The 6th and 5th centuries BC saw the appearance of a remarkable number of philosophers and thinkers all over Eurasia whose influence continues to this day:
- Socrates (470 - 399 BC), "father of Western philosophy"
- Zoroaster (ca. 550 BC), founder of Zoroastrianism
- Buddha (traditionally dated 480 - 400 BC), founder of Buddhism
- Mahavira (599 - 527 BC), founder/reformer of Jainism
- Confucius (551 - 479 BC), founder of Confucianism
- Laozi (ca. 6th century BC), founder of Taoism
Leaving aside the question of whether some of these individuals are historical people or merely legends to whom the pivotal works of the period were attributed, this places what are commonly considered the originators of Western, Persian, Indian and Chinese philosophy all within a timeframe of 200 years, although (with the possible exception of Confucius and Laozi) there is no account of any of them actually meeting.
It is therefore not unreasonable to assume that the simultaneous origin of so many major schools of thought reflects a large-scale movement across the loosely connected "meta-civilization" Greece–Persia–India–China. Is there any evidence of such a movement indeed occurring? Confucius and Laozi are commonly assigned to the "Hundred Schools of Thought" period during which Chinese philosophy as a whole flourished, but I have yet to see any explanation (apart from simple coincidence) which places them in the larger context of their contemporaries from other parts of the world.