Zoroastrianism was unlike other pagan religions in this, that it could not fail to admit and preserve the ancient tradition of a first sin. Rather would it have been forced to construct for itself an analogical myth, had it not found such in the primitive memories that it bent to its own doctrines. The tradition squared, indeed, but too well with its system of a dualism having a spiritual basis, although as yet but imperfectly freed from confusion between the physical and moral worlds. It explained quite naturally how man, a creature of the good God, and consequently originally perfect, should have fallen under the power of the evil spirit, thus contracting a taint which in the moral order subjected him to sin, in the material to death, and to all the miseries that poison earthly existence. Thus the notion of the sin of the first authors of humanity, the heritage of which weighs constantly on their descendants, is a fundamental one in Mazdean books. The modification of legends relative to the first man even resulted in the mythic conceptions of the later periods of Zoroastrianism, in attaching a rather singular repetition of this first transgression to several successive generations in the initial ages of humanity.
Originally--and this is at present one of the points most solidly established by science--originally in those legends common to Oriental Aryans before their separation into two branches, the first man was the personage that the Iranians call Yima, and the Indians Yama. A son of Heaven and not of man, Yima united the characteristics that Genesis divides between Adam and Noah, fathers both, the one of antediluvian, the other of postdiluvian humanity. Later, he appears as merely the first king of the Iranians, but a king whose existence, as well as that of his subjects, is passed in the midst of Edenic beatitude in the paradise of Airyana-Vædja,[53] the dwelling-place of the earliest men. But after a time when life was pure and spotless, Yima committed the sin which weighs on his descendants, and in consequence of that sin, lost his power, was cast out of Paradise, and given up to the dominion of the serpent, the evil spirit Angromainyus,[54] who finally brought about Yima's death by horrible torments.[55] It is an echo of the tradition about the loss of Paradise ensuing upon a transgression prompted by the Evil Spirit that we find in what is incontestably one of the oldest portions of the Sacred Scriptures of Zoroastrianism.[56] "I created the first and the best of dwelling-places. I who am Ahuramazda: the Airyana-Vædja is of excellent nature. But against it Angromainyus, the murderer, created a thing inimical, the serpent out of the river and the winter, the work of the Doevas."[57] And it is this scourge, caused by the power of the serpent, which occasions the departure for ever from the paradisiacal region.