A quarter-century has passed in Iran since the revolution of February 1979. The election of a new president next month will likely signal the end of the 'third republic' ushered in by the election of President Mohammad Khatami on a reform platform in 1997 - the first and second being the reign of the Ayatollah Khomeini and the era of consolidation under Hashemi Rafsanjani respectively. What will come next? To answer this question ' which goes far beyond the mere identity of the next president ' it's necessary to understand how 26 momentous years have changed Iran as a country and Iranians themselves.

The 'generation of the revolution', to which I belong, is in its 50s and 60s now. Many of us were actively involved in the revolution of 1979, and heavily influenced by the political discourses of the 1960s and 70s. Many have occupied every position of power in the country and don't want to step aside or open the way for others, not just in government but in opposition too.

We were followed by a 'generation of war': people who came to maturity during the Iran'Iraq war, whose ideals were shaped by it and who were prepared to sacrifice everything. The purity of their commitment has since given way to disillusionment and passivity.

And then there is the generation in their teens and 20s ' the majority of the country's population. They are our children but they know little and care less about the revolution or the Shah. You had your revolution, they say, but we have a different agenda. We want jobs. We want comfort. We want life. We want happiness.

This post'revolutionary cycle has seen a profound social transformation.

First, there has been a vast increase in population, doubling since 1979 to 69 million in 2004. Iranians are increasingly city'dwellers: the urban population is approaching 70 per cent ' at least half of them in the capital, Tehran. This is a striking change in a country where the vast majority of people historically worked on the land.

Second, for the first time in Iran's history the majority of the population can read and write. Around 92 per cent of the young are literate. There has also been an expansion of university education, and it is significant that more than 61 per cent of all university students are girls.

Third, Iranians are communicating with each other more than ever before. There are 3'5 million internet users in Iran ' perhaps the highest number in the Middle East. The young generation in particular is online and blogging; there are 60,ooo'70,000 weblogs, making Persian the fourth most'used weblog language. Internet caf's abound.

Over 3 million homes have satellite television ' and the average Iranian family has 4.6 members. These people can watch Voice of America, CNN, BBC World, and over 700 other stations. BBC radio has more than 7.5 million listeners in Iran; the BBC's website has more than 250,000 Iranian visitors every day. The most popular newspaper in Iran has a circulation of around 450,000.

All this is a window on the outside world for Iranians. The regime tried to interfere with satellite reception in Tehran two years ago, but the effort was difficult, expensive and controversial. While it still jams certain shortwave frequencies and blocks some websites, it's too late to close the floodgates: Iranians have opened their minds to the world.

This is paralleled by the fact that Iranians are travelling more than ever. Around 2 million Iranians live outside Iran ' mostly in western Europe, Canada, and the United States, with large numbers in Japan too. Every summer about 200,000 Iranians travel abroad, and approximately 400,000 Iranians return for a visit. There is an active conversation going on among people inside and outside Iran about the country's future.

One of the topics of conversation is the fact that, since the revolution, Iranians have found it difficult to acquire foreign visas, leading them to ask what it is their government has done to make the world so hostile to them.

Finally, there has been an explosion of new ideas in Islamic intellectual life. It started during the second republic with a circle of intellectuals engaged in reformist theology and quickly spread to university students.

The tired pre-revolutionary split of Iran into four distinct political groups (Marxists, monarchists, nationalists, and Islamists) is giving way to a new paradigm, one which I, as a member of the generation of the revolution have experienced first-hand.

I went from being Deputy Minister for Heavy Industry and president of the Industrial Development and Renovation Organisation in the mid-eighties to realising, after the death of Imam Khomeini, that the revolution had turned into a kind of fascism in the Islamic Republic of Iran.

I re-entered the arena of politics in 2001 with the purpose of starting a conversation, especially with students. From the start I argued that the problem was Iran's constitution and the laws that flow from it, and changing them was a first, necessary step towards real democracy. With widespread dissatisfaction about the way the country is governed, and the overwhelming majority of young Iranians against the regime, the situation has become dangerous.

Under the current constitution the presidency means nothing. President Khatami possesses no real power. So the goal must be to change the constitution and make the position of a democratically elected president meaningful.

My campaigning soon made me a target, and in March 2003 officers of the Ministry of Intelligence arrested me at home. I, along with more than 800 university students, was charged with anti-regime propaganda . We were eventually released thanks to protests and vigils held at several universities, but the accusations of endangering national security have continued, based on nothing more than an interview I had given to a Radio France broadcaster said by the regime to belong to a pro-democracy association in France controlled by the CIA.

None of these experiences have stopped or will stop me from expressing my own ideas about what Iran needs: a new intellectual and political paradigm to break the absolutist and authoritarian system which has resulted in a fascist version of Islam in Iran, where everything has to be unified, singular, one: a total state. The regime even uses its own version of the Nazi Party's 'brown shirt' militia. The Revolutionary Guards, also known as 'white shirts', are present at every demonstration in Iran, violently attacking opposition groups.

But things are really changing. 'It' has happened. The promise of democracy has surfaced.

A reformation movement based on four principles ' democracy, human rights, civil society and involvement in the international community ' is on the march. This is something much wider and deeper than the reform process of President Khatami, which is effectively dead.

The impossibility of reform became apparent within two years of his election: under the existing constitution of the Islamic Republic, the supreme leader, not the president or parliament, is all-powerful. He can ratify everything and veto anything. Further, no law, statute, or order in the country can be against Islam, as interpreted by the appointed Council of Guardians and ratified by the supreme leader.

