Lao Tzu would be my first choice, but he is so mysterious a character that I doubt hecan be pinned down historically.
I guess my vote would be for Confucius - a contemporary of Pythagoras of Samos. It's wonderful to think of these two great men living at the same time, divided by thousands of miles and unbridgeable cultural divides.
Makes you wonder what other great people go unknown to us. There were no doubt thinkers of genius in the South Americas civilisations who are unknown to us. Even today, there will be among the pastoral tribes of Africa or the hill people of South East Asia, men and women who are the Einstein or Curie of their science, the Aquinas or al-Ghazali of their religion, the Sojourner Truth of their society, their Mozart, their Leonardo.
It's all cultural, really.
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