This, in the Platonic school, was how the end of the Middle Ages looked.
All his older philosophical writings deal with the problem of certainty, He wanted to overcome the skeptical philosophy; he wanted certainty. This is another element in his thinking. It is very important, again, because it presupposed the negative end of the Greek development. The Greek heroic attempt to build a world on the basis of philosophical reason came to an end in terms of a catastrophe which we usually call skepticism. This was the end of the Greek thinking. The end of the Greek development to create a new world of thinking in terms of reason was skepticism.
The heroic attempt of the Greek philosophers (after the archaic traditions had fallen down) to create a new world in terms of a doctrine of essences (Plato, the Stoics), came to an end in terms of skepticism. On this basis the emphasis on revelation must be understood. The negative end of the development of Greek philosophy, namely skepticism, is the negative presupposition for the way in which Christianity received the idea of revelation. Skepticism is very often the negative basis for a doctrine of revelation. Those people who emphasize revelation in the most absurd supernaturalistic terms are those who enjoy being skeptical about everything.
Skepticism and dogmatism about revelation are correlate. And the way in which Christianity emphasized revelation in the earlier period and almost up to the Renaissance, is based on the tremendous shock Western mankind experienced when all the attempts of the Greek philosophers to bring certainty proved to be in vain. And this proof was given by the skeptical philosophers, which permeated all schools at that time.
Secondly, this skepticism gave rise to something else, namely to the new doctrine of knowledge, to the new epistemology, which Augustine created and which starts with the inner man instead of the experience of the external world. The skepticism, which was the end of all attempts to build a world in the objective realm, in the realm of things and objects, had the consequence that Augustine was thrown into himself to find the place of truth there, instead of outside. So we have two consequences of his participation in skepticism: the one is that he accepted revelation, and the other that insofar as he tried to find certainty as a philosopher, he tried to find it in the innermost center of his soul – in the subject himself.
Augustine stands between skepticism and the new authority, that of the Church, as Plato stood between the old authority and the beginning of skepticism. Here again we have the end of the archaic period in Plato and the beginning of a new archaic period in Augustine.
The fifth point: the liberation from skepticism in the philosophical realm was produced by his Neoplatonic period. While skepticism was the one end of Greek thinking, Neoplatonism was the other end. Skepticism was the negative, Neoplatonism the mystical, way in which Greek philosophy came to 1ts finish.