The study of religion, like the study of poetry, brings us face to face with the fundamental principles of human nature. Religion, whether it be natural religion or that which is formulated in a book, is as universal as poetry, and like poetry, existed before letters and writing. It is only in a serious and sympathetic frame of mind that we should approach the rudest forms of these two departments of human activity. A general analysis of the "Zend-Avesta" suggests to us the mind of the Persian sage Zarathustra, or Zoroaster, fixed upon the phenomena of nature and life, and trying to give a systematized account of them. He sees good and evil, life and death, sickness and health, right and wrong, engaged in almost equal conflict. He sees in the sun the origin of light and heat, the source of comfort and life to man. Thus he institutes the doctrine of Dualism and the worship of Fire. The evil things that come unexpectedly and irresistibly, he attributes to the Devas: the help and comfort that man needs and often obtains by means which are beyond his control, he attributes to the "Holy Immortal Ones," who stand around the Presence of Ormuzd. As he watches the purity of the flame, of the limpid stream, and of the sweet smelling ground, he connects it with the moral purity which springs from innocence and rectitude, and in his code it is as reprehensible to pollute the fire by burning the dead, or the stream by committing the corpse to its waves, or the earth by making it a burial-place, as it is to cheat or lie or commit an act of violence. The wonders of Nature furnish abundant imagery for his hymns or his litanies, and he relies for his cosmogony on the faint traditions of the past gathered from whatever nation, and reduced into conformity with his Dualistic creed. "Zend-Avesta" is the religious book of the Persians who professed the creed of Zarathustra, known in classic and modern times as Zoroaster. Zoroaster is to be classed with such great religious leaders as Buddha and Mohammed. He was the predecessor of Mohammed and the worship and belief which he instituted were trampled out in Persia by the forces of Islam in the seventh century of our era. The Persian Zoroastrians fled to India, where they are still found as Parsis on the west coast of Hindostan. The religion of Zoroaster was a Dualism. Two powerful and creative beings, the one good the one evil, have control of the universe. Thus, in the account of the creation, the two deities are said to have equal though opposite share in the work. This is indicated by the following passage-- The third of the good lands and countries which I, Ahura Mazda (Ormuzd) created, was the strong, holy Môuru (Merv). Thereupon came Angra Mainyu (Ahriman), who is all death, and he counter-created plunder and sin.