What is Zarathustras greatest contribution to spiritual philosophy ?
• Zarathustra’s greatest contribution to spiritual philosophy is the Gathas. They are the prime-utterances of the prophet and forms the quintessence of his religious faith. They are five in number Ahunavaiti, Ushtavaiti, Spentamainyu, Vohukhshatra and Vahishtoisti, composed in archaic metres. Spiritual element preponderates in the Gathas.