We often assume that ancient religions were purely ceremonial, yet some of the earliest faiths tied cosmic survival directly to human behavior. This tension between a supreme, good deity and the independent existence of evil forced early thinkers to construct a rigorous framework for human free will.

In this episode, we follow the life of the prophet Zarathustra and the evolution of Zoroastrianism in ancient Persia. We discuss how early priests reorganized traditional pantheons, demoting older gods into angelic servants or demonizing them into the very concept of the devil. The discussion covers the rise of a state-supported Zoroastrian church under the Sasanians, the impact of Arab conquests on religious status, and how the sacred fire came to symbolize truth and justice.

• Deconstructing the linguistic and mythological transition ...