The Mysteries were thus cults in which all religious functions were closed to the non-inducted and for which the inner-working of the cult were kept secret from the general public. Although there are no other formal qualifications, mystery cults were also characterized by their lack of an orthodoxy and scripture. Religions that were practiced in secret only in order to avoid religious persecution are not by default Mysteries.
The Mysteries are frequently confused with Gnosticism, perhaps in part because Greek gnosis means "knowledge." The gnosis of Gnosticism is however distinct from the arcanum, the "secret wisdom" of the Mysteries: while the Gnostics hoped to acquire knowledge through divine revelation, the mystery religions presumed to have it, with mystes of high rank revealing the possessed wisdom to acolytes of lower rank.
"Plato, an initiate of one of these sacred orders, was severely criticized because in his writings he revealed to the public many of the secret philosophic principles of the Mysteries."
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