Simplify the following text for a Grade 8 native English-speaking person.
Original: Heraclitus of Ephesus ( Ancient Greek : -- ; c. 535 -- c. 475 BCE ) was a pre-Socratic Greek philosopher , a native of the Greek city Ephesus , Ionia , on the coast of Asia Minor .
Simplified: Heraclitus of Ephesus ( ca . 535 - 475 BC ) was a pre-Socratic Greek philosopher , a native of Ephesus , Ionia , on the coast of Asia Minor .