One of the underlying assumptions of the authors is that the environment, including physical structures such as mountains and plains, and climatic conditions, provide the context for civilisational developments. They document the evidence for physiographic and climatic changes. These are then connected with the decline of the Harappan civilisation which is partially explained in terms of changes in river courses and decreasing rainfall. The authors suggest that this triggered off population movements into first, the upper Ganga-Yamuna doab, and subsequently to the south and east. This in turn provided the context for what is known as the second urbanisation, that of the Ganga Valley.
Defining civilisation or culture is notoriously problematic. The authors define cultural identities in terms of "deeply rooted patterns of thought, religious and philosophical attitudes, social behaviour, artistic expression, and a range of different but interrelated life-styles (p12)." More specifically, they understand the co-existence of diverse communities to be typical of South Asian culture from the prehistoric period onwards. Civilisation is conceptualised in terms of intensive agriculture, urbanism, increasing social complexity, and the use of writing.
The Indus Valley remains central to their discussion. The authors explore the nature of pre-Harappan settlements and argue for a gradual change from a rural to an urban setting, culminating in a century of rapid transformation (2600-2500 BC). They outline possible subsistence strategies and discuss changing settlement patterns, including regional variations. In doing so, they focus on specialised settlements as well as on the more familiar elements of town-planning. Possible systems of craft production and varieties of trading networks are delineated. The vexed question of the Harappan language(s) and script also attract attention, as do some of the more recent stimulating debates on the less tangible aspects of the civilisation, including political institutions, art and religion.
The treatment of the post-Harappan phase is the weakest link in the chain of analysis. The authors argue for a population shift and a gradual multi-wave intrusion of Indo-Aryan language speaking peoples. This is felt to have provided the stimulus for the Ganga Valley civilisation in particular and civilisational expansion into the rest of the subcontinent in general.
At one level, the argument is attractively neat, and even plausible. It seems to be supported by the fact that there are certain obvious commonalities between the Harap-pan and the Ganga Valley civilisation. However, a closer examination would reveal that many of these common features are found in other civilisations as well, and are not necessarily representative of genetic bonds between or amongst them.
Town planning provides an obvious example. Most of the major Harappan cities have a distinctive layout, dominated by a small, high citadel mound usually situated to the west of the larger lower town. While some early historic sites such as Sisupalgarh in Orissa show signs of planning, they do not correspond with the Harappan model. Nor, for that matter, do prescriptions laid down in the Arthasastra. A similar argument could have been made vis-a-vis the script. Both the Harappan and the Ganga Valley civilisations provide evidence for the use of writing, but attempts to derive the Brahmi script from the Harappan have not been particularly successful. Once again, the use of scripts can be better understood as an example of general civilisational traits.
What then are the more tangible elements of continuity? The authors point to that well-worn symbol of changeless India, the bullock cart, and the wooden plough. But, even as we concede that the existence of civilisations is impossible without adequate means of transport and agricultural production, these in themselves are not synonymous with civilisation. As such, their continued existence or disappearance is probably not terribly important for the question of civilisational continuity.
Other problems remain unexplored. The heartland of the Ganga Valley civilisation was eastern UP and Bihar, with centres such as Kasi, Kausambi, Pataliputra and Vaisali. These were peripheral from the perspective of the early and to a lesser extent the later Vedic traditions. Conversely, once civilisa-tion developed in the Ganga Valley, the northwest was regarded as marginal within the later Brahmanical tradition. Such attitudes seem representative of civilisational disjunctures. Besides, the question of the extent to which that elusive entity, Indian civilisation, is synonymous with either the Harappan or the early historical Ganga Valley civilisations, or a combination of the two, remains unaddressed.
