TEHRAN–Despite his turban and cloak, or perhaps because of it, Mohsen Kadivar is a “dangerous man” for the Islamic Republic of Iran.

The 41 years old cleric and confidant of President Mohammed Khatami trained at Iran’s best theological seminary and taught at some of the best universities in the country.

He was active in the Islamic revolution that toppled the shah 21 years ago and has written heavy tomes on Islamic philosophy and law. But that was before he was banned from teaching, before he was tried and sentenced to prison on charges of disseminating lies, defaming Islam and disturbing public opinion with his newspaper commentaries. In those commentaries, he suggested that the rule of the clerics had become as tyrannical as the rule of the kings. Now, after 18 months in prison, Mr. Kadivar is free – in a manner of speaking.  He was released in July but he is still banned from teaching.  He has been told that he faces new criminal charges, but he does not know what they are or when they will be filed.

Most of the reformist newspapers for which he wrote are closed.  Many of the journalists and clerics he counts among his friends are behind bars. And his attempt to give a speech with another leading reformer in the western industrial city of Khorramabad in August was blocked by armed vigilantes, causing riots that left a policeman dead and 100 people wounded.

“I truly believe in the things I have said,” he said in a three-hour conversation over sour cherry juice and platters of fruits and sweets.  “And I have already paid the price for it.” The bearded, midlevel cleric has refused to obey the dictum of the clerical court that convicted him – that he keeps his pen still and his mouth shut.

“I have no intention of listening to them,” he said.  “If they want to act against me again, this time it is they who will have to pay the price.”

Mr. Kadivar is dangerous because he is armed with one of the key weapons of the Islamic Republic: religion. Iran is locked in an intense struggle between reformers who want to make the system more responsive to the will of the people and conservatives, supported by armed street vigilantes, determined to keep their hold on power through their rigid interpretation of Islam. Mr. Kadivar comes to this ideological

Mohsen KadiVar, summing up his philosophy, said: “I believe democracy and Islam are compatible.”

Battlefield armed with Koranic verses and complex theological scholarship. When he talks of democracy, he does not demand the overthrow of the Islamic Republic and its replacement with a secular administration.

“I believe in a religious democratic state,” he said.  “I believe democracy and Islam are compatible.  But a religious state is possible only when it is elected and governed by the people.

And the governing of the country should not be necessarily in the hands of the clergy.  So what I support is the healthy state the reformers are promoting as an Islamic Republic, not what exists now.”

And what exists now, he continued, is a system in which one man, Ayatollah Ali Khamenei, has too much power, under a system of government known as the “rule of the Islamic jurist.”

Under the Iranian Constitution, Ayatollah Khamenei wields more power than the president, controls the national police and the security agencies, and appoints the leaders of the military, the Revolutionary Guards, the judiciary, national television and radio, and the foundations – ostensibly charitable – that control hundreds of companies and industries. But there are Islamic thinkers, Mr. kadivar included, who argue that the power structure has become distorted over the years.

Proof of that came last month, Mr. kadivar said, when Ayatollah Khamenei stunned the popularly elected Parliament – and much of the nation – when be decided that the Parliament would be prohibited from amending a restrictive press law. This is the meaning of the absolute authority,” Mr. Kadivar said, referring to the ayatollah’s position. “If one person is going to rule the same way the monarchy did, well, it was not the goal of the revolution to have one-person rule, even if he is a fair and knowledgeable man.’

In the current political climate in Iran, such criticism is breathtakingly bold.  Essentially, Mr. Kadivar is arguing that the official interpretation of Islam developed under the Islamic Republic is misguided. But he speaks so openly in part because that is what he is trained to do. The clerical system in Shiite Islam is a democratic, nonhierarchical, even rowdy one in which students are trained to speak their minds and challenge the authority of their professors.

Still, in clerical circles, Mr. Kadivar is an odd fit.  He began his studies in electrical engineering at the prestigious University of Shiraz, where he learned English, and turned to religious studies in the dusty, provincial holy city of Qum only after the secular universities were closed in the revolutionary crackdown.