We begin by returning to ancient Greece and exploring in particular how reason became established as an intellectual force in western culture. Then we can see how Christianity, under the influence of Paul's denunciation of Greek philosophy, began to create the barrier between science—and rational thought in general—and religion that appears to be unique to Christianity. Far from the rise of science challenging the concept of God (as is often assumed by protagonists in the debate) it was Christianity that actively challenged a well-established and sophisticated tradition of scientific thinking.The first seven chapters present a survey of events and ideas in the ancient world before the advent of Christianity. The classical period in Greece was followed by Hellenism after the conquests of Alexander; then came the establishment of the Roman empire with its absorption of many Greek ideas. All these periods were characterised by plenty of intellectual activity. Christianity was to bring about a major change, although not immediately. Freeman's book is intended to explain how this came about.
Paul, who was largely responsible for the development of Christianity as a religion in the Gentile world, rejected pagan philosophy, although this did not immediately abolish intellectual discussion within the Christian community. The crucial event came in the fourth century with Constantine's conversion. When his successors enshrined Christianity as the official religion of the empire this inevitably brought about major changes in how it evolved. In the early years Christianity was very diverse, with many different views of the nature of Christ and his relation to God. But Constantine and his successors wanted Christianity to be unified, as much for political as for theological reasons, and the result was an official Church position on doctrine and a consequent condemnation of dissenting views as 'heretical'.
Christian philosophy in the early centuries was written in Greek and was dominated by ideas derived from Plato. Western (Catholic) Christianity had little in the way of philosophy until the advent of Scholasticism in the twelfth century. But now it was Aristotle rather than Plato who provided the inspiration and intellectual guidance.
The dominant figure here is Thomas Aquinas, who is still central to Roman Catholic theology, although it was not always so. His Aristotelian "insistence on an underlying natural order of things (which appeared to deny God's power of miraculous intervention) and his respect for the body as the sustainer of the soul" were criticised. Some of his writings were formally condemned in Paris and Oxford and the Oxford condemnation does not seem to have ever been revoked. But later he was declared a saint and his pre-eminence was assured.
Thomas's voluminous writings mark the re-emergence of intellectual discussion within Christianity. He held that most religious beliefs, such as the existence of God, could be arrived at by reason, as his mentor Aristotle had demonstrated, although there were certain ideas, such as the Trinity, that could not be proved by argument and depended on revelation and faith. But there were relatively few of these.
Freeman contrasts Aquinas with Augustine, who placed faith above reason.
Augustine had made reason subservient to faith, even to the extent of suggesting that man's rational intellect had been corroded by original sin. Aquinas reverse that process, presenting reason as a gift of God, not a means of subverting God. A deeper understanding of the natural world leads only to greater conviction of the greatness of its creator.
There is a huge amount of information in this long book, and I'm not sure that the author's central argument always emerges as clearly from it as it might. Anyone who is primarily interested in understanding the development of Christianity in the early centuries would, I think, do better to read A New History of Early Christianity, and perhaps return to the present work to read the first few chapters and the conclusion. I think Freeman himself might agree with this. Writing about The Closing of the Western Mind in the review section on Amazon.com Freeman gave it only four stars instead of five "because since I wrote it I have come across a lot of new material which I think could improve its argument further."!