A ban on circumcision in Germany has shocked the nation's Jews and Muslims. The right of parents to make decisions for their children is now under the spotlight.
A court ruling in Germany effectively banning circumcision has united Jews and Muslims in anger - and they are backed by the country's main medical association.
Muslims have warned that the devout will take sons abroad to be circumcised.
Jews have pointed out that attacks on Jewish religious rituals have been an unfortunate part of European history since the Roman times, and say they are dismayed by the latest ban. One Russian rabbi in Berlin to discuss the ban called it "perhaps the most serious attack on Jewish life in Europe since the Holocaust".
The German government has been stung by the reaction. Chancellor Merkel's spokesman said that circumcision must be possible in Germany - though he didn't say whether the law would be changed or clarified by a higher court.
The ruling by the district court of Cologne says circumcision "for the purpose of religious upbringing constitutes a violation of physical integrity".
The judgement added: "The child's body is permanently and irreparably changed by the circumcision. This change conflicts with the child's interest of later being able to make his own decision on his religious affiliation."
The case stemmed from a circumcision on a four-year-old Muslim boy who had to be taken to hospital when complications developed. That, unusually, put the case into the legal system and the doctor was prosecuted.
As the charge put it, the doctor "physically mistreated another person and injured that person's health by means of a dangerous instrument".
In the end, he was cleared. The court decided that circumcision was illegal but that the doctor couldn't have been expected to have known this. It had been done for so long that it seemed legal when - according to the court - it wasn't.
Because the doctor was cleared, there will be no appeal to a higher court, which means the soundness of the rest of the judgement will not immediately be tested.
This puts the medical profession in a great dilemma. Dr Frank Montgomery, the president of the German Medical Association, told the BBC: "It leaves doctors in a legal quagmire. We are convinced that circumcision is best performed under medical conditions by physicians in a hospital.
"This is obviously no longer legally possible so therefore we have to advise our physicians not to perform these operations because they run the legal risk of being taken to court."
Already, the Jewish Hospital in Berlin, which has been performing ritual circumcisions for 250 years, has stopped. Its medical director, Professor Kristof Graf said: "We have had to stop planned surgeries in five cases already where they were scheduled for circumcision and the families were completely destroyed and upset about this."
Despite its name, the Jewish Hospital performs ritual circumcisions on Muslims as well as Jews, in fact more of the former than the latter, largely because there are many more Muslims in Germany than Jews.
The rules of ritual circumcision are different for each faith. For Jews, it has to be done on the eighth day after birth (assuming the baby is healthy), but Muslims can wait longer.
So for Jews, the problem is more urgent. Circumcision is already performed by "mohels" - people designated as able to circumcise - but many prefer the safeguards which formal medical facilities provide.
A poll for Focus magazine found that 56% of those polled thought the judgement was right, compared with 35% against and 10% undecided.
But in the Jewish community, there is incredulity at the court's decision. Jonah Sievers, the Chief Rabbi of Lower Saxony, told the BBC that when he first heard, he "thought it was just impossible".
"Not to perform an ancient ritual is beyond the imagination. From ancient times onwards, there were certain times when there were decision by rulers to harm Judaism or to forbid or to weaken the Jewish religion, and one of them was to disallow circumcision, so it's not the first time and probably will not be the last time.
"Circumcision as the expression of the Covenant between God and his people is such an ancient and entrenched ritual. It's more than just a ritual. It's performed by Orthodox and Liberal Jews alike. It's a core part of the religion."
There has been outrage outside Germany, too, for example from Britain's Chief Rabbi, Lord Sacks - though he sees the ruling as a blow primarily directed at Muslims, with Jews as "collateral damage".
In Germany at the moment, there is a debate about the role of Islam in society, and the extent to which it is really a part of German life. People argue over how far society should tolerate rules particular to one group, Muslims in particular. It's not unique to Germany - in Britain, France and other countries, there's been debate about the veil.
Muslim groups are reacting cautiously to the court decision.
Mohammed Asif Sadiq, one of the leaders at the Katijah Mosque in Berlin, told the BBC the mosque didn't want to get involved in a public debate on a subject that provoked such strong emotions. "But in the long run it will be necessary to discuss it with politicians and with the court and even to ask the federal court to decide and make one law which is applicable for all," he said.
In the meantime, he felt, circumcision would continue but in less hygienic conditions. "One possibility is medical tourism so people with fundamental belief will just go to their homelands.
"I do not want small children who are born in Germany to move to another country, maybe a third-world country, where laymen who have no medical instruction cut their foreskins."
The defenders of the ruling say that it had nothing to do with religion - it was just an interpretation of the law. The court relied heavily on the opinions of a professor at the University of Passau in Bavaria, Dr Holm Putzke, who has written an article in the Legal Journal, a magazine for lawyers in Germany, applauding the ruling.
"After all the knee-jerk outrage has subsided, it is to be hoped it will set in motion a discussion about religiously motivated violence against children," he wrote.
Some newspaper columnists and editorials have also come out in favour of the ban. Matthias Ruch of the FT Deutschland , said: "The judgment is right - all protests to the contrary. The circumcision of young boys just for religious reasons is a personal injury. Muslims and Jews should decide themselves - but not before the age of 14".
Die Welt wrote : "The circumcision of Muslim boys is just as heinous as the archaic custom of the genital mutilation of little girls. It is an instrument of oppression and should be outlawed".
The court's ruling also touched upon the rights of parents to take decisions on behalf of their children. As the judgement put it: "There was no consent by the child, who was four years old at the time, and since the child was not old enough to understand the situation, there was no question of such consent being given."
But that, according to Dr Montgomery opens a can of worms. "How about piercing the ears of little children. Do parents have the right to pierce the ears of their little daughters?"
And what rights do parents have over their children's religion, he wonders: "With baptism in Christianity, you pre-construct the religious position of little children by baptising them.
"And I think our Constitutional Court has to decide if parents have the right to do this because this is the legal basis of the verdict which the court in Cologne has taken."
But this decision won't happen any time soon. It can take many years for a case to get to the Constitutional Court - and a test case is not currently even in prospect.
Listen to a rabbi and a Jewish man who has chosen not to circumcise his son on BBCRadio 5Live's Men's Hour at 21:00 on Sunday.