This remarkable passage helps us to understand why Rome has always possessed such authority and symbolic resonance within Western culture. Its institutions, for all their often tumultuous history, proved the most durable ever devised by a human society, especially if we consider that the eastern empire in Constantinople survived the fall of Rome for a thousand years. When order was re-established under Charlemagne after centuries of barbarian invasion, his new state was framed as a restoration of the Empire; under Charlemagne's Ottonian successors, after another interval of barbarian savagery, the Carolingian Empire became the Holy Roman Empire, enduring throughout the middle ages – for Dante it was the living successor of ancient Rome – and in effect until the Congress of Vienna two hundred years ago. Even after that, kaisers and tsars continued to use the name of Caesar as their title; and the Roman talent for administration lives on today in the hierarchical structure of the Catholic Church.

At the same time, the earlier history of Republican Rome inspired a parallel and different set of values: it was from this period of Roman history that the medieval, Renaissance, and modern worlds derived the paradigms and discourse of republican political organisation, of freedom, citizenry, elected offices, and senates as alternatives to feudalism and monarchy. From Renaissance Florence to the American War of Independence and even the bloodthirsty and chaotic French Revolution, the Roman Republic offered endless examples of civic pride, patriotism, self-sacrifice in war, and heroic resistance to tyranny. And yet Republican and Imperial values were never completely separate, and Napoleon, rising to power as a revolutionary general, made himself emperor in a carefully staged ceremony deliberately recalling the coronation of Charlemagne.

The Romans themselves could be almost equally ambivalent about their own values, especially under Augustus, whose regime attempted with some success to find a synthesis between the stability of a new authoritarian administration and the appeal to Republican values and institutions as the source of pristine Roman integrity. Even in earlier times, politicians and others frequently referred to the supposedly austere and disinterested values of olden times to justify new measures. Rome itself was constantly recycling and repackaging its own myths.

This is one of the points of Mary Beard's fascinating new book on Rome. Her method is reminiscent of recent revaluations of the Renaissance biographer Giorgio Vasari, whom modern historians tended to consider an uncritical compiler of unreliable tales about artists until a newer generation realised that these very stories were an invaluable window into the thought and culture of the time.

Beard's approach is similarly shaped by what we could consider a literary or narrative reading of primary texts, not simply as quarries for the extraction of more or less accurate facts, but also or even more importantly as sources of ideas and values which speak to us of what really mattered to the Romans at various points in their history. And if one reads a primary text in this way, even its myths, half-truths, and fabrications are transformed from disinformation or distraction into the precious raw material of cultural history.

Mary Beard

This is also what makes her book so readable, and in this sense an ideal introduction to the subject for the non-specialist as well as a fresh and thought-provoking survey even for scholars of the subject. It is typical of Beard's approach that she outlines the vivid and exemplary story of the struggle for plebeian rights as told by Roman historians – one of those episodes that inspired many later progressive theorists and politicians, including Gough Whitlam – before asking how accurate this account really was, and then considering the surviving archaeological data. This is not just more interesting than merely outlining the scanty and inconclusive evidence for what actually took place: the traditional story is also of vital importance as ideology that could be, and was, mobilised for political purposes.

Beard starts her book with one of the best-documented episodes in the history of Rome, the conspiracy of Catiline, for which we still possess Cicero's prosecution speeches as well as Sallust's history and the accounts of later Roman historians. For all this wealth of primary documents, however, it remains hard to be sure how serious a threat Catiline represented, what his motivations really were, and who constituted his supporters and more or less private army.

This episode also introduces us to the various ways in which the Romans would use their own traditions about the past to justify actions in the present. From this point, Beard ventures backwards to the foundation of Rome, uncovering ever more ambiguities, from the difficulty of connecting the story of Aeneas with that of Romulus and Remus to the remarkably ambivalent attitude of the later Romans to the period of the early kings: many of their most sacrosanct traditions went back to Numa Pompilius or Servius Tullius, and yet the ultimate overthrow of the monarchy and the foundation of the Republic was also a cornerstone of later Roman ideology. What we discover, as we proceed, is that the Romans were constantly writing and rewriting their own history, frequently projecting contemporary institutions into the past, and conversely justifying reforms on the grounds that they were really the restoration of immemorially ancient customs.

Beard is enormously erudite, yet she writes in a fluent and familiar style scattered with mildly anachronistic expressions which remind us that the Romans were people like ourselves. She follows the growth of a small town into a great city, the originally almost unintended and certainly unplanned extension of the empire and the eventual crisis of the Republic, brilliantly revealing the destabilising role of armies primarily loyal to great leaders like Sulla, Pompey, or Caesar, and the way that Augustus solved this problem through the simple though very expensive measure of military pension reform. She gives a memorable account of these great men, who so often paid for glory with ghastly ends, but she also sheds light on the lives of the poor, women, and slaves, and shows how institutions and legislation were constantly adapted to manage a society bigger, more ethnically and culturally diverse, and more complex than any before it.

Beard's book, though substantial, essentially concludes with the second century, the happy age of the Antonines with which Edward Gibbon begins his monumental Decline and Fall of the Roman Empire; so there is a sequel to be written, revisiting the catastrophe that divided our history, unlike that of China for example, into the two distinct periods of antiquity and modernity, so that the modern West has developed in a perpetually renewed emulation of, and critical reflection on, its own classical precursors.