Columbia subject headings:
Harvard subject headings:
Achaemenid dynasty, 559-330 B.C.
Civilization, Ancient--Philosophy.
Iran--Antiquities.
Iran--Civilization--To 640.
Iran--Religion.
Jaspers, Karl, 1883-1969
Rationalism--History.
Zoroastrianism
Princeton subject headings:
Iran--Religion.
Rationalism--History.
Zoroastrian philosophy.
Zoroastrianism.