Throughout Western universities, ancient Greek philosophy is seen as the oldest tradition of wisdom, yet the Zoroastrian way of life can be traced back to the second millennium BC. The Gathas - a collection of hymns or songs attributed to Zarathustra - contain an existential and practical philosophy avant la lettre, based on mental exercises and rituals passed down through Zoroastrian religious communities. These texts not only demonstrate the Persian thinker's wisdom, they also introduce an important ecological focus and social practice. In Thus Replied Zarathustra, Ann Van Sevenant presents a cosmopolitan dimension to Zarathustra's proto-philosophy that applies to all of us on an intimate level.