Mithraism from other sects and inspired its dogmatic theology and ethics, giving them a rigor and firmness unknown to Roman paganism. It considered the universe from an entirely new point of view and at the same time provided a new goal in life.
Of course, if we understand by dualism the antithesis of mind and matter, of reason and intuition, it appeared at a considerably earlier period in Greek philosophy,[[34]] where it was one of the leading ideas of neo-Pythagoreanism and of Philo's system. But the distinguishing feature of the doctrine of the magi is the fact that it deified the evil principle, set it up as a rival to the supreme deity, and taught that both had to be worshiped. This system offered an apparently simple solution to the problem of evil, the stumbling block of theologies, and it attracted the cultured minds as well as the masses, to whom it afforded an explanation of their sufferings. Just as the mysteries of Mithra began to spread Plutarch wrote of them favorably and was inclined himself to adopt them.[[35]] From that time dates the appearance in literature of the anti-gods (ἀντίθεοι),[[36]] under the command of the powers of darkness[[37]] and arrayed against the celestial spirits, messengers or "angels"[[38]] of divinity. They were Ahriman's devas struggling with the Yazatas of Ormuzd.
A curious passage in Porphyry[[39]] shows that the earliest neo-Platonists had already admitted Persian demonology into their system. Below the incorporeal and indivisible supreme being, below the stars and the planets, there were countless spirits.[[40]] Some of them, the gods of cities and nations, received special names:
the others comprised a nameless multitude. They were divided into two groups. The first were the benevolent spirits that gave fecundity to plants and animals, serenity to nature, and knowledge to men. They acted as intermediaries between gods and men, bearing up to heaven the homage and prayers of the faithful, and down from heaven portents and warnings. The others were wicked spirits inhabiting regions close to the earth and there was no evil that they did not exert every effort to cause.[[41]] At the same time both violent and cunning, impetuous and crafty, they were the authors of all the calamities that befell the world, such as pestilence, famine, tempests and earthquakes. They kindled evil passions and illicit desires in the hearts of men and provoked war and sedition. They were clever deceivers rejoicing in lies and impostures. They encouraged the phantasmagoria and mystification of the sorcerers[[42]] and gloated over the bloody sacrifices which magicians offered to them all, but especially to their chief.
Doctrines very similar to these were certainly taught in the mysteries of Mithra; homage was paid to Ahriman (Arimanius) lord of the somber underworld, and master of the infernal spirits.[[43]] This cult has continued in the Orient to the present day among the Yezidis, or devil worshipers.
In his treatise against the magi, Theodore of Mopsuestia[[44]] speaks of Ahriman as Satan (Σατανᾶς). At first sight there really is a surprising resemblance between the two. Both are heads of a numerous army of demons; both are spirits of error and falsehood, princes of darkness,
tempters and corrupters. An almost identical picture of the pair could be drawn, and in fact they are practically the same figure under different names. It is generally admitted that Judaism took the notion of an adversary of God[[45]] from the Mazdeans along with portions of their dualism. It was therefore natural that Jewish doctrine, of which Christianity is heir, should have been closely allied to the mysteries of Mithra. A considerable part of the more or less orthodox beliefs and visions that gave the Middle Ages their nightmare of hell and the devil thus came from Persia by two channels: on the one hand Judeo-Christian literature, both canonical and apocryphal; and on the other, the remnants of the Mithra cult and the various sects of Manicheism that continued to preach the old Persian doctrines on the antagonism between the two world principles.
But a theoretical adherence of the mind to dogmas that satisfy it, does not suffice to convert it to a new religion. There must be motives of conduct and a basis for hope besides grounds for belief. The Persian dualism was not only a powerful metaphysical conception; it was also the foundation of a very efficacious system of ethics, and this was the chief agent in the success of the mysteries of Mithra during the second and third centuries in the Roman world then animated by unrealized aspirations for more perfect justice and holiness.
A sentence of the Emperor Julian,[[46]] unfortunately too brief, tells us that Mithra subjected his worshipers to "commandments" (ἐντολαί) and rewarded faithful observance both in this world and in the next. The
importance attached by the Persians to their peculiar ethics and the rigor with which they observed its precepts, are perhaps the most striking features of their national character as manifested in history. They were a race of conquerors subject to a severe discipline, like the Romans, and like them they realized the necessity of discipline in the administration of a vast empire. Certain affinities between the two imperial nations connected them directly without the mediation of the Greek world. Mazdaism brought long awaited satisfaction to the old-time Roman desire for a practical religion that would subject the individual to a rule of conduct and contribute to the welfare of the state.[[47]] Mithra infused a new vigor into the paganism of the Occident by introducing the imperative ethics of Persia.