The story of Alexander’s encounter with a group of fifteen Indian philosophers (described by Plutarch in his Lives of Noble Grecians and Romans – the Life of Alexander, 64) is definitely a historical fact because it was recorded by a man who was present at the scene, Onesicritus, the Cynic philosopher who had accompanied Alexander on his campaign in Asia. Probably with the help of interpreters, Alexander asked the Indian philosophers a series of questions, which were essentially difficult riddles whose answers had to be ambiguous. Here’s an excerpt from Plutarch’s description of the encounter:
“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 die nobly or live." 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 dissatisfaction, that unusual questions must have unusual 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." These philosophers, then, he dismissed with gifts.”
The dialogue between Alexander and the Indian philosophers is called Cynic in Greek and Roman tradition because the Cynic philosopher Onesicritus recorded it. Onesicritus believed that the Indian philosophers epitomized Cynic values because they practiced extreme asceticism—they lived naked and claimed to own nothing except the ground on which they stood. Diogenes Laërtius, the third century Greek philosopher, notes in his Lives and Opinions of Eminent Philosophers that the great skeptic philosopher Pyrrho of Ellis was inspired by Indian thought while he was in India with Alexander, and this caused him to imitate their lifestyle and method of philosophizing after he made his way back to Ellis.
Here’s a brief account of Alexander’s foray into India: He invaded India in 326 BCE and defeated King Porus in the Battle of the Hydaspes on the banks of the Jhelum River. But to go deeper into India, he would have had to declare war on the Nanda empire—according to Plutarch, the encounter with Porus who had “only twenty thousand infantry and two thousand horse” had blunted the spirits of Alexander’s troops and they mutinied at the prospect of encounter with the Nanda empire which reportedly had “eighty-thousand horsemen, two hundred thousand footmen, eight thousand chariots, and six thousand fighting elephants.” Alexander was ultimately convinced by his advisors that he should withdraw from India since his troops were not willing to fight a major battle.