Persia must have been even at this time in close contact with India, for about the date of the death of Pythagoras, in the reign of Dareius, son of Hystaspes, at the end of the sixth and beginning of the fifth century before our era, we hear of the expedition of the Persian general Scylax down the Indus, and learn from Herodotus that in this reign India (that is the Punjāb) formed the twentieth satrapy of the Persian monarchy. Moreover, Indian troops were among the hosts of Xerxes; they invaded Thessaly and fought at Platæa. From the time of Alexander onwards there was direct and constant contact between Āryāvarta and the kingdoms of the successors of the world-conqueror, and many Greeks wrote about this land of mystery; but in all that has come down to us we look in vain for anything but the vaguest indications of what the “philosophers” of India systematically thought. That the Brāhmans would at this time have permitted their sacred books to be read by the Yavanas (Ionians, the general name for Greeks in Indian records) is contrary to all we know of their history. The Yavanas were Mlechchhas, outside the pale of the Āryas, and all they could glean of the jealously guarded Brahmā-vidyā or theosophy must have depended solely upon outside observation. But the dominant religious activity at this time in India was Buddhist, and it is to this protest against the rigid distinctions of caste and race made by Brāhmanical pride, and to the startling novelty of an enthusiastic religious propaganda among all classes and races in India, and outside India to all nations, that we must look for the most direct contact of thought between India and Greece. For instance, in the middle of the third century B.C., we know from Asoka’s thirteenth edict, that this Buddhist Emperor of India, the Constantine of the East, sent missionaries to Antiochus II. of Syria, Ptolemy II. of Egypt, Antigonus Gonatas of Macedonia, Magas of Cyrene, and Alexander II. of Epirus. When, in a land of such imperfect records, the evidence on the side of India is so clear and indubitable, all the more extraordinary is it that we have no direct testimony on our side of so great a missionary activity. Although, then, merely because of the absence of all direct information from Greek sources, it is very unsafe to generalize, nevertheless from our general knowledge of the times it is not illegitimate to conclude that no great public stir could have been made by these pioneers of the Dharma in the West. In every probability these Buddhist Bhikṣhus produced no effect on the rulers or on the people. But was their mission entirely abortive; and did Buddhist missionary enterprise westwards cease with them?