The Green-Social Democrat government in the state of Baden-Württemberg wants to anchor "acceptance of sexual diversity" in its 2015 education plan.

This sounds like a non-story. Sexual education has long been a part of the curriculum; equality laws forbid discrimination against people on the basis of their sexual identity. Teachers should be promoting integration and tolerance, while homophobia remains a serious problem in many schools.

Even so, the plans have sparked a fierce debate. Online petitions in favour and against are competing for signatures, political parties are arguing, the churches are mobilizing and horrible words are being used (Indoctrination! Homophobia!).

But the core of the problem is barely being discussed. This starts with the fuzzy terminology being used. What exactly is sexual diversity? A general definition would mean all forms of sexuality in which adults freely engage with each other.

And this must not only include gay, lesbian, bisexual and transsexual life- and love-practices, but also sadomasochism, polygamy, polyamory and incest.

Everything goes

Why must homosexuality be accepted, but polyamory (so long as it's accepted by all those involved) not? Polyamorists talk of "open, loving, stable sexual relationships between more than two adult people". What's wrong with that?

And the ban on incest is difficult to justify without resorting to traditional norms. An undisputed acceptance that disabled people have an unlimited right to sexuality prevents us talking about the increased risk of inherited illness.

Added to this comes a potential clash of values with the constitution. Marriage and family are particularly well protected in Germany in Article Six of the Basic Law. They enjoy an exceptional role as a normative lifestyle. Thus the ideal are gay and straight marriages which are based on families – meaning children.

All other lifestyles are encompassed in the freedom of self-expression of every individual, but teachers following the constitution cannot portray them as equal to marriage and family. Does this contribute to greater acceptance?

Intercultural dimensions

And finally, the intercultural dimension. Migrant homophobia, in particular among young people with Arabic, Turkish and Russian roots, is more prevalent than among natives. Muslim and Orthodox Christian religious teachers generally regard homosexual activity as sinful.

This means many young migrants would be plunged into a deep identity and value crisis by an educational system preaching acceptance of sexual diversity.

There would be a conflict between the morals at home that they learn from their parents, and the school morality.

In practice this would mean that the authority of the parents as well as that of the teachers would be undermined. And this strengthens the feelings of many migrants that integration is always just the imposition of the Leitkultur and the denial of cultural autonomy.

Accept sexual diversity? Sounds good. But those who look more closely have to think again.