Under these circumstances democracy is impossible. The nature of the regime is essential Iran's problems , and so it must be changed. This is the lesson of Khatami's failed reforms.

So what is to be done? How can the reformation movement succeed where the reform process failed? The answer is to mobilise civil society behind a referendum campaign to create a new constitution. Changing the constitution is the key to democracy.

To this end a campaign has begun, calling for a referendum on the constitution. More than 35,000 people ' including 300 prominent writers, scientists, and intellectuals ' have signed a petition, despite efforts by the regime to silence us.

Although the regime will almost certainly try to block a referendum before it can be put to a ballot, there is a chance that popular pressure will prevent this in the same way that it has secured the release of reform activists in recent years.

Already everybody ' university students, families, taxi-drivers ' is talking about the referendum. Coordinating all this support behind the key aims of the plan is essential and will likely involve civil resistance.

In this regard, we are studying the experiences of other countries. The 'velvet revolution' in Czechoslovakia and Ghandi's satyagraha movement in India are only two examples.

It's difficult, maybe impossible, to persuade Iranians to sit down and be beaten and attacked without resisting. But we need non-violent action ' not revolution. In the revolutionary period, I was glad to see hatred of the Shah's regime, because it created and fuelled a revolution. But our project now is democracy. This means total openness to all points of view. When we announced that we wanted to hold a referendum on our constitution, we said that all groups were welcome to join us. Democracy requires this. Why exclude anyone?

Among our supporters are monarchists, even the son of the Shah. The monarchists say that they believe in parliamentary democracy, and that any Shah would only be the symbol of the country.

The referendum movement will need international support as well ' moral and organisational, though not financial: the danger of compromising ourselves by accepting money from a foreign government is too great.

Another source of foreign support might be from intellectuals, writers, artists, poets, playwrights, singers, novelists, philosophers. If they backed the referendum movement, it would help Iranian people gain the self-confidence they need.

This psychological dimension is crucial. Iranians believe that for any movement to be successful it must have the support of the international community. This is the first time in our recent history that Iranians have thought this way. The reason is the extent of power concentrated in the hands of the regime. It can harass everybody, close down shops, shut newspapers, block websites. Many Iranians feel opposition is useless in the face of this, so they want international help.

The support of western intellectuals would be especially important to our young generation. So far, leftist thinkers and writers have paid little attention to Iran. In any case, anti-Americanism, anti-westernism, anti-imperialism doesn't speak to our struggle. Young Iranians are reading the work of Isaiah Berlin, Karl Popper, Hannah Arendt. These thinkers are all available in Persian.

My generation thought about revolution and nothing more. But now Iranians are thinking about liberalism: Kant and neo-Kantianism. A new generation of Iranian scholars has studied the philosophy of science and religion. As a result, new ideas are emerging about a theme that figures centrally in Iran's national conversation: the conflict between tradition (not just our religion, Islam, but our poetry and literature, our rituals and culture) and modernity.

The place of Islam itself in our public life is central to the task of bridging this conflict. The strongest motivation for me is Islam itself. But precisely because I am a deeply religious person, I am also a secularist who believes in the separation of state and mosque.

In Iran we need a minimal theory of religion, not the maximum theory the Islamic Republic employs. A minimal theory of Islam or religion is the opposite of Islamism. When President Khatami started to argue for a religious democracy, he showed that he understands neither civil society nor democracy. Democracy is democracy.

This regime has done so many bad things to our country in the name of religion. As a result, young people in Iran are turning away from religion. If that's Islam, they say, we don't want it. So the divorce between Islam and the state is not only for the sake of human rights and democracy, but for Islam itself. We want to restore religion to its essence, our belief in God, something beautiful in our heart ' but not in the state or the law.

The result would be that religion is returned to people. Each person can have his or her own religion, and respect the rights of others to have theirs. The minimal theory of Islam says that Islam should be about living one's life, not running society or ruling the state. This does not require a politics of Islam, an economics of Islam, a social affairs of Islam ' the maximum theory of Islam, or Islamism. You don't need the state to impose religion.

The new paradigm that revolves around liberalism, democracy, pluralism, and human rights is completed by secularism. Its embodiment in a new constitution will be the work of Iranians ourselves. But to ease its birth, we want and need the support of international civil society. We are in a global era where borders are being transcended. We need global support.

But this help should not be military. Although some Iranians call American forces the 'soldiers of democracy' (and believe that Britain supports the mullahs), I believe we cannot achieve democracy by means of an invasion. We must grow it ourselves, through civil society, participation in social and political affairs ' not through military force.

At the moment the main focus of international discussions about Iran, its future and its relations with the west, is the nuclear question. This is a diversion. What matters is the nature of the country's government. Whether or not there is a nuclear programme and what danger it poses is altered by the stability and character of the governing circles. If Iran becomes a society with a democratic government operating within a constitutional settlement that is based on human rights principles, then this changes the relevance of any nuclear capabilities it may have or develop.

The demand that Iran's government is transparent about its weapons programme is much less important than whether Iran can have an open and transparent political and constitutional system that the Iranian people themselves can trust. This is where trust starts: it can't be imposed from outside. Indeed, the danger of this diversion is that it will harden the regime and even strengthen support for it, the very opposite of what should be happening.

This article forms part of an ongoing debate about Iran's democratic future on www.openDemocracy.net Don't miss trenchant critique of Sazegara's case for a referendum from Bahman Kalbasