I'm familiar with Hericlitus, and have studied the pre-Socratics, at least what's left of them. The article notes that materialism started to form piecemeal in the "last three millennia", which includes Hericlitus. When I say ancient, on the other hand, I mean really ancient, like 5000-10000 years; as well as what remnants of it exist in written record, what anthropologists studied in tribal cultures, and what has carried over into modern religions. The last 3000 years are a transitional phase.