AHRIMAN. - In the Mazdean religion, this is the evil principle, that from which every evil originates, also called in older forms angro mainyush. The second part of the compound, mainyush, means “spirit”; the meaning of the first, angro, is still disputed, but probably corresponds to “tormentor, maleficent,” in opposition to spento mainyush, “beneficent spirit.”
In the ancient Avesta, it is opposed not directly to Ahuramazda, but rather to his “beneficent spirit.” Both, the tormentor and the beneficent one, are called “twins” (Yasna 30, 3); they are nevertheless always opposed to one another, since they agree neither in thought, nor in decisions, nor in speech, nor in action (Yasna 45, 2). In the later development of the religion, the beneficent spirit came to be identified with Ahuramazda—a development whose beginnings can also be observed in the ancient hymns—and there arose a direct dualism between Ahuramazda and A. Aristotle already knows this stage of development, when he directly contrasts Oromasdes and Areimanus (Diog. Laerzio, Vita philos., proem. 5). The name Angro mainyush occurs a couple of times in the ancient Avesta; more often, evil is represented therein by druj, “falsehood,” from which the evil teacher—that is, the heretic—and the lying tongue draw their inspiration, and from which ignorance of the true doctrine originates. No creation is attributed to the evil spirit; through free choice, human beings determine themselves for one spirit or the other, and thus dualism and the struggle between good and evil come to exist on earth. The daevas, that is, the divinities of the ancient Iranian polytheism opposed by Zarathustra, chose the evil principle and became demons.
In the course of the cosmic age, each of the two spirits has its own power, but at the end of the world the good principle will definitively triumph over the evil one.
In the Recent Avesta and in the religious literature subsequent to A., a creation opposed to that of Ahuramazda is attributed to him; while the latter creates life and light, he creates death and darkness. To annihilate the good creatures, he employs a terrifying monster, Azhi Dahaka; he disrupts the course of the stars and that of the waters in order to sterilize the earth, and sends innumerable diseases to torment human beings. He dwells in darkness, and on earth gathers his diabolical hosts on Mount Arezura, arrays them for the assault, and launches them into the world. He can transform himself into a horse, a toad, and a serpent. In Pahlavi literature, which draws on lost books of the Avesta, his struggle against Ahuramazda is enclosed within a chronological system of twelve thousand years, divided into four three-thousand-year periods. With the beginning of the third period, the struggle is kindled, and A. succeeds in killing the first man, Gayomart, and the firstborn bull, prototype of animal and plant life; consequently, through the irruption of the evil spirit, a mixture of good and evil comes to exist on earth. At the end of the last period, he will be defeated and evil destroyed; good, on the other hand, will exercise undisputed dominion.