Thales (Thales) think water is the source of all things; Anaximenes (Anaximenes) believe air is the source of all things; Heraclitus (Heraclitus) think the fire is the source of all things.
Thales believed that water was the source of all things; Anaximenes believed that air was the source of all things; Heraclitus believed that fire was the source of all things.