Kristen Szumyn in her article “The Barbarian wisdom of the ‘theoi andres’ : a study of the relationship between spatial marginality and social alterity” writes (after Clement of Alexandria): “Herodotus associates the possession of ‘wisdom’ (sophias) and ‘knowledge’ (philosopheon) with one who has extensively ‘travelled’ (planes) to foreign lands. Such a person is counted amongst the saphistai, the wise men or teachers. The Greek philosopher’s visit to foreign countries was a doxographical and biographical topos specifically associated with the attainment of wisdom. The philosophical and religious wisdom attained by such travellers was essentially ‘barbarian’. As Diogenes Laertius noted, the later Neoplatonic tradition held that ‘the study of philosophy had its beginning among the barbarians… the Persians have their Magi, the Babylonians or Assyrians their Chaldeans, and the Indians their Gymosophists; and among the Celts and Gauls there are the people called Druids or Holy Ones. These marginalised religious teachers and transmitters of spiritual wisdom are associated with the geographical and social periphery of society. This geographical marginality of the wise man is particularly evident in the Neoplatonic tradition of late antiquity; however this notion of the association between the sage and oriental or barbarian wisdom was a concept well established even in early Greek thought.”
“Gymnosophists is the name (meaning “naked philosophers”) given by the Greek to certain ancient Indian Philosophers who pursued asceticism to the point of regarding food and clothing as detrimental to purity of thought (sadhus or yogis).
The Digambar Jain monks in India even now remain unclothed; they have been identified as the gymnosophists by several researchers; Xuanzang mentions having come across Digambar Jain monks in Taxiladuring his 7th century CE visit to India in the same Punjab region where Alexander encountered the gymnosophists.” (from wiki)
Plutartch wrote of Alexander’s meeting in the First Century with 10 Gymnosophists in the Punjab:
“He (Alexander) captured ten of the Gymnosophists who had done most to get Sabbas to revolt, and had made the most trouble for the Macedonians. These philosophers were reputed to be clever and concise in answering questions, and Alexander therefore put difficult questions to them, declaring that he would put to death him who first made an incorrect answer, and then the rest, in an order determined in like manner; and he commanded one of them, the oldest, to be the judge in the contest. The first one, accordingly, being asked which, in his opinion, were more numerous, the living or the dead, said that the living were, since the dead no longer existed. The second, being asked whether the earth or the sea produced larger animals, said the earth did, since the sea was but a part of the earth. The third, being asked what animal was the most cunning, said: “That which up to this time man has not discovered.” The fourth, when asked why he had induced Sabbas to revolt, replied: “Because I wished him either to live nobly or to die nobly.” The fifth, being asked which, in his opinion, was older, day or night, replied: “Day, by one day”; and he added, upon the king expressing amazement, that hard questions must have hard answers. Passing on, then, to the sixth, Alexander asked how a man could be most loved; “If,” said the philosopher, “he is most powerful, and yet does not inspire fear.” Of the three remaining, he who was asked how one might become a god instead of man, replied: “By doing something which a man cannot do”; the one who was asked which was the stronger, life or death, answered: “Life, since it supports so many ills.” And the last, asked how long it were well for a man to live, answered: “Until he does not regard death as better than life.” So, then, turning to the judge, Alexander bade him give his opinion. The judge declared that they had answered one worse than another. “Well, then,” said Alexander, “thou shalt die first for giving such a verdict.” “That cannot be, O King,” said the judge, “unless thou falsely saidst that thou wouldst put to death first him who answered worst.”—Plutarch, Life of Alexander, “The parallel lives,” 64.,