Concepts of the nature of existence, the creator of the universe, and the position of humankind have varied across civilizations, with significant differences evident among religious and mythological traditions. This study examines the cosmological views of ancient Iranian and Greek civilizations—two early cultures that mutually influenced one another—focusing on their perceptions of the universe, the material world, and humanity’s place within it. Using a descriptive–analytical approach and library-based research on key Iranian and Greek sources, the study explores similarities and differences in their mythological and religious thought.

The findings show that while some shared ideas exist regarding the nature of the cosmos and the earth, fundamental differences remain concerning the existence of a creator, the finitude or infinitude and the created or eternal nature of the universe, as well as the role and destiny of humankind. The Iranian worldview, particularly within Mazdean beliefs, presents a more coherent and teleological system in which the material and spiritual realms are interconnected and humanity functions as a microcosm within the macrocosm. In contrast, Greek thought, shaped by diverse mythological and philosophical traditions from the Homeric period onward, lacks a unified cosmology and assigns humanity a largely non-determinative role in the origin of the universe.