TEHRAN — IN the 1970s, the words of Iranian sociologist Ali Sharaiti had a profound impact on the role of Shiite Muslim clerics in Iran.
Dr. Sharaiti taught that religion is a total political, social, and economic ideology and that the Islamic clergy should be involved in running the country. Many Iranians say it was his philosophy that motivated the clergy in its revolt against the pro-Western regime of the US-backed shah in 1979.
But today another academic -- a teacher of theology at the Tehran School of Theology, Abdul Karim Soroush -- is challenging the Islamic clergy. Just like Sharaiti, Dr. Soroush's teachings are based on Islam. Sharaiti, who lived in a different era, had sought to revolutionize the society against social injustice through Islam.
Soroush is now challenging the monopoly of the clerics resulting from the 1979 revolution by providing a philosophical religious basis for democracy.
The British-educated philosopher preaches his ideas through the Tehran quarterly magazine Keyan, which means essence, and through a series of lectures at Tehran University.
But last month, Soroush was reportedly visiting at a university in Malaysia. Rumors flourished in Tehran that Soroush was asked to leave for a few months by authorities threatened by his ideas. His supporters deny such reports.
Soroush's theory is that there is not one absolute interpretation of Islamic principles or thought, but many. And that neither one person nor one group of clerics can claim the right to one single interpretation of Islam.
''According to Soroush, any interpretation by an individual, or cleric, regardless of his scholarly and religious level, is largely influenced by that person's social conditions, upbringing, background, and all kinds of socioecononmic, psychological, and political factors,'' explains Naser Hadian, a political scientist at Tehran University.
''Consequently, there cannot be a single interpretation of Islam that could be seen as the absolute truth because understanding of Islam is relative,'' adds Dr. Hadian, who knows Soroush and follows his lectures.
Soroush's arguments sound abstract, but they challenge the concepts and laws the Islamic clergy have imposed in the name of sharia, Islamic law -- everything from claiming ultimate political and religious authority to ruling that women must wear the hijab, or head scarf.
Most significantly, however, he provides an understanding of Islam that is compatible with democracy. In his views, individuals cannot be coerced into practicing the Muslim faith -- they have to be free to ''submit to God'' -- which is what ''Islam'' means in Arabic.
''Undoubtedly pluralism is a precondition and a consequence of Soroush's thought,'' Hadian says. ''If you subject religion to a multiple of interpretations, that gives you a substance for pluralism,'' agrees Hadi Samti, another political scientist at Tehran University.
Yet perhaps the most dangerous impact of Soroush's thought for the ruling Iranian clergy is his implied call for the separation of church and state. According to Soroush's written teachings, religion cannot and should not be transformed into an ideology. He says if it is, it is likely to become extinct as a religion.
Soroush argues that if religion is turned into an ideology or political party, it then would become accountable for the political and social shortcomings of the system. Soroush believes religion should stay above that.
Soroush supporters, including academicians, intellectuals, dissidents, and even some clerics, are cautious not to explore this loaded and explosive aspect of his theory.
Some in Iran have already likened him to Martin Luther, arguing that he will bring about reformation that will enable Islam to adapt to the modern era.
Soroush's ideas are expected to have a profound impact on Islamic thought in the whole Middle East. The practical implications of his ideas on Iran, however, will be even more crucial to the course that Islamic thought will take in the region.