The Allchins, in their archeological capacity, have consistently emphasized the continuity that links the residues of the Indus civilization with tho… - Edmund Leach

Records are preserved because they provide a charter for what historians believe about the present. Different historians may believe different things, and the records are interpreted (and modified) accordingly.

At one time social anthropologists used to complain that their archeologist colleagues had no sense of the overall coherence of human societies. Now, under the influence of Dumézil, who was himself in­ fluenced by Durkheim and Granet, most of the prehistorians who have specialized in India and Pakistan and most of their Indo- Europeanist philological colleagues have become committed to a functionalism of a wholly naive sort. They seem to assume that cultural systems and language systems are bonded together and intrinsically stable over long periods of time. If societies are left alone, they stay put; otherwise, they roll across the landscape like impermeable billiard balls. If the archeological record shows that in fact changes have occurred, their occurrence is always explained as the consequence of a movement of population that carries with it the products (both material and immaterial) of a preexisting, alien, self-contained culture. As a rule, the alleged movement of people takes the form of a military conquest. The mythology of the Dorian invaders of ancient Greece who reduced their Ionian predecessors to serfdom matches point for point the mythology of the Aryan invasion of northern India.

Where the Indo-European philologists are concerned, the invasion argument is tied in with their assumption that if a particular language is identified as having been used in a particular locality at a particular time, no attention need be paid to what was there before; the slate is wiped clean. Obviously, the easiest way to imagine this happening in real life is to have a military conquest that obliterates the previously existing population!