Cultural diffusion of a partially non-literate kind is intrinsically hard to demonstrate and document. The poles between which cultural currents flow across geographical space are not the simple loci of “high” and “low” cultures or of superordinate and subordinate civilizations. Aspects of elite culture trickle down, features of vernacular culture bubble up, to confound and subvert the orderly progression of literary and religious history beloved of conventional scholarship. And, of course, the key occasions of transfer are usually absent from the record.
One such current that is, however, sufficiently documented in general and specific terms to be accepted nem. con. as truly remarkable in volume, longevity and global efficacy is the overwhelmingly one-way traffic of seminal commodities, artifacts and ideas that flowed westward from the South Asian subcontinent between at least 300 B.C.E. and 1400 C.E. Along this stream, from the Punjab via the Iranian plateau and adjacent waterways to Mesopotamia, Syria, the Mediterranean and western Europe, were borne the Gypsies, the game of chess, the mathematical concept of zero and the notation with which to use it, the literary device of the Frame Story, and a flood of stories to stock it.