Heraclitus

Heraclitus of Ephesus (c. 535 – c. 475 BC) was a pre-Socratic Greek philosopher, and a native of the city of Ephesus. Heraclitus was famous for his insistence on ever-present change as being the fundamental essence of the universe, as stated in the famous saying, "No man ever steps in the same river twice". This position was complemented by his stark commitment to a unity of opposites in the world, stating that "the path up and down are one and the same". 

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