Psi (letter) Psi (letter) Psi (; uppercase ', lowercase '; "psi" ) is the 23rd letter of the Greek alphabet and has a numeric value of 700. In both Classical and Modern Greek, the letter indicates the combination /ps/ (as in English word "lapse"). For Greek loanwords in Latin and modern languages with Latin alphabets, psi is usually transliterated as "ps". The letter's origin is uncertain. It may or may not derive from the Phoenician alphabet. It appears in the 7th century BC, expressing /ps/ in the Eastern alphabets, but /kʰ/ in the Western alphabets (the sound expressed by Χ in the
Alphabet of the Magi the prophets used this letter and that they were forbidden to divulge it to mortal man." Thet alphabet is described in the pseudo-Paracelsian "Archidoxis magica", translated into English by R. Turner (1656). S.L. MacGregor Mathers included it in his 1888 edition of the "Key of Solomon" (plate XV) under the name "Alphabet of the Magi." Alphabet of the Magi Alphabet of the Magi is the modern name of a variant of the Hebrew alphabet used for inscriptions in talismans in 17th-century occultism. It is based on a variant of the Semitic alphabet given by Theseus Ambrosius (1469–1540) in his "Introductio