The two sisters wear Islamic head scarves and say they have no problem with their secular friends and classmates, who don't. Yet on the streets, in classrooms and along the hallways of apartment buildings in the cramped Fatih district of Istanbul, Deniz and Daria Ker remind them every now and then that they'll stew in a fiery hell if they don't cover up.
"We say, 'If a single strand of hair comes out and a man sees it, you'll be damned for 40 years,'" says Daria, an 18-year-old high school student, a white head scarf covering her head as she helps her 20-year-old sister work the cash register of a children's clothing store. "It's a must in our religion."
In much of Turkey, observant and secularist Muslims live largely apart, inhabiting different enclaves within big cities like Istanbul and in different regions of the country.
But in Fatih, an ancient district that's home to about 450,000 people near the center of Turkey's economic and cultural capital, members of the two main cultural camps are side by side. They interact, sometimes uncomfortably, every day.
For centuries, Istanbul has been a crossroads of East and West, straddling the European and Asian continents on either side of the Bosporus strait. Fatih, a mostly working- and lower-middle-class district on the city's European side, is a microcosm of contemporary Turkey. As a growing and prosperous Muslim middle class rises to take the helm in Turkey, Fatih's fate also may be a test for the country's future, and possibly that of the West as it attempts to integrate Islam into its ethnic and religious landscape.
"Turkey is one country, but there is a polarization," says Nilufer Narli, a professor of sociology at Bahcesehir University in Istanbul, who has studied Fatih since the late 1990s. "The polarization isn't new, but it has been sharpened within the last few years."
In Fatih, the observant and secular share new five- to10-story apartment buildings as well as the ancient streets. They shop at the same large chain clothing stores and corner groceries. They bump against one another on crosswalks, stare at the same store displays, negotiate over the price of tomatoes.
Every day, people here grapple with questions that have confounded politicians and social scientists, questions about the meaning of faith and of sovereignty over public spaces.
"The secularists lived with secularists for 150 years. Religious people lived with their own kind for 150 years," said Etyen Mahcupyan, director of the democratization program at the Turkish Economic and Social Studies Foundation, an Istanbul think tank. "Now there is a social sphere where they are tangential to each other. They are touching each other."
Cheap rents and proximity to the center of the city lured migrants from Turkey's Anatolian interior to Fatih, Istanbul's oldest neighborhood. Some of the wealthier and more secular residents moved to more exclusive enclaves, but many also remained.
A low-level cultural war between the country's surging Islamic past and its century-old commitment to secularism unfolds daily on Fatih's streets. It is a conflict between the "closed," those families whose women wear the hijab, or head scarf, and publicly abide by a strict interpretation of Islam, and the "open," the secular Turks who dominated the country politically and economically during the 20th century.
Class resentment fuels the tensions. Cosmopolitan Istanbul residents speak of Fatih as though it were Kandahar, a backwater of extremists huddled together. "Those people live together because they want to live that way," said one resident of Bebek, an upscale northern suburb of Istanbul.
The subtle struggle plays out in how one presents oneself: in the cut of an outfit, the length of a woman's skirt, the growth of stubble on a man's face. It is felt in the duration of a stare at a scantily clad or heavily covered-up woman, or the rumble of an imam's voice on the mosque loudspeaker as he recites a particularly moralistic passage from the Koran.
Residents say there's no overt antagonism between the two groups, no violence or clashes on the street. Somehow, they say, they all work, walk and play next to one another, if not always with one another.
But what is unmistakable is a cultural chauvinism that is clearly practiced by the Islamists, one that frightens and angers many secular Turks who are worried that their cultural identity is being worn away.
"There's no harsh pressure," Hossein Avnikar, a local official, said of complaints by secular women that they're constantly asked to cover up. "They say it. But they say it very sweetly."
The observant speak of masoulieh tabliq, a Muslim's responsibility to promote the faith, to get the unbelievers to believe and the less-observant to practice their religion more strictly. As Maksut Senocak, a religiously observant 50-year-old builder explained during a tea at one of the local cafes: "Of course they would tell each other what is sin, because our prophet and imams at the mosque are saying that we should."
The neighborhood can be a cultural minefield, especially for secular women. Mediha Hasakin, 30, an accountant who has lived in Fatih her entire life, said she has begun to cover her shoulders or wear a jacket when she walks in or near certain areas, especially Carsamba, a neighborhood of 50,000 described by many as Istanbul's most conservative.
"We're being careful, up on the hill," she said, gesturing toward the warren of narrow streets where men sport lengthy beards and skull caps, women dress in all-covering Arabian-style black abayas and restaurants remain shuttered in the daytime during the dawn-to-dusk fast of the Muslim holy month of Ramadan.
"Someone will come up to you and tell you, 'Don't let your hair show,'" she said.
Gulcin Dugrul, 22, has stopped wearing dresses when she walks her 1-year-old boy. She veers to the other side of the road when she's about to pass teahouses filled with bearded, religiously observant men.
"They tell me on the streets, 'Why are you open?' They say, 'Get dressed, my girl,'" she said.
Even women wearing the hijab are told to cover up more, or wear darker clothes, she said. That has convinced her that there's no pleasing the Islamists.
"I tell them, 'It's not your business. Everyone is responsible enough to herself.'"
Some parts of Fatih seem a continent away from the boozy, freewheeling scene of Istiklal Street or Taksim Square, Istanbul's center of tourism and nightlife. Very few shops or cafes sell alcohol, especially anywhere near Carsamba.
"It would take a brave heart to sell alcohol here," said Adem Ozbektas, a local official.
Huge billboards along Vatan Street advertise Islamic fashions aimed at the new Muslim middle class. New stores sell Islamic swim and sports wear. Wedding halls offer separate facilities for men and women.
Secularists feel that their freedom to speak and act is being threatened by social pressures.
"Prosperity has only made the Islamists bolder," said Kader, a 64-year-old jeweler who asked that his last name not be published. "They're manipulating people. They say, 'God will do this and God will do that.'"
Turkey's secular elites marginalized the more conservative and rural underclass until very recently. And, socially, they still do. Despite their growing economic power, the new Muslim middle classes, many of them relatively recent arrivals from Turkey's vast Asian interior or the Black Sea coast, say they feel cultural discrimination.
"There are people who look down at us," Deniz Ker said at the cash register of the clothing store. "There are people who don't want to be friends with us because we're closed. The open ones are embarrassed to be seen with us."
But there are some signs that there is room for compromise.
According to polling by the Turkish Economic and Social Studies Foundation, no more than 5% of Turks are hardcore Islamists and 7% strident secularists. Most fall in the middle, presumably looking for common ground.
"Thirty years ago, when people were ignorant, the believers lived on one side and the nonbelievers lived on the other side," said Osman Keskin, 64, the proprietor of a cafe, who has lived in the neighborhood since 1957. "Now, the people don't live past each other. It's a mosaic."
Zeinap Joske and Kubra Aryigit, both 14, have been best friends since childhood, living in the same Fatih apartment building and attending the same schools. The teenage girls walk arm in arm through the streets, Joske wearing a head scarf and overcoat, and Aryigit's long blond curls hanging freely on her shoulders.
"We fight occasionally, but only about little things," Kubra said. "We respect each other's religious views. And we would never try to impose our ideas on each other."