The author attempts to give an outline picture of Zoroastriansm, and then of Judaism when it came to be somewhat a fixed system in the post-exilic times, in order to give the leading religious, social, and moral conceptions in each faith. Contents: Zarathustra and the Zeit-Geist; Judaism; the idea of deity; the host of heaven; naturalistic traits; the expectation of a redeemer; civil, social, and ceremonial regulations; morals and ethics; the future life.