It's only a light, almost flyaway, piece of fabric. But in Turkey, it has flown into a weighty debate - a debate that resonates across the Islamic world.
As in other nations, the head scarf is worn by many Islamic women in Turkey. But the country prides itself on keeping secularism in government - meaning that scarves aren't welcome in state buildings and institutions.
So when Islamist parliamentarian Merve Kavakci wore a head scarf to the opening of Turkey's parliament in April, heads turned. Some argued it was Ms. Kavakci's right to wear a scarf. Others saw it as a danger to the separation of religion and state.
The Kavakci affair has reinvigorated debate over wearing scarves in Turkish universities - another place they're banned. Caught in the middle are many women academics, who on the one hand are secular, on the other sympathetic to scarved students.
Turkey's women academics in knots over head scarves
Few women academics, however, are prepared to openly question the ban on head scarves, which are seen by those who wear them as a symbol of piety and modesty.
"For me, the head-scarved students are right," says one female lecturer at Istanbul University, which has seen the biggest demonstrations against the head-scarf ban. "They have passed their whole adolescence wearing the head scarf; they're used to it.... How can we suddenly tell them to take it off?"
Adds Cigdem Kagitcibasi, dean of the Science and Literature faculty at the private Koc University: "You can't stop a head-scarved girl at the university gate. These girls are covered up when they go to the [religious] Imam Hatip schools at age 11, then when they come to university at 20 we say: 'Uncover yourself!' "
Professor Kagitcibasi, an outspoken secularist, believes the problem stems from policies of the 1970s and '80s, which saw the formation of an openly religious political party and the expansion of religious schools.
Gul Bakus, an associate professor in Istanbul University's Communications faculty, says she and other teachers can easily tell the difference between students who are wearing head scarves for purely political reasons and those who do so out of tradition. "The ones who wear it for political reasons are always the first to remove their head scarves when they're told to," she says.
"But it's more difficult for the others - and they are among the best students, serious and always asking questions."
Even before the head scarf was banned outright in universities, teachers were aware of subtle discrimination against openly religious students. A university teacher who preferred not to be named says: "We were expected to be available to our students to discuss their problems ... but when I gave equal time to my head-scarved students, I noticed that my colleagues were regarding me with suspicion.... There were whispers that I was pro-Islamist."
She adds that although lecture times were often changed to fit in with students' requests, there was an unofficial rule that teachers shouldn't reschedule classes to allow students to attend Friday prayers.
This kind of pressure has fueled protests by Islamists against what they see as discrimination - even violation of human rights. But secular women have their own reasons for questioning the commitment of the Islamists to human rights: Many professional women who oppose the head scarf do so because they see the Islamist movement as a threat to the freedoms won for women in secular Turkey. They point to the regimes of nearby Iran and Algeria as examples of Islamic oppression of women.
Some feel that the Islamic threat in Turkey has been exaggerated. Edipe Sozer, an associate professor at Istanbul University, thinks the row over head scarves has diverted attention from more serious problems in the Turkish education system. "When students graduate from high schools they just don't know enough," she says. "And there are also serious financial problems. University teachers aren't paid enough, and the students have financial problems too."
NURAY MERT, a former teacher at Istanbul's Bogazici University, who has written extensively about Islamic politics in Turkey, describes a class of Westernized Turks whose self-image as members of a modern society is disturbed by the sight of women wearing head scarves. "To be 'civilized' you have to look like a Western person - and you have to see your society as civilized," she says.
As Mert points out, clothing has always been a serious political issue in Turkey, at the heart of debates about modernity and Turkey's relations with the West. When Sultan Mahmut II wanted to modernize the Ottoman Empire in the early 19th century, one of his first moves was to introduce Western-style Army uniforms.
A century later, in the early years of the Turkish republic, Mustafa Kemal Ataturk banned the fez, the red felt hat then worn by most Turkish men - part of sweeping moves to do away with Islamic traditions. The ban caused widespread protest, and a number of persistent opponents were even executed.
Ataturk wanted to create a modern society, and for him this meant one in which women played a more active role. He encouraged his adopted daughters to enter traditionally male fields: One became a pilot with the Turkish air force, another a professor of history.
Today's head-scarf controversy is the direct descendant of these earlier events. It persists despite opinion polls that suggest most Turks want to live in a secular state but are comfortable with the idea of female students wearing head scarves. But because the issues involved touch at the core of Turkish identity, this moderate view rarely finds expression at the highest levels of Turkish politics.