At a later period, when the ancient customs had become relaxed owing to the invasion of the country by foreigners and to the government passing from the hands of native rulers to those of Persian, of Greek or Roman governors, many, besides the priests, came to be admitted to the lesser mysteries. But all had to pass through the different grades and conform to the prescribed rules, as in the case of Thales, Eumolpus, Orpheus, Pythagoras, Plato, Herodotus and others.
I will not here describe at length the initiations to the mysteries in honor of the Sun God, Mithra, instituted by Zoroaster, but only state that Porphyrius, on the testimony of Eubulus, says that this philosopher and reformer having selected a cavern in a pleasant locality in some mountains near Persia, dedicated it to Mithra, the Sun, creator and father of all beings; that he divided it into geometrical figures intended to represent the climates and elements; in a word that he imitated in a small way the order and disposition of the universe by Mithra. After him, it became customary to consecrate caverns for the celebration of mysteries; as we see yet in Japan.
The candidates for initiation to the Mithra mysteries were submitted to the most awful trials—among which one was to try the docility and courage of the applicant. He was ordered by the priest to kill a man. According to Plutarch, in his life of Pompeius, these mysteries were brought to the Occident by Cilician pirates about sixty-eight years before the Christian era. They were well received by the Greco-Latin world, and the initiated were soon to be counted by thousands. In the time of the Emperor Adrian, the mysteries of Mithra had become so popular that Pallas, a Greek writer, composed a poem on the subject, that Porphyrius has preserved in a special treatise on the abstinence from the use of animal flesh.
The mysterious initiations vividly impressed the imagination, as at times and by way of expiation, human victims were offered and immolated. The ceremonies of the priests consisted, says Origenes, in imitating the motions of the celestial bodies, those of the planets, in fact of the heavens. The initiated took the names of the constellations and dressed themselves as animals. A theology purely astronomical was taught in these mysteries, in which they used the purification by water in honor of the goddess _Ardvi çoura anâhita_, "She of the celestial waters;" the confession of sins; and a sort of eucharist, or offering of bread, still observed by the Parsis or fire worshippers in India. It may be said that during the last years of the Roman Empire, the religion of Mithra had become the state religion. It is not, therefore, to be wondered at, if it extended to the Roman provinces of Gaul and Britain, and if some of its rites have found their way into Free Masonry, and are practised to the present day; thus again relating it with very ancient sacred mysteries, established by Zoroaster, the author of the Zend-Avesta at least 1,100 years before Christ, although Hermippus, the Greek translator of his work, places him 5,000 years before the taking of Troy.