The question of whether Muslim women can wear head scarves in European state schools keeps coming back. A French school recently suspended two girls for covering their heads, while Germany ruled in favor of a teacher who insisted on wearing her head scarf in class. Cases like the one in France have been portrayed as a defense of the secular state — the need to keep overt religious symbols out of state schools. This seems a false pretext. Following the dress or dietary codes of one's faith is an exercise of freedom of conscience so long as the exercise does not amount to proselytizing or otherwise infringing on the freedoms of others.

The laws, their rationale and their enforcement differ from country to country, even school to school. But the fact is that any such regulation is inherently discriminatory because the targets are likely to be members of faiths that mandate outward signs. The scarf of a Muslim woman, the skullcap of an observant Jew and the turban of a Sikh cannot be concealed.

In France, Europe's most adamantly secular nation, the constitution gives schools power to ban any religious symbol worn as an "act of pressure, provocation, proselytism or propaganda." But that provision was framed in a long and bitter struggle between church and state. The real motive behind the objections to head scarves too often appears to be resentment of the growing population of Muslims, sometimes augmented by feminists who see the scarf as a symbol of women's subjugation.

These are not valid motives. The purpose of separating church and state in schools is to liberate students from the pressures and taboos of sectarians and ideologues. Of course, wearing a head scarf may well be a political statement, and it may even inspire schoolmates to explore radical Islam. But to presume that every devout Muslim is a radical is a false and dangerous notion. And the battle with extremism cannot start with the suppression of personal religious expression in schools; that is not only a violation of fundamental freedoms, but also a good way of pushing ideas underground and ensuring that they become seriously dangerous.