Heraclitus lived circa 500 BC. He is a Pre-Socratic philosopher as he lived and died before Socrates‘ time. One of his biggest concepts is the idea of logos or reason/meaning dwelling within everything. He also believed that everything in existence necessarily went through constant change.
He is depicted above in Raphael’s painting, the School of Athens.
Quotes:
“If you do not expect the unexpected, you will not discover it.”
“You can’t step in the same river twice.”