Israel's representative at the recent Eurovision Song Contest, Harel Skaat, unashamedly flaunted a kemaye - a Hebrew amulet - on his bared chest during his performance. "I believe in all these superstitions," he confessed.
Skaat is not alone. Superstition and magic among Jews has a history stretching back to biblical times. It is said that the first amulet was the "sign" given by God to Cain to protect him from potential assassins.
A new exhibition, called "Angels and Demons", in Jerusalem's Bible Lands' Museum offers a panoramic view of this Jewish fascination with magic. It brings together written and graphic material from across the centuries and around the globe displaying what the classic book on the subject, Joshua Trachtenberg's Jewish Magic and Superstition, calls "a folk religion". Alongside legitimate Judaism another, subterranean belief system has persisted, attracting rabbis, scholars and laymen alike.
The Bible is openly antagonistic to such beliefs: "You shall not let a witch live" (Exodus 22:17); "It is forbidden to practice necromancy or witchcraft" (Leviticus 19: 31; 20:6 and Deuteronomy 18: 10-12) are typical expressions of this attitude. Incidents involving witchcraft - Balaam in the Torah (Numbers 22-25) and the witch of En-Dor (I Samuel 28: 7-25) - demonstrate how such manipulations of the world of the spirit are invariably dangerous, if not fatal.
Yet post-biblical texts - Mishnah, Talmud and Midrash - seem to soften their approach towards these suspect behaviours. Although here, too, the majority opinions rail against what are perceived as "ways of the Amorites" (eg Tractate Shabbat, Tosefta 7 and 8), the sages were apparently unsure as to where genuine healing ended and witchcraft began. In Mishnah Shabbat (6:10), for example, opinions differ over whether the use of a locust's egg, a jackal's tooth, or the nail from the gallows of an executed criminal, was sorcery or a legitimate means of healing. In another source in the same Mishnah (8:3), it is suggested that the writing of amulets (kamayot) was the norm.
Over the centuries, all sorts of superstitious notions were held by Jews across the globe, by Ashkenazim and Sephardim alike. The Jerusalem exhibition (which will run for at least a year) supplies visual data of these exotic beliefs - magic bowls, scarabs, incantations, kabbalistic texts and chamsas.
Also on display is a young boy's shirt holding various charms in its pockets. It was found by the late Yigal Yadin in the same cave as the letters of Bar Kochba overlooking the Dead Sea. The fact that such a charmed vest would be used by this group of spiritual seekers back in the second century attests to the depth to which these customs had taken hold of the people.
The museum exhibits items used for white magic as a protection against malevolent spirits and for black magic, which is used actively against one's mortal enemies. Amulets on display are written in Hebrew, Aramaic and even Arabic, alongside five-pronged chamsas. Magic bowls are also shown, upside down and buried in the exhibition's floor as they used to be in ancient Mesopotamia at the threshold of a house.
In an accompanying film showing the persistence of this exotic tradition in the contemporary world, a certain Mr Yitzhaki offers to write personalised amulets, writing his client's name on a piece of klaf (animal skin used by scribes) next to which the client writes their wishes.
Professor Gideon Bahak, an expert on Jewish magic, has spent years examining the Geniza Archives in Cambridge. In a lecture at the museum, he said that he had so far found 2,500 items linked to magic and superstitions. "Since the Geniza, formerly located in Cairo, covers a period from 1000 to 1900, it is fairly clear that these practices were widespread and accepted as legitimate for believing Jews," he said. He also observed that not a few Jews made a living out of writing amulets, magic bowls and the like, for both their Jewish and non-Jewish neighbours.
The museum guides point out that many of our "Jewish" symbols have their origins in other cultures. The five-fingered hand or chamsa is most likely borrowed from an Islamic symbol for the five basic laws of that faith. The Magen David is thought to have originated in India and made popular in Jewish circles by the 12th-century false Messiah David Alroy, who is the true David of the symbol.
Similarly, the widespread figure of the holy warrior slaying Satan - while claimed as depicting Solomon defeating Ashmodeus, King of the evil spirits - is almost definitely Christian in origin and indeed at one point was transformed into St George slaying a fiery British dragon.
For the rabbis, the dangers inherent in these beliefs and practices were tempered by the fact that they recognised an invisible, spiritual world - a parallel universe - that has great potency for our mundane existence. For Maimonides, black magic is forbidden "because of idolatry, for the supernatural powers drawn are attributed to forces other than God".
Gershon Winkler, the "shamanic" rabbi, comments: "For every truth, there exists its false counterpart, which tests and lends credibility to one's faithfulness, motivation and conviction." Or, as Professor Bahak points out: "Even in the Bible, it nowhere says that these practices and beliefs don't work."
As for Mr Skaat, his song Words did gain 12th place - symbolic no doubt of the Twelve Tribes of Israel. Perhaps his opponents simply had more potent amulets.