There are some very dark passages in the Old Testament, stories of lust and cruelty that have no obvious moral. Incest, bigamy, rape, mutilation, deceit, loyalty and love can all be found in the Good Book.
Nathan Abrams, from Bangor University, Wales, has now taken the risky step of putting together a book entitled Sex and the Jews, a collection of essays on aspects of Jewish life which he thinks deserve more attention than they have received, such as Yiddish lesbian poetry.
One of the contributions is an essay by Geoffrey Dennis, a rabbi based in north Texas, on Jewish erotic theology, which looks at some of the raunchier passages from the Old Testament. Another American academic, Jay Michaelson, who is openly gay, has contributed an essay on why it is possible to be both an orthodox Jew, and gay, despite a notorious Old Testament verse which lays down that men who sleep with other men should be killed.
Written by different authors, possibly at very different times, the Old Testament can be self-contradictory. The story in 1 Samuel of the friendship between David, the handsome young warrior who has just killed Goliath, and Jonathan, son of King Saul, is often interpreted as a tale of gay love. In one verse, it says: "And it came to pass ... that the soul of Jonathan was knit with the soul of David, and Jonathan loved him as his own soul." If they were gay lovers, there is no indication that the God of the Old Testament disapproved, a reaction that fits comfortably with modern enlightenment culture.
In other passages, God's attitude to sex seems shockingly repressive, as when, for instance, he pronounces a death sentence on Onan, for pleasuring himself in a way that denied his wife the chance to become pregnant. Hardline theologians might like the idea that all sex is sinful other than for the purpose of procreation, but for the more liberal-minded, it is a tricky story. It arises from a culture in which a woman's standing in the community and sense of self-worth depended heavily on her capacity to produce children.
Dr Abrams, who comes from a Jewish family, was also struck by the curious morality of the Old Testament, as displayed by Lot, a righteous man who offers hospitality to travellers passing through Sodom, and when a mob gathers wanting to rape the men, offers his virgin daughters instead. It is as if the girls' virginity belongs to their father, who is so good that he is prepared to sacrifice this precious possession for the sake of his guests. Later, when the going gets rough, Lot is seduced by those same daughters - another tale of the desperate lengths women went to achieve motherhood.
"I think the lesson to be drawn from this story is about what can happen sometimes when people are set obsessively on a certain path, even if it is the right path," Dr Abrams said. He is now bracing himself for the reaction he can expect to his book, either from traditional Jews or, at the opposite extreme, from people who will see the book as food for their anti-Semitic prejudices.
"I'm not a theologian, and I don't speak for any organisation or community. I just want to start a discussion on issues that might not have been discussed in this detail before. These are serious essays by people who have been studying these subjects for a long time ... These essays haven't been written to shock and they're not sensationalist or purely prurient.
"There are parts of the Jewish community that don't like us airing our dirty laundry in public ... and there are anti-Semites who will like what we are doing. They will say it justifies their view of Jews as sexually corrupting. I don't think these people should stop us having a healthy debate."
The book, published last week by Five Leaves, will have its formal launch on Thursday, when the Jewish Museum is hosting a panel discussion in north London.
The harlot by the roadside
Judah was the fourth son - and chosen heir - of Jacob and Leah. But he had married a Canaanite, so his three sons were not pure Hebrew; and he had no grandchildren. After his first son had died childless, his widow, Tamar, married Judah's second son, Onan, who also died. Custom dictated that she should then marry the third son, but Judah wanted her out of the family. Tamar, undeterred, disguised herself as a prostitute and waited to seduce Judah as he came in from the fields. Months later, Judah heard that his unwanted daughter-in-law was pregnant and sent for her to be judged and condemned. He discovered, to his surprise, that he had sired an heir in his old age. "She hath been more righteous than I," was his verdict.
Another take on the tale of Judah and Tamar. Onan's older brother had sinned, so God killed him. Onan's dad said: "Go in to thy brother's wife and marry her, that thou mayest raise seed to thy brother." In other words, their children would, legally, count as the dead brother's children. Onan disagreed so he "spilled his seed upon the ground ... and the Lord slew him, because he did a detestable thing." This has been told to children as a fable of the evils of masturbation, though the text implies all Onan did was commit coitus interruptus.
Ruth and Boaz
This at least is an uplifting love story, though it nearly went wrong. The widow, Ruth, loves Boaz, her husband's relative, but there is a closer relative who is obliged by custom to marry Ruth and perpetuate the dead husband's line. Luckily, he did not want the hassle, so Ruth and Boaz lived happily ever after.
Samson and Delilah