It has never been part of the argument of this book that Christians did not attempt to use rational means of discovering theological truths. 1 The problem was rather that reason is only of limited use in finding such truths. Any rational argument must begin with axioms, foundations from which an argument can progress, and proceed to conclusions on which all concur. Pythagoras’ theorem starts from a right-angled triangle—the important point being that any conceivable right-angle triangle can serve as the “axiom” from which the theorem is proved—and ends with a proof which is logically irrefutable at any time or in any place. This is the essence of mathematical logic. Similarly, empirical evidence serves as axioms from which inductive proofs are made, although the empirical evidence which exists will always be provisional.
So where are the axioms from which theology can progress? Attempts by Thomas Aquinas and others to provide self-evident principles from which logical argument about the nature of God could progress collapsed as soon as it became clear (in the Enlightenment, for example) that there was no agreement about what these principles might be (as there had to be if they were “self-evident”!). One can talk of the revelation of God, but, as the Montanists showed, anyone can claim to have received a revelation from God, and there is virtually no way of assessing what is a valid or invalid revelation. In practice, revelation does not prove susceptible to reason because there is no way through which it can be assessed by reasoning minds. The result is that in the churches there was soon a battle for control over what counted as revelation, and the Montanists were among the casualties. The scriptures are often cited by theologians as the primary source of “axioms.” However, when one puts together the Gospels, the letters of Paul, the Book of Revelation and the Old Testament, there is no sense of a coherent “axiomatic” basis on which to build theological truths. As any study of, say, the Arian dispute shows, the different sides to the conflict drew on different texts to “support” their argument. Again the churches had eventually to assume control of how scripture was to be interpreted, in effect so that interpretations never conflicted with what became established as orthodoxy. Even Thomas Aquinas, one of Europe’s most outstanding champions of rational thought, had to suspend reason when it conflicted with orthodoxy.
So the point being made here is not that the Christians did not attempt to use reason but they could never reach agreed truths, any more than there could be, in practice, an agreed formulation of what is meant by Plato’s “the Good.” The evidence of Christian disputes shows conclusively that reason failed in achieving any kind of consensus, and, in fact, like other spiritual movements in the ancient world, Christianity splintered as it settled into different cultural and philosophical niches across the empire. The important question to answer is why Christianity was different from other spiritual movements in the ancient world in insisting that Christians throughout the empire should adhere to a common authority. This was the aspect of Christianity which was truly revolutionary, even if the fact is often overlooked in histories of the church. The common adherence to the message of Christ, both in his teachings and in his death and resurrection (and the need to control Christ in face of the many other spiritual movements which appropriated him), provides much of the answer, but it also seems to have been important to define the boundaries of what it meant to be Christian in a society many of whose values Paul had told Christians they must reject. Christians did not have the distinguishing physical and cultural marks of Judaism; they had to create these marks and enforce them in the highly fluid spiritual world of the Greco-Roman empire. Crucial to the establishment of authority in the early church was the emergence of the bishop and the consolidation of his position within a hierarchy of bishoprics based on the doctrine of apostolic succession. Ultimately this, and not reasoned argument, was where authority rested. Even though the hierarchy remained a loose one, authority rested here and not on the fruits of reasoned argument.
Increasingly, the history of the early church is being written in terms of diversity rather than unity of belief. Most communities were remote from each other. The varied cultural and religious traditions which shaped local theologies—now more fully recognized with the ever growing number of early Christian inscriptions being found and published— coalesced with the lack of axiomatic foundations to make doctrinal certainty impossible. When the bishops of Rome adopted Latin rather than Greek for the western church in the fourth century, they distanced themselves from the ancient centres of Christianity and destroyed any chance of asserting their primacy over the Greek world. As we have seen, orthodoxy eventually had to be imposed from above.
What seems to have marked the turning point is Constantine’s appreciation that the authority of the bishops could be used in support of the empire. However, he failed to appreciate how intractable the doctrinal disputes between the bishops had become, and his hope of having the church as a united body brought into the structure of the state by patronage, tax exemptions and toleration soon proved to be a fantasy. “You [the bishops] do nothing but that which encourages discord and hatred and, to speak frankly, which leads to the destruction of the human race,” he fumed. Hence his initiative in calling the Council of Nicaea to define and enforce a common doctrine. The theological history of the fourth century is largely one of the emperors, under immense pressure from invaders, attempting to achieve a foundation of orthodoxy so that they could preserve a united society. The embattled Theodosius eventually enforced Nicene orthodoxy by imperial decree and then, unlike his predecessors, moved vigorously to crush those Christians and others who continued to oppose it. Here politics won over theology.
In short, the argument is first that despite attempts by Christians to use reason, it was not an appropriate way of finding theological truths. The frustrations which followed led to arguments becoming personal and bitter. The texts of a Jerome or an Athanasius are marked by invective at the expense of reasoned argument. This was not only deeply unfortunate for Christianity but became a major hindrance to a state which was hoping to use a docile church to support its authority. Hence the imposition of authority, an imposition which, backed by Christian suspicions of scientific argument, crushed all forms of reasoned thinking.
Why was the suppression of reasoned argument so important? Reason is a means of finding truths through deductive and inductive logic. These truths may be valuable in themselves in helping us understand who we are (the theory of evolution), but they have also, through medicine, for instance, transformed human life. We are free to apply the fruits of reasoned thought to some of our greatest needs, in many areas with enormous success. Yet built into a tradition of rational thought is the necessity for tolerance. It is the only way in which it can progress. Reason also provides external standards of truth, often, for instance, from empirical evidence. This helps take personal animosity out of debates in that disputes over the interpretation of external evidence are normally less abrasive than those between human beings struggling to assert or maintain their personal authority. History suggests that conflicts between religions tend to be more destructive than those between scientists! In this sense, the price to pay for the assumption that there can be doctrinal certainty has been a heavy one.
Philosophically, therefore, it becomes crucial to define the areas where certainty is possible and those where it is not. This was another of the intellectual achievements of the Greeks. Pace Plato, they understood that the nature of the divine, if such spiritual force exists, cannot be grasped when there is no external evidence for it. The troubles described in this book come not from the teachings of Jesus or from the nature of Christians themselves (though arguably one can trace them to Paul), but from the determination to make “certain” statements about God. Tragically, the pressures to do so, many of them politcal and economic, were intensified by the introduction of the concept of an afterlife, in which most would be punished eternally for failure to adhere to what was eventually decided to be orthodox. If there is no external standard by which one can define God, then figures who have the authority to define him for others have to be created and this authority given ideological support. This invariably means the suppression of freedom of independent thought. It was unfortunate that Christianity became embroiled in historical circumstances which made this such a dominant issue.
One important theme which has run through this book is the linking of belief in rational thought with a belief in free will. Because rationalism has in so many fields enriched humanity’s understanding of itself and improved human life, rationalists have every right to believe in further progress. Those who have decried the possibility of rational thought or denigrated it do seem to have a much more pessimistic view of human existence. That was why I preferred to end this book with Aquinas rather than Augustine! Yet at the same time we do have a spiritual and emotional nature, and without it rational thought in itself would be arid. It is a healthy balance between the two which seems the goal.2
In conclusion, it is worth asking why the political dimension to the making of Christian doctrine has been so successfully expunged from the history of the western churches. It is virtually ignored in most histories of Christianity. (The important role of the emperors and their successors has been more readily accepted by the Orthodox churches.) It is understandable, of course, that the churches wished to claim control over their own history, but the disappearance is also a symbol of Plato’s greatest triumph, the successful integration of his thought into Christian theology. Plato argued that his Forms were realities which existed eternally and independently of whether or not they were grasped by the reasoning mind at any historical moment. The context, the time or place or particular historical circumstances, in which orthodox doctrine (if it was given the same status as a Platonic Form) was formulated was immaterial. As we have seen, Eusebius assumes that doctrinal truth was known from the beginning of time and had to be protected from novelties introduced by heretics. The church councils were simply markers in the process of protecting the truth. So one could disregard the role of the emperor in calling or influencing the outcome of councils.
History still has to be rewritten in the west, but the process is complete by the time of Gregory the Great. His immediate concern was to establish his own authority over the remains of an empire in which traditional imperial authority had disintegrated. There was no one to prevent him from rewriting the history of Christian doctrine as if the emperors had never played a part in it, and so he did. Drawing on the precedents set by Ambrose, the popes were now assumed to have control over emperors, a reversal of the political realities of the fourth century. It is only recently that scholars have begun to appreciate the extent to which the emperors actually made, in the words of Hilary of Poitiers, the bishops their slaves. It is simplistic to talk of the Greek tradition of rational thought being suppressed by Christians. It makes more sense to argue that the suppression took place at the hands of a state supported by a church which it had itself politicized (and, in the process, removed from its roots in the Gospel teachings).
The history of Christianity is often presented as if it had a natural coherence. The evidence suggests that this is not true. The church of Constantine and his successors, embedded as it was in the stressed environment of the late empire, was radically different from that of earlier times. It was in this context that the suppression of rational thought took place, for reasons which I hope this book has made clear. Likewise, after the collapse of the empire, the medieval church in western Europe developed new roles and strategies to cope with a society in which a number of weaker political authorities (the early states of Europe) were emerging in competition with each other. The battle to defeat the classical intellectual tradition was, for the moment, a thing of the past, and the church could turn itself to new and different challenges. Gregory is the linchpin. There is no doubt that he is one of the greatest spiritual leaders the west has ever produced, not least in terms of his restoration of moderation and moral integrity to the Christian tradition after the obsessional ascetic narcissism and destructive invective of the fourth and fifth centuries.
I would reiterate the central theme of this book: that the Greek intellectual tradition was suppressed rather than simply faded away. My own feeling is that this is an important moment in European cultural history which has for all too long been neglected. Whether the explanations put forward in this book for the suppression are accepted or not, the reasons for the extinction of serious mathematical and scientific thinking in Europe for a thousand years surely deserve more attention than they have received.