5.7 Export of culture
The tradition of the Brahmins, a key component of mainstream Hindu religion, preserves not just the four Vedas but a great variety of later Sanskrit texts of diverse content. For example ancient Indian atomism promotes the idea that matter is made up of atoms. Buddhism eventually disappeared in India itself, but a large Buddhist literature originally composed there still survives among Buddhists in Ceylon and elsewhere in a variety of languages. Jainism, a religious movement of the same character as Buddhism but slightly older, is today confined to two widely separated populations in India; one of them has preserved a literary heritage reaching back into the first millennium B.C. The documentation for the religious history of ancient India is thus as rich as that for its political history is poor. What this material suffers from,is a certain historical disembodiment. For example, the Buddhist scriptures of Ceylon are in an Indo-Aryan language known as Pali, which indicates that this must once have been the vernacular language of real people living in a real place, but we can only guess where in northern India that might have been.
The survival of Indian Buddhist texts outside India implies the spread of Indian civilization to regions beyond the subcontinent. This did not involve conquest. The northwest, in fact, has always been a gateway through which foreigners invade India, and never the other way around. Instead, the process seems to have been rather similar to the reception of north Indian culture in the south.
The enduring legacy of Indian influence in the Asian interior was the spread of Buddhism.  This process of borrowing had brought Buddhism from northwest India around the top of Tibet to the borders of China. In this region we have evidence from the second century A.D. of culturally Indianized states among peoples that had previously lacked literate culture. Several centuries later something similar was to happen in Tibet.
In roughly the same period, Indian civilization began to make its influence felt in parts of Southeast Asia. The precondition for this was the rapid development of long-distance trade on the Indian Ocean, dramatically illustrated by the presence of Roman artifacts at Go Oc Eo in what is now Vietnam (including a gold medallion of the emperor Antoninus Pius dating from A.D. 152). As in southern India, the process meant a dramatic increase in employment opportunities for Brahmins of fortune. A fifth-century Chinese source mentions the presence in one Southeast Asian kingdom of over a thousand Indian Brahmins, to whom the local people would give their daughters in marriage. But there seems to have been less Indianization of society at large.   Unlike the peoples of the Indian south, those of Southeast Asia do not have well- developed caste systems. So it was primarily the elites and rulers of the region who had a use for Indian civilization. This use was nevertheless considerable. Inscriptions attest the emergence of Indianized states from the third century A.D., and by the end of the millennium numerous such states had appeared on the mainland and some of the islands.
We can end this survey by noting an interesting asymmetry about the export of Indian culture.  It achieved its successes to the east, and not to the west. To the east, peoples whose geographical locations gave them a choice between Indian and Chinese culture overwhelmingly chose Indian. The Tibetans provide a further example of this preference: we know that they were at one time interested in both cultures, but they later dropped the Chinese option.
By contrast, there was no such spread of Indian culture to the west. The Near East, of course, already had literate culture, just as China did; but the massive spread of Buddhism in China has no parallel in the Near East, even though Mani respectfully included the Buddha in hIndia is a part of the old supercontinent of Gondwana that has joined Eurasia. India separated from the rest of Gondwana over a hundred million years ago, and until it collided with Eurasia, about fifty million years ago, it was an island. This is reflected in that the Indian subcontinent is a peninsula, not a land bridge. There are nevertheless some broad physical similarities with the Near East. Like the southern Near East, India overall is relatively flat. Inland from the coastal plains of the south there are mountain ranges arising from the rifting that brought the region into being, and between them are the highlands of the interior. But there is nothing in the south to compare in altitude to the combination of mountains and plateau by which India is closed off to the north. Much as in the northern Near East, this massive uplifting is the product not of rifting but of collision. Yet the scale of the uplifting dwarfs anything the Near East has to show; indeed, there may have been nothing on earth to match it in the last half billion years. By contrast, it is between the northern mountains and the southern highlands that India is at its lowest and flattest, with alluvial plains comparable to those of Mesopotamia.