Augustine never discusses the question of the state's origin both directly and in detail. The fullest remarks on this theme occur in these two chapters of his De dvitate Dei, and, as we shall see, even these are not wholly centred on the problem with which we are concerned. Allusions and quotations by later writers, when debating our problem, are most frequently to these two chapters. They make a suitable focal point to our enquiry.

Chapter 14 of the De dvitate Dei begins with a statement about the ends which the two ‘cities’ pursue, the main theme under discussion in Book xix. ‘In the earthly city the use of temporal things is referred to the enjoyment of earthly peace; whereas in the heavenly city it is referred to the enjoyment of eternal peace.’ Augustine now goes on to expound what the peace is which is desired by all men. As he describes it, it is identical with what he has called ‘eternal peace’; this alone ultimately satisfies all human longings. He continues with an account of how man is to conduct himself so as to attain this eternal peace. He is to obey the two chief commandments of God: to love God and to love his neighbour as himself. The latter must include having consideration for one's fellow men, encouraging them to love God, and being prepared to be thus encouraged by others.

Augustine's ideas about the Roman Empire were the outcome of two debates. One was the long-sustained debate among Christians since the beginning about how to look upon the Empire in relation to the divine plan of salvation. The other was Augustine's debate with himself, the slow realisation of what was implied by his theology, the growth of reservations about contemporary enthusiasms for the victory of Christianity under the Theodosian establishment, all culminating in his final rejection of the attitudes which nourished this enthusiasm. The final spur to the re-thinking involved was given by the perplexity, both within and beyond the Christian community, provoked by the Sack of Rome in 410. Thus at every stage of their development, Augustine's ideas in this sphere unfold against a varied background of contemporary reflection.

It is otherwise when we consider his views on what might be called the fundamental questions of political theory: questions about human society and its institutions in general, and especially in relation to the ultimate purposes of human life; questions about political authority and obedience, about law and social order. The very concept of a ‘state’ is one in which we credit Augustine with an interest by extrapolating from the direction of his remarks about Rome; but such an extrapolation, though permissible as a logical inference, must be recognised to be a historical anachronism if read back into Augustine. On such topics a little ingenuity and considerable industry can provide a fair harvest of remarks scattered through the works of Christian Fathers and of secular literati.

This book is, in the first place, a historical study. It seeks to discover and to understand a slice of the past: the particular slice being the thought of St Augustine of Hippo on a particular cluster of themes. Its object is not to cover ground already adequately covered. Even in English alone, there are several good expositions of Augustine's political thought. Accordingly, much that falls within the field generally recognised as ‘political theory’ is here not dealt with at all, or only touched on lightly. I have, for instance, allowed myself only the briefest of discussions of law, and not considered such cognate themes of Augustine's reflection as property, justice or war. On the forms of government and on the right way to exercise its functions even the little that Augustine has to say has fallen outside my scope. On the other hand, much of the book is concerned with subjects which would not normally be found in an exposition of Augustine's political thought. My purpose has been to consider the fundamentals of the way in which Augustine conceived the social dimension of human, especially Christian, existence. This is why much of the book is concerned with themes such as Augustine's vision of history and of God's work in human history. Such discussions have at times landed me in considering even more distant topics, such as, for instance, Augustine's views on prophetic inspiration, or on youth and age.

The exploitation of dramatic contrasts has always been one of the favoured devices of rhetoric. Augustine shared a liking for it with his literary contemporaries. There was something about the cast of his mind, however, which made dramatic contrasts a more than normally apt means of expressing his ideas. The schemes in which he thought tended to organise themselves around two poles. The notion of the ‘two cities’ is only one of many paired conceptions at the foundations of his thought. The division of mankind into two categories is a theme which enters into Augustine's earliest reflection on the course of human history. In one of the earliest of his expositions of the six stages of history, Augustine divides the human race into two genera: ‘the crowd of the impious who bear the image of the earthly man’, and ‘the succession of men dedicated to the one God’. The duo genera hominum had a long and continuous history in his writings over the next quarter of a century.

In the course of the following decade the idea took more definite shape in his mind: the two ‘kinds’ of men were defined in terms of two communities they were said to belong to, and their opposition was stated in terms of the opposition of two ‘cities’, one of the impious, the other of the saints. By about 411, when he was writing the eleventh book of his great Commentary on Genesis, Augustine had formed the intention of devoting a work specifically to the ‘two cities’.

The controversies of more than half a century concerning Augustine's intellectual development have brought us to a clearer appreciation of the authority with which Augustine endowed the holy scriptures from the very first days of his conversion to Christianity. The works of his maturity and old age supply ample testimony to the growing submission of his mind to the auctoritas divinarum scripturarum unde mens nostra deviate non debet. Even in his thirties, however, the young Augustine, with his adventurous mind giving its assent to the Christian faith, shared this basic conviction with the simplest piety of traditional, popular Christianity. Life within the Christian community and pastoral responsibility only deepened the hold of the scripture on his mind. Not unnaturally, he came to devote some thought to its status as the word of God.

The first of the works in which he was brought face to face with questions concerning the inspiration of the scriptures is his De consensu evangelistarum, written in the first year or two of the fifth century. Hermann Sasse has seen in this work the beginnings of a new idea of inspiration. The language which Augustine uses here, speaking of the evangelists writing their stories on the basis of God's suggestio, Sasse remarks, certainly allows more scope to the free creative work of the human author than did the cruder image of God using the writer as a tool or dictating the words, so widely current in the earlier tradition.

If historiography is to be divided—as history used to be—into ‘periods’, the years of Saint Augustine's episcopate would mark an important watershed among them. Little more than twenty years lie between the publication of the last great work of classical historiography, that of Ammianus Marcellinus, and the Seven books of histories against the pagans by Orosius. In 395, when Ammianus, in all probability, had just completed his work, Augustine became bishop of Hippo. Orosius, the Spanish priest who had found his way to Hippo in his flight from the barbarian upheavals in his home province, wrote his work at Augustine's bidding, in the years 416–17. Ten books of his master's great work of historical apologetics, the City of God, were by now completed. Ammianus was not much read during the middle ages; Orosius, though he found few imitators, became one of the standard text-books. To contrast these two authors as ‘classical’ and ‘medieval’ or as ‘pagan’ and ‘Christian’ does not take us far. They share scarcely any assumptions about how history is to be written and what it is about. Ammianus wrote towards the end of a century of profound changes in the life of the Roman Empire, political, economic and social, as well as religious. The rate of change quickened towards the end of the century. A further crisis lay between the publication of his book and the writing of Orosius's. These were the years following the death of Theodosius I, the years which saw the division of the Empire between his young sons and the political troubles attendant on the eclipse of imperial power.

We look upon the past in the light of our experience of the present. The fears and hopes we find disclosed in our own world evoke their echoes from the past as it appears to us. In a mind that is historically conscious there is necessarily some relation between its experience of the present and its evaluation of the past. The dynamic rapport between past and present in such a mind is a two-way affair. The perspectives within which it grasps the past also help to determine the shape imposed upon the present. If there is any sense in speaking of a man's ‘historical experience’, it is his total experience in relation to the way he sees the past and the future.

Augustine saw past, present and future within the theological schemes we have noticed in the last chapter. According to his favourite sixfold division of history, the world was now in its old age. This is the ‘sixth age’, stretching from the coming of the Lord in the flesh to his return in glory at the end. This is the age in which ‘the exterior man—also referred to as the old man—is undergoing the decay of old age, while the interior man is renewed from day to day’. Senescence and renewal are the two poles of Augustine's representation of the present epoch. In this chapter we shall examine the extent to which this representation prompted Augustine to take up any specific attitude to his own time. Did the notion of a mundus senescens crystallise any sense of a world in full decay, tired of life and only waiting for its end?

Thirteenth-century scholastics were addicted to quoting statements of Augustine's, as of other sancti, as auctoritates in support of their opinions. The conventions of the scholastic employment of auctoritates are now tolerably well known. A modern scholar will not be surprised by frequent divergences between the meaning of such statements in their original setting and the meaning given them by one or other thirteenth-century theologian. Thirteenth-century theologians would have been even less worried by such divergences. Their analysis can, nevertheless, be illuminating. In this Appendix I examine the use made by a number of thirteenth-century writers of Augustine's statements about the origins and nature of political authority and subjection, mainly in the De civitate Dei, Book xix, Chapters 14 and 15. This is one of the points at which we should expect the impact of Aristotelian ideas to show itself most clearly on political thought. It is here that we may best test the validity of the rival claims that the impact of these ideas revolutionised medieval political thought or, alternatively, that they stood in direct continuity with traditional, patristic and especially Augustinian thought-forms.

A. J. Carlyle may serve as representing the more widely held view:

We have come to the end of our investigation of a complex strand of Augustine's reflection, that concerned with divine purpose in human history, with the function of politically organised society, and with the place of the Christian Church within it. Following Augustine's lead, we have adopted the term saeculum to refer to the realm to which this reflection refers. Our investigation has shown that as Augustine's thought in this sphere took shape, it lent itself less and less to interpretation in terms of a ‘theology of the Constantinian (or Theodosian) establishment’. It is, of course, plain that as a provincial bishop Augustine was nevertheless very much an ‘establishment’ figure. The conditions of the organised life of his Church and of bearing episcopal office in it would scarcely have allowed anything else. Even though, in the years following 410–11, Augustine lost his earlier enthusiasm about the alliance between the Roman Empire and the Catholic Church, he could hardly have renounced it in practice. Indeed, he went so far as to invoke this alliance repeatedly, especially where coercing schismatics or heretics was concerned. In terms of his theology of coercion, conceived as an activity of the Church and as an exercise of pastoral care, Augustine could take such an attitude without dishonesty. His practice accorded well with principles which had deep roots in his mind. In the last chapter we have tried to disengage these principles from a tangled context, and to indicate how Augustine could reconcile them with the dominant emphasis of his theology of the saeculum. We concluded that he could do so quite simply because for him coercion was an act of the Church, not of the state.

Towards the end of his life Augustine wrote a work he called the Retractationes of his writings: not ‘Retractions’, though in the course of the work he did, on occasion, retract some statements he had made and now thought ill-advised or mistaken; rather, ‘Reconsiderations’ in the light of new knowledge and, more important, new perspectives of thought. Let the reader's anxieties be allayed: I shall not ‘reconsider’ the original edition of this book, nor shall I offer, as did Augustine, itemised revisions of views I expressed. Rather, I avail myself of the opportunity afforded by a new edition, twenty years after completion of the work on the first, to indicate major shifts of emphasis.

The most important landmark for Augustinian studies has undoubtedly been the discovery by Johannes Divjak of thirty hitherto unknown letters forming part of the Augustinian corpus. Twenty-seven of them are from Augustine's pen; with one exception they all belong to the last fifteen years of Augustine's life. Several give a vivid insight into Augustine's practical concerns as a bishop: his worries about the activities of slave-traders, anxieties about clergymen who fall short of expectations, about threats to rights of asylum, and so forth – practical matters, for the most part. If the doctrinal content of these letters is insufficient to add anything of substance to what we have long known, they do nevertheless illustrate afresh the seriousness of Augustine's pastoral charity, shading imperceptibly into concern about the order and stability of his society. At the end of Chapter 4 I touched on the roots of this.

For Augustine the institutions and the life of politically organised society were irretrievably infected with man's sin. Human society could not heal the dislocation nor bridge the gulf between the ineradicable tensions of this life and the peace of the heavenly city. The depth of this gulf became ever more apparent to Augustine in the course of the Pelagian controversy. Though created good, all men are born in sin; to what we inherit, we add what we do. In sum, the world is evil—but for its redemption by Christ. His coming has created another world, where division is healed, multiplicity restored to unity and corruption to integrity. Humanity has ‘trickled apart’: let us rally, return to oneness, collect what has been scattered, restore what has been broken. The reconciled world is the Church: mundus reconciliatus Ecclesia, as Augustine said in one of his finest sermons on this favourite theme of his. This commonplace of Western theology discloses the richness of its meaning only in the context of Augustine's dialogue with a long history of reflection on the Church in its relation to the ‘world’, especially in Africa.

Augustine belonged to two very different worlds. In Rome and, especially, in the Milan of Ambrose, he encountered a cosmopolitan Church, wielding wide influence over emperors and officials, occupying a place of leadership in society, confident of its power to absorb, mould and transform it. This image of the Church cast a spell over his mind which had some power even after he had come to build his conception of the Church on different foundations. On his return to Africa, however, Augustine encountered an ecclesiology which had become dominated by a very different tradition.

To reconstruct the mind of a writer from his works is an activity in some ways very like formulating a hypothesis, working out its implications, and testing it by continual reference back to the texts. So far this procedure in the first five chapters of this study has yielded a remarkably consistent reconstruction of Augustine's reflection on history, society and the Church. The strands of his thought on these related subjects, always closely interwoven, produced a single, coherent body as it matured. At the risk of representing Augustine as a precursor of modern ‘secularist’ theology, it is not out of place to describe his mature thought in this sphere as a synthesis of three themes: first, the secularisation of history, in the sense that all history outside the scriptural canon was seen as homogeneous and, in terms of ultimate significance, ambivalent (Chapters 1 and 2); second, the secularisation of the Roman Empire (Chapters 2 and 3) and of the state and social institutions in general, in the sense that they had no immediate relation to ultimate purposes (Chapters 3 and 4); third, the secularisation of the Church in the sense that its social existence was conceived in sharp antithesis to an ‘otherworldly’ Church such as was envisaged by a theology of the Donatist type (Chapter 5). These three strands together constitute what we may call a theology of the saeculum. The saeculum for Augustine was the sphere of temporal realities in which the two ‘cities’ share an interest.