Cultural conservatives do not want to be reminded that there is no Islamist crime so great the Judaeo-Christian tradition did not once authorise it. The Iranian judiciary murders gays and Islamic State throws them from tall buildings to delight the faithful. The Book of Leviticus would approve. It says that men who have sex with each other “shall surely be put to death”.

Assad, Iran and Hezbollah engage in the mass murder of Sunnis. Isis returns the compliment and takes Yazidi, Shia and Christian women as their sex slaves. But then Moses commanded the Israelites to fall upon their enemies and kill everyone except “women that have not known a man by lying with him”. Those they could keep for themselves.

It may be objected that the New Testament is less gory that the Old. But Christ no more forbad slavery, rape, torture and genocide than did the Ten Commandments. Christians in power engaged in orgies of persecution of one another, of non-believers, of witches and of Jews. Indeed, the true Judaeo-Christian tradition was the 1,600-year tradition of Christians murdering Jews. What civilisation Judaism and Christianity possess came from the outside. They did not reform themselves, which is why calls for a Muslim reformation so spectacularly miss the point. Civilisation came from the battering that religion took from the Enlightenment, from sceptics, scientists, mockers and philosophers, who destroyed their myths and exposed the immorality of their taboos.