Abracadabra is of unknown origin, and its first occurrence is in the second century works of Serenus Sammonicus, according to the Oxford English Dictionary. Several folk etymologies are associated with the word: from phrases in Hebrew that mean “I will create as I speak”, or Aramaic “I create like the word”, to folk etymologies that point to similar words in Latin and Greek such as abraxas. According to the OED Online, “no documentation has been found to support any of the various conjectures.” The first known mention of the word was in the third century AD in a book called Liber Medicinalis (sometimes known as De Medicina Praecepta Saluberrima) by Quintus Serenus Sammonicus, physician to the Roman emperor Caracalla, who in chapter 51 prescribed that malaria sufferers wear an amulet containing the word written in the form of a triangle, or “abracadabrangle”. The power of the amulet, he explained, makes lethal diseases go away. Other Roman emperors, including Geta and Alexander Severus, were followers of the medical teachings of Serenus Sammonicus and may have used the incantation as well.
It was used as a magical formula by the Gnostics of the sect of Basilides in invoking the aid of beneficent spirits against disease and misfortune. It is found on Abraxas stones, which were worn as amulets. Subsequently, its use spread beyond the Gnostics. The Puritan minister Increase Mather dismissed the word as bereft of power. Daniel Defoe also wrote dismissively about Londoners who posted the word on their doorways to ward off sickness during the Great Plague of London. But Aleister Crowley regarded it as possessing great power; he said its true form is abrahadabra. The word is now commonly used as an incantation by stage magicians when performing a magic trick. It is also applied contemptuously to a conception or hypothesis purporting to be a simple solution of apparently insoluble phenomena.
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