Problems with periodisation?

We break the past down into periods of time defined by cultural, political, social-economic or technological criteria because they offer a useful heuristic framework whereby historians can marshal the vast array of data of varying types and qualities at their disposal. Discussion of the merits and demerits of using a vocabulary of periodisation is of longstanding, nor is the idea that we can study the past in terms of periods characterised by a particular set of agreed criteria new. It was Petrarch who, in the fourteenth century, in comparing his own times with what had gone before— the ancient and classical world—described his century as a time of rebirth of ancient virtues and values after an intermediate period of social and moral chaos and decline, the Middle Ages. The notion that this ‘middle age’ represented a transitional phase between two other broadly-defined eras—the ancient and the modern—remains with us and is, indeed, and certainly throughout the ‘western’ world, the dominant mode of representing historical periods. Why is this particular descriptive framework so persistent? Chiefly, one might conclude, because it suits the concept of linear time and the fundamentally teleological mode of apprehension and perception that so characterises western thinking and philosophy (however much scientific thinking and physics in particular tells us that time is not linear). It thus helps people place themselves, however vaguely and arbitrarily, at a point along a chronological trajectory that makes sense of ‘now’ in contrast to ‘then’. But the problem of periodisation is analogous to the problems of the grammarian, who strives to understand the mechanics of a language and thus requires a heuristic device, in this case, a descriptive grammar. Just like a grammar, however, so a period, however defined, is also just that—a heuristic device—and imposes limits on thinking and analysis as much as it permits the asking of certain questions and liberates the analyst from previous inhibiting frameworks. On this basis, therefore, any characterisation of the historical past that generates a new heuristic framework that enables us—or compels us—to ask new or different questions is to be welcomed. As Garth Fowden comments at the outset of his important intervention, Peter Brown’s contribution in exploiting the notion of ‘late Antiquity’ as a way of understanding the threads of continuity from the ‘ancient’ to the ‘medieval’ in western Eurasia has more than demonstrated its heuristic value. For Brown, this was a holistic exercise, aimed at understanding the gradual transformations in a culture broadly speaking and over several centuries, in ideas and attitudes, perceptions and explanations of the world, in ‘ways of seeing’ and believing, and through a careful examination of the many different modalities of late ancient life and thought. It has been remarkably successful, and deservedly so, in challenging overly-simplifying notions of rupture and sudden change or catastrophe. Yet as has been pointed out, it has also generated a tendency to omit the sudden, the catastrophic, to re-read the relevant documents, whether textual or material-cultural,