Thousands of people joined a secular rally in Tunis on Saturday to protest violence by the Salafis. Many in the cosmopolitan city now worry about what the revolution they embraced might unleash.  TUNIS — The insults were furious. “Infidel!” and “Apostate!” the religious protesters shouted at the two men who had come to the courthouse to show their support for a television director on trial on charges of blasphemy. Fists, then a head butt followed.  When the scuffle ended a few minutes later, Tunisia, which much of the Arab world sees as a model for revolution, had witnessed a crucial scene in what some have cast as a gathering contest for its soul.  “We’re surrendering our right to think and speak differently,” said Hamadi Redissi, one of the two men, still bearing a scab on his forehead from the attack last week.  The challenges before Tunisia’s year-old revolution are immense — righting an ailing economy, drafting a new constitution and recovering from decades of dictatorship that cauterized civic life. But in the first months of a coalition government led by the Ennahda Party, seen as one of the most pragmatic of the region’s Islamist movements, the most emotional of struggles has surged to the forefront: a fight over the identity of an Arab and Muslim society that its authoritarian leaders had always cast as adamantly secular.  The popular revolts that began to sweep across the Middle East one year ago have forced societies like Tunisia’s, removed from the grip of authoritarian leaders and celebrating an imagined unity, to confront their own complexity. The aftermath has brought elections in Egypt and Tunisia as well as more decisive Islamist influence in Morocco, Libya and, perhaps, Syria. The upheaval has given competing Islamist movements a chance to exert influence and define themselves locally and on the world stage. It has also given rise to fears, where people in places like Tunis, a seaside metropolis proud of its cosmopolitanism, worry about what a revolution they embraced might unleash.  An opposition newspaper has warned darkly of puritanical Islamists declaring their own fief in some backwater town. Protests convulsed a university in Tunis over its refusal to let female students take examinations while wearing veils that concealed their faces. Then there is the trial Mr. Redissi attended on Jan. 23, of a television director who faces as many as five years in prison for broadcasting the French animated movie “Persepolis,” which contains a brief scene depicting God that many here have deemed blasphemous.  The trial was postponed again, this time until April. But its symbolism, precedence and implications infused a secular rally Saturday that drew thousands to downtown Tunis in one of the biggest demonstrations here in recent months.  “Make a common front against fanaticism,” one banner declared.  Tunisia and Egypt are remarkable for how much freer they have become in the year since their revolts. They may become more conservative, too, as Islamist parties inspire and articulate the mores and attitudes of populations that have always been more traditional than the urban elite. Some here hope the contest may eventually strike a balance between religious sensitivity and freedom of expression, an issue as familiar in the West as it is in Muslim countries. Others worry that debates pressed by the most fervent — over the veil, sunbathing on beaches and racy fare in the media — may polarize societies and embroil nascent governments in debates they seem to prefer to avoid.  “It’s like a war of attrition,” said Said Ferjani, a member of Ennahda’s political bureau, who complained that his party was trapped between two extremes, the most ardently secular and the religious. “They’re trying not to let us focus on the real issues.”  Nearly everyone here seems to agree that “Persepolis” was broadcast Oct. 7 on Nessma TV as a provocation of some sort. Abdelhalim Messaoudi, a journalist at Nessma, said he envisioned the film, about a girl’s childhood in revolutionary Iran, “as a pretext to start a conversation.” But many in Tunisia, both pious and less so, were taken aback by the brief scene in which God was personified — speaking in Tunisian slang no less. A week later, a crowd of Salafis — the term used for the most conservative Islamists — attacked the house of Nabil Karoui, the station’s director, and he was soon charged with libeling religion and broadcasting information that could “harm public order or good morals.”  The trial, which Human Rights Watch called “a disturbing turn for the nascent Tunisian democracy,” was originally scheduled for Nov. 16, then postponed until January.  On Jan. 23, crowds gathered outside the colonnaded courthouse, along a sylvan street in Tunisia’s old town, known as the casbah. Tempers flared and, in a scene captured on YouTube, Mr. Redissi and Zied Krichen, the editor of the newspaper Al Maghreb, tried to leave.
A blasphemy trial in Tunis symbolizes an emotional struggle, with implications for the Arab world, playing out with the rise of Islamists after the end of a secular dictatorship.