“It is a turning point,” said Emad Shahin, a scholar on Islamic law and politics at the University of Notre Dame who was in Cairo.

At the center of the debates is a new breed of politician who has risen from an Islamist milieu but accepts an essentially secular state, a current that some scholars have already taken to identifying as “post Islamist.” Its foremost exemplars are Prime Minister Recep Tayyip Erdogan’s Justice and Development Party in Turkey, whose intellectuals speak of a shared experience and a common heritage with some of the younger members of the Muslim Brotherhood in Egypt and with the Ennahda Party in Tunisia. Like Turkey, Tunisia faced decades of a state-enforced secularism that never completely reconciled itself with a conservative population.

“They feel at home with each other,” said Cengiz Candar, an Arabic-speaking Turkish columnist. “It’s similar terms of reference, and they can easily communicate with them.”

Mr. Ghannouchi, the Tunisian Islamist, has suggested a common ambition, proposing what some say Mr. Erdogan’s party has managed to achieve: a prosperous, democratic Muslim state, led by a party that is deeply religious but operates within a system that is supposed to protect liberties. (That is the notion, at least — Mr. Erdogan’s critics accuse him of a pronounced streak of authoritarianism.)

“If the Islamic spectrum goes from Bin Laden to Erdogan, which of them is Islam?” Mr. Ghannouchi asked in a recent debate with a secular critic. “Why are we put in the same place as a model that is far from our thought, like the Taliban or the Saudi model, while there are other successful Islamic models that are close to us, like the Turkish, the Malaysian and the Indonesian models, models that combine Islam and modernity?”

The notion of an Arab post-Islamism is not confined to Tunisia. In Libya, Ali Sallabi, the most important Islamist political leader, cites Mr. Ghannouchi as a major influence. Abdel Moneim Abou el-Fotouh, a former Muslim Brotherhood leader who is running for president in Egypt, has joined several new breakaway political parties in arguing that the state should avoid interpreting or enforcing Islamic law, regulating religious taxes or barring a person from running for president based on gender or religion.

A party formed by three leaders of the Brotherhood’s youth wing says that while Egypt shares a common Arab and Islamic culture with the region, its emerging political system should ensure protections of individual freedoms as robust as the West’s. In an interview, one of them, Islam Lotfy, argued that the strictly religious kingdom of Saudi Arabia, where the Koran is ostensibly the constitution, was less Islamist than Turkey. “It is not Islamist; it is dictatorship,” said Mr. Lotfy, who was recently expelled from the Brotherhood for starting the new party.