Because of its dark history in Germany, genetic tinkering with human reproduction is a matter of hot debate here - hotter than in any other country in Europe and, perhaps, the world.
Lately, the temperature has jumped even higher, specifically concerning whether would-be parents should be allowed to use a medical procedure that, doctors say, eliminates the risk of hereditary diseases being transmitted to offspring.
The procedure, called pre-implantation genetic diagnostics (PGD), is forbidden in Germany but has been used in fertility clinics elsewhere since its invention in 1989.
The latest firestorm erupted last month at a Berlin conference on human reproduction, when researchers released a survey indicating that 4 in 5 Germans approve of PGD to prevent genetic diseases.
Charges of bias in the survey - and countercharges of thwarting the public's will - have been flying ever since. Feelings on the matter run so deeply that one politician, who defends the law that bans PGD, characterized the import of the debate this way: "If we break [this law], then we break the basis of our society."
The technique in question, doctors say, can prevent diseases that otherwise persist in families for generations. Muscular dystrophy and cystic fibrosis, two terminal conditions for which medical science has not found a cure, are among the diseases that can be prevented via PGD, they say.
The doctor's role, something like that of a bouncer guarding a select nightclub, is to ensure that a fertilized egg containing the troublesome mutation never gains entrance to the womb.
Though it takes the fun out of conception, the most efficient method is to collect eggs from the mother and inject each with a sperm cell from the father. After three days' growth, a fertilized embryo is big enough so that doctors can remove a single cell for analysis without harming its development.
At this point, doctors can test the cells to see which of the embryos, if any, has inherited the mutation. Embryos that test positive are discarded, and the rest are implanted in the womb. As with all in-vitro fertilizations involving multiple embryos, women are much more likely to bear twins or triplets.
But the likelihood of passing on the genetic disease, doctors say, is nearly zero.
PGD has been illegal in Germany since 1990, when the German parliament passed the Embryo Protection Law.
"There was a feeling that such new technologies required a strong national law because of fears of eugenics," says Heribert Kentenich, a member of Germany's national Board of Physicians.
Any manipulation of human embryos in Germany must pass a formidable legal gantlet, he says, "because a human embryo is considered a human being, and so it has human dignity."
The importance of protecting "human dignity" has been enshrined in the first paragraph of the German constitution since 1949.
One reason for this, of course, is historical. During World War II, the medical establishment was a Nazi stronghold, overseeing the forced sterilization of thousands of German citizens, not to mention far worse experiments carried out in concentration camps.
It's a history that has made Germany cautious about technologies that have any potential for eugenic abuse.
Emerging medical technologies, though, have made it increasingly difficult to decide what is and is not "human." While Germany holds PGD at arm's length, the rest of Europe, North America, and much of Asia have embraced it.
Consequently, German couples routinely travel abroad for "fertility tourism," visiting countries such as the Czech Republic where PGD is inexpensive and unregulated.
Dr. Kentenich is one who believes it's time to lift the ban, and he has been urging the government to reconsider its position.
Last year he helped organize the first large-scale survey on public attitudes toward PGD - the very survey that touched off the recent furor when its results were unveiled here last month at the meeting of the European Society of Human Reproduction and Embryology.
The findings seem to fly in the face of the consensus among politicians. A parliamentary commission reexamined the legality of PGD in 2002 - and unanimously decided to keep PGD strictly forbidden.
Most politicians believed the public was behind them, says René Röspel, a parliament member from the ruling Social Democratic Party (SPD) who chaired the commission.
"The majority of the public who took part in the discussion were against PGD," says Mr. Röspel although he acknowledges that the group might not have been "representative" of German public.
"I don't believe the results [of the new survey]," says Wolfgang Wodarg, another SPD member of the commission. "If you present questions in a certain way, you can make it seem Germans are in favor of the death penalty, which they certainly are not."
Even if the survey is accurate, Röspel says it does not sway him.
"I understand the desire of parents to prevent horrible diseases in their children," he says, but when it comes to deciding when PGD is permissible, "I do not believe it is possible to decide which diseases are horrible enough."
If PGD is allowed for one disease, "parents will say, 'But what about this disease?' And that's where the slippery slope begins."
Mr. Wodarg, for his part, is already disturbed that many German clinics abort fetuses to prevent Down's syndrome and, in some cases, harelip, which poses no threat to health.
Adds Röspel: "Modern medicine allows people with handicaps to enjoy long lives, so manipulating genetics is not the answer."
On the streets of Berlin, Germans voice a range of opinion - echoing the debate between fertility doctors and politicians.
"You can't give parents these choices, because if it becomes possible they'll want to control children's features, even sexual orientation," says Sabine Künzel, a lawyer.
At the other extreme, Oliver Redner, a high school physics teacher, favors legalizing PGD.
"Of course you need legal constraints, but I'm not afraid of eugenics," he says. "And if 80 percent of Germans really do agree, then the law should be changed. That's how democracy works.