This abr g of Jacob's 2005 study Ātman: A Reconstruction of the Solar Cosmology of the Indo-Europeans (Hildesheim: Georg Olms) focuses on the cosmological insights that inform ancient Indo-European religions and, in particular, on the most significant trinity worshipped by the ancient Indo-Āryans - Agni-Vāyu-Āditya - which represents the forms that the cosmic fire takes in the underworld of Earth before it is installed...