66 SOCIAL SCIENTIST not only historical interpretation but have become the foundation of political modern ideologies.8 These two schools of historical interpretation naturally clashed against each other on a number of points. There are however certain matters on which substantial sections of the national school found themselves in agreement with the imperialist school. Romila Thapar addresses herself to some of these common points and effectively combats them on the basis other scientific analysis of objective facts. One of these relates to the role played by the Aryan immigration into India which was for long considered to be the starting-point of Indian history. This theorv was of course exploded with the discovery of ihe remains of the Indus Valley Civilization and the enormous material that has been accumulated after those discoveries at Harappa and Mohenjo-Daro. It is now possible for historians to reconstruct a more rational, a more scientific interpretation of Indian history in which the Aryan immigration plays a less significant role than it did earlier. Aryan Civilisation Theory i Basing herself on this rich material that has been accumulated, the author disposes of ^the notion of the Aryan race" as e 'alien to the Indian tradition".8 After discussing the various aspects of this notion, she comes to the conclusion: The historians therefore cannot but doubt the theory that a large number of Aryans conquered northern India, enslaving the existing population and thereby established their language and culture, both entirely alien to the indigenous tradition. It has to be conceded that, if there was a conquest, it was limited to parts of the extreme North. It is more likely that groups of Aryan-speaking people migrated into northern India, and settled and mixed up with the indigenous population. The culture that resulted evolved from this interaction. The widespread adoption of the Indo-Aryan language in nothern India was a major expression of this new culture. Such a phenomenon takes on the dimensions of a social force and has to be seen historically in that light.4 The question naturally arises why, and on ihe basis of what objective factors, surh a widespread adoption of the Indo-Arvan language became possible. The author's answer is: At the beginnirg of the first millen^um B C two innovations of great consequence appear on the Indian scene. One was the extensive use of the horse, an animal comparatively new to the sub-continent, and the other was a familiarity with iron technology... The spoked-wheel chariot drawn by the horse was a technological advance in transportation over the ox-drawn cart. The use of iron improved on a variety of skills which had previously depended on the less durable and weaker metals of copper and bronze. Frequent references to the solar calendar in literature point to an improvement in astronomy and