The theory, originally proposed by Franz Cumont, that Mithraism evolved from Persian Zoroastrianism, is now generally dismissed. However, the theory has not been carefully examined. A primitive version of the Mithraic mysteries certainly existed among them, as can be determined from circumstantial evidence, where they contributed heavily to the Greek traditions of Orphism, which not only later emerged as prominent themes in Mithraism, but of Hellenistic mysticism in general.