of St. Thomas, but written by a different author, who would have a little different spin on the subjects.
3. Do you know of any thorough compendia of theology written by Eastern Catholic theologians? If they were scholastic in style, that would be great, but I have heard that the East did not adopt scholasticism--but don't Eastern Catholics have theologians too? And if so, then what do they write? Do they not write anything thorough?
Respondeo: 1. Well it depends on what level of thomistic scholarship you are looking for. Obviously there are the commentaries on the Summa themselves, such as those of Cajetan, the Salamancan Fathers, Bañez, John of St. Thomas, etc. which are certainly much more detailed and thorough theology books, which truly advance Thomistic thought by posing new questions and making further distinctions. It is not without wonder that Leo XIII had Cajetan´s commentary on the Summa, attached to the Leonine edition of St. Thomas' Opera, and I can hardly recommend a more useful commentary. For a more extensive list, see the Ite ad Thomam Out-of-Print Library (ITOPL).
Otherwise if you are looking for more abbreviated "manuals" or Summae designed more often for undergraduate seminary training, there are obviously a million of them, and depending on the subject that you are researching, some prove more helpful than others. The Jesuit works of Billot, and the Spanish fathers, are very eminent, and more useful for their positive sources, and development in Ecclesiology. De Groot OP tries to develop a manual on ecclesiology according to the mind of St. Thomas, and is very useful.
However, for one who wants a more modern commentary on St. Thomas' work, which engages the history of subsequent debate up to modern times, I most highly recommend the works of the Rev. Garrigou-Lagrange, OP, who provides wonderful commentaries, truly imbued with the spirit and wisdom of his master, with sufficient detail while at the same time preserving a very unified vision of the whole of theology and its unity with the gift of wisdom, made perfect in charity and the practice of the spiritual life.
2. I would recommend the works of Rev. Garrigou Lagrange OP, or from the Jesuit school, Billot and the Spanish Jesuits' Sacrae Theoogiae Summa.
3. I am not aware of any, besides St. John Damascence's De fide orthodoxa, but this was written in the 8th Century, so its theology is not nearly as developed as that of Aquinas. Modern byzantine theologians tend to be more patristic in style, and less scholastic. Their theology did not develop much, as most all of them fell into schism for a thousand years, thus rejecting the development of Catholic dogma and, with it, the principles of Catholic theology, and most theological advancement. But I do recommend De fide orthodoxa: though by no means as sophisticated as those of the scholastics, his work is quite refreshing and uplifting. Maybe you could read this after you're done with one (or more) of the scholastic manuals.
I hope this helps.