Ancient Iran: Cosmology, Mythology, History presents Iran's pre-Islamic history within the context of both its complex cosmology and rich mythology. The book uses the concept of farr to show how authority, finding guidance in the cosmic realm, organized the lives of Iran's hero-saints in the mythic realm. It also discusses how historical monarchs organized their hierarchical societies according to the dictates of Ahura Mazda.

The book is divided into three parts. The first part examines cosmology, concentrating on Ahura Mazda and the Ahuric order that emanates from him. The next section addresses mythology and describes how the rulership of hero-saints promoted the farr, culminating in the unique creed of Zoroaster. The final section tells the history of pre-Islamic Iran. It begins with a study of life on the plateau, moves on to the stages of empire and concludes with the rule of the Parthians and Sassanids.

Additionally, through a new interpretation of Firdowsi's Shahname, the volume shows how the prophet Zoroaster reorganized Mazdian cosmology to fit the ethical, philosophical, and sociological dynamics of Achaemenid and Sassanid Iran.