Themistoclea (Θεμιστόκλεια, 6th c. BCE) was the priestess of Apollo at Delphi who taught Pythagoras his moral doctrines — making her the earliest known female philosopher and one of the foundational figures of Western thought.
Mentioned in Diogenes Laërtius and Porphyry of Tyre.
Themistoclea reduces to two — the number of Greek priestess.