The assimilation of Plato and the Stoics will give rise to the works of Augustine of Hippo in which concepts originated in those, such as “eternal law”, “seminal reasons” and the “City of God”. Little was taken from Aristotle, skeptics and epicureans.
In general, the first thinkers who profess Christianity, had a rather negative view of philosophy. In some way, the discussions and contradictions between the different philosophical schools were judged as “charlatanery, or foolishness, or madness, or distention, or all in one piece”, as Taciano would say. Consequently, there is no more wisdom than the evangelical revelation that contradicts philosophy and surpasses reason: “The Son of God has died, completely credible, for it is a failure; he was buried and raised; true because it is impossible” Tertullian says.
But anyway, the “parents” will not hesitate to use Greek philosophy:
“What philosophers and poets have said about the immortality of the soul and the containment of celestial things, they have taken it from the prophets (of the Old Testament). Hence it seems that there are in all of them, seeds of truth that were not understood, because they contradict each other (...) We, on the other hand, have received the teaching of Christ, which is the Logos of whom the whole human race participates. And so, those who lived in coformity with the Logos, are Christians even when they were considered atheists (...) And from the Logos which spoke by the prophets, Plato took what he said about that God created the world transformed into matter.”
In this way, Justino justifies the assimilation of pagan philosophy, which set the problem of relating reason and faith.
Augustine of Hippo is the most important figure of Christian Patristics, collecting much of the philosophical tradition that precedes him has great influence on the history of Western thought. Fractly, his thinking is fluctuating and does not reach definite conclusions. Controversial and problematic, he intended to commit himself to his writings.
Manicheism brought together pagan and Christian elements offering an “enlightenment” of the soul that identified good with light. To a person like Augustine, tormented by moral struggle, Manicheism offered a solution to the problem of evil:
“It seemed to me that it was not us who sinned but that it was not what nature that sinned in us” Confessions, Augustine
On the other hand, Manichaean Dalism was narrowly materialistic. God, as the principle of good, was corporeal light:
When I wanted to think of God, I could not imagine but corporeal masses, because I thought that only what was a body could exist. From here I was born my belief that the substance of evil was also corporeal, a dark and shapeless mass, which could be heavy - and that (the Manicheans) called “earth” - or light and subtle as air - and imagined it as an evil mind that crawled the earth. And since I could not believe that the good god had failed to create a bad nature, I imagined that there were two corporeal masses, contrary and infinite, although the bad less than the good” - Confessions, Augustine
Manicheism, however, disappoints Augustine since proposing the simplicity of good before evil, it was not possible to make any progress.
Interest in skepticism marks a ruputra in his thought with Manichaeism: “I thought that academic philosophers had been more cautious in saying that all things should be doubted, that no verdaed can be understood by man” Confessions, Augustine
Plato and neoplatonism were well known in Milan, residence of the Imperial Court and center of culture. Ambrose, influential bishop, had drawn Augustine's attention. The bishop was knowledgeable of Platinum, Philo and Origins and practiced an allegorical interpretation of the biblical texts. For example, regarding the account of Genesis and the fall of the serpent, he interpreted man and woman as figures of delight and sensuality when understanding was carried away by the senses. Augustine was able to accept the biblical stories by seeing “not the letter that kills but the spirit that gives life”.
The writings of Plotinus also came to the hands of Augustine, translated by Mario Victorino, a neoplatonic converted to Christianity. The conception of God and soul as immaterial entities is a knowledge coming from such a source. Because almost all ancient philosophers had been materialistic except for Plato and the Neoplatonians. This sort of conversion of Augustine to neoplatonism, definitively introduces immaterialism into all subsequent philosophy.
The idea that only the grace of Christ can save man is taken from Paul. This doctrine on which he will return several times, is the core axis of his thinking and will mark the path of his departure from Manichaeism and his conversion to Christianity.
“Two loves fudged two cities. Self-love even the dereliction of God founded the eternal city. And the love of God even contempt of himself founded the heavenly city. The first glories in itself and the second in God. For he who seeks the glory of men and this glory has God, witness of conscience” Augustine, The City of God
This historical-political understanding that leads him to consider that love allows us to divide humanity into two cities can only be understood in the light of its theoretical background and, of course, the historical context in which it is inserted.
Indeed, the Roman Empire had sought an ideological justification in stoic philosophy - which had shown considerable flexibility and adaptation in this regard - and probably in the Jearachic view of the neoplatonic world conception. The official religion and also the oriental cults took care of divinizing the established order. Moreover, with Virgil, the foundation of Rome is linked to the gods themselves (see mythologian-Roman). Opposition arises with epicureism and cynicism that preach political absenteeism and position themselves in critics of the official religion. The monotheism and nationalist particularism of the Jews (the “chosen people”) is also becoming an area of conflict. There are also those who note that Christianity possessed a strong revolutionary burden by opposing the people of God to the Kingdom of Caesar, and in the book of Revelation the heavenly Jesursalen is opposed to Babylon, which is nothing but an allegory of Rome itself. The Empire represented the idea of a closed world in which divinity was part of a political community. The Christian conception stubbornly proclaimed the transcedence of God, altering the reassuring universe (as Touchard claims) that was closed upon itself.
In this context, it must be understood that the theme of “the two cities” was thus the essence of Christianity. It is not surprising that Tertullian, who defended the millenarianism, considered the two cities as antagonistic. Origins will say that Christians have two homelands (just as they possess body and soul) and that there would be a complementarity between them, in this way, the earthly city prepares for the ways of the city of god.
From the Edict of Milan, in 313, the opposition of the two cities is dimmed: Eusebius of Caesarea, who supports Conceinus, will say that the emperor receives the power of God and has as its mission to prepare the way of the Gospel: the two cities have begun the process of merging into one.