I have recently been reading about Augustine (354-430AD). He wrote:
- Just over 100 Books
- Over 250 Letters
- Over 350 Sermons
Western Latin theology of Augustine's time didn't have a particularly large number of influential theologians in the way that the Greek East at that time did. As a result, Augustine completely dominated the theological landscape of the period in the Western church and his writings were massively influential (the Greek East never read Augustine as they spoke a different language and no translations were made). Apparently virtually all theology in the Medieval period was done with reference to the writings of Augustine. Because he writings were so widely used, copies of 95% of them survive today.
What is most fascinating to me, as someone interested in the development of Christian doctrine, is how substantially Augustine's own ideas changed throughout his life. Scholars of Augustine talk about the theological views of the "early Augustine" as compared to the "later Augustine". It's the same person, but during the course of 30 years of writing on theology, studying the bible, and debating with others, Augustine's views slowly and substantially changed.
The theology of his earliest writings reflects the theology that he had been taught by other Christians. It matches the standard Christian doctrines of the pre-Augustinian period in virtually all respects. Most of the theology he held to thirty years later though was quite novel, having been drawn out from the bible and fleshed out by Augustine himself in the course of the various doctrinal arguments he got into. One of Augustine's works written at the very end of his life is titled "Retractions", and in that work Augustine surveys his previous books one by one and comments about how and in what ways he has since changed his mind and in what areas he would now disagree with his previous work.
In the Medieval period through to the Reformation within Western Christianity, virtually all sides claimed Augustine as advocating their position and attempted to prove it by quoting from his works. Since Augustine's works were inconsistent, in many cases two opposing sides could both find ample support for their positions from Augustine's works.
The amazing thing is, from the point of view of the history of doctrine, that Augustine managed to virtually single-handedly introduce so many novel ideas into Christian thought and make those ideas normative and shunt out much of what had before him been see as standard Christianity. Some examples:
* Probably most famous was Augustine's creation of the doctrine of predestination. Prior to Augustine all Christian writers vigorously defended the free will of man as one of the central points of Christian doctrine and predestination was opposed as pagan. The later Augustine advocated double-predestination, and Christians ever since have debated over how to balance God's sovereignty with free will.
* A related issue was Original Sin and the state of fallen man. Pre-Augustinian Christianity had taught that men were not guilty of Adam's sin and that after the fall they retained the image of God and the ability to do good. The later Augustine came to view humanity as a 'mass of sin', teaching a view later called Total Depravity, saying fallen humans were unable to do true good of their own accord. He also taught that people were born guilty before God due to their participation in Adam's sin.
* The early Augustine, like the Christians before him, held a moral exemplar view of the atonement. The later Augustine denied that moral exemplar was sufficient and insisted on the addition of Christus Victor and Satisfaction/Penal Substitution (in a rather bizarre embryonic form).
* The whole concept of "grace" as we are familiar with it today was fundamentally pioneered by Augustine. Previous Christians had typically seen grace as God's actions in the external world which influenced us by normal means. Augustine developed the concept of God's grace being internal - working inside of our heads to create psychological changes.
Augustine's efforts contributed many other ideas to Western Christianity. Ideas such as Purgatory, the importance and power of Baptism for salvation, the precise shape of the Western view of the Trinity (which differs to the Eastern view slightly). Augustine's views of justification were massively influential for subsequent Western Christianity. The strategy of double-justification which Augustine developed for systematizing the place of faith and works in salvation (whereby the believer is saved by their faith at the moment of conversion and then produces works throughout their Christian life which justify them at the final judgment) became standard in Roman Catholicism, and provided a starting point to be developed by the Protestant Reformers.
Scholars, of course, have fun in trying to outline and speculate about why it was that Augustine's views changed etc. It seems generally agreed by all that Augustine's idea of everyone being present in Adam at the time of his sin and thus everyone being guilty of it stemmed from a mistranslation of Romans 5:12 in the Latin bible he used. But is it coincidence that before converting to Christianity, Augustine was a Manichean who believed that "the nature of man can be corrupt to the point that his will is powerless to obey God's commands" (Chadwick, "The Early Church"), only to thirty years later start introducing that doctrine into Christianity?