Originally published in 1956, this book provides a clear, scholarly, introduction to the main tenets of Zoroastrian dualism presented largely in the words of the Zoroastrian texts themselves. The book demonstrates the essential reasonableness of Zoroastrian dualism, which is the dualism of a good and an evil spirit, and to show what the means in everyday life and how it is philosophically justified. There are chapters on cosmology, the relation of man to God, the nature of religion, ethics, sacraments and sacrifice, the soul’s fate at death and eschatology.
Robert Charles Zaehner had a gift for languages and became an expert in Oriental languages. As a result, he was chosen as a British counterintelligence agent in Tehran, Persia during World War II and an MI6 agent there after the war. He returned to academia and became Spalding Professor of Eastern Religions and Ethics at the University of Oxford and a Fellow of All Souls College, writing numerous books on religion, both eastern and western.
Information adapted from Wikipedia and the back cover of The Bhagavad-Gita which he translated and authored