In Germany’s secular society, religion in general, and Islam in particular, is regarded as an atavism, a relic from a premodern era from which the country has luckily matured. Renunciation and deliberate submission, common elements of religion, throw the average German hedonist into a state of panic (unless they are part of a no-carbs diet or yoga routine). Why would anybody in her right mind refrain from eating or wrap a scarf around her head in the summer? Whoever does so — like Ms. Ulusoy — must either be out of her mind or the victim of some dark power.

Neutrality laws like those in France, Belgium and some of Germany’s federal states also draw from a certain tradition of interpreting religious freedom. In Europe, it tends to be defined as the freedom from religion — not the freedom to practice faith. This approach is deeply rooted in our history, a lesson from the close alliance between monarchy and church, and countless bloody religious wars.

In the rearview mirror, a strict laicism makes sense. But up ahead, there’s a multicultural Europe that requires more room, not less, for religious expression.

At the heart of Europe’s neutrality laws, there’s a bitter misunderstanding: Being antireligious is not neutral. It doesn’t heal the cultural divide that can come with immigration but emphasizes it. Just look at France.

Since 2004, French students have been prohibited from “ostentatiously” showing or wearing religious symbols at school. Since 2011, the burqa has been banned from streets and public places.

Since the prohibitions, the country has engaged in a petty war over inches of visible skin. Just a few months ago, a Muslim student in the town of Charleville-Mézières was suspended because she was wearing a black skirt that went to her ankles. The girl usually wears a head scarf, but takes it off before school. A local newspaper reported the case, and a nationwide Twitter debate broke loose. The country’s minister of education admitted that a skirt was not a religious symbol per se — but lauded the principal for reinforcing neutrality.

Fortunately, it has become less likely that Germany will follow France down the path of interdiction. In March, the Constitutional Court overturned state legislation banning head scarves for teachers. In its verdict, the court said that the constitutional neutrality of the state “promotes religious freedom for all denominations alike.”

Still, the idea of a postfaith German “Leitkultur,” or common culture, is not dead. Every couple of months a politician from the ranks of the conservative Christian Democratic Union calls for banning the burqa. And Betul Ulusoy’s will certainly not be the last contested head scarf. She still has a lot to do, starting with showing that there is no contradiction between using your head and wrapping it in a scarf.