Now, the fuel is burned up. We shall not get fresh light by pumping in more oxygen. There has to be a renewal of the material on which critical reason goes to work. Augustine was a rational thinker not only in church history but also in the history of western civilization. All his great rational powers, however, could not extricate him from the disintegrating ruins of classical culture.
Reason can only work with the data that it is given.
The new vision could be developed by Augustine only because there were new data, because through Ambrose he was brought into living contact with the Church and with the Scriptures which embody the story by which the church lives. Revelation, the action of God himself in the events which the Church celebrates, gave him his new starting point. Thus, there was a new starting point for Augustine because God had acted and spoken in the events which form the substance of the Scriptures, and was still acting and speaking in and through the Church which accepted the Scriptures as God's word. With this, reason had new data to work on. A new possibility opened up for confident and hopeful living even in the darkness of the invading barbarism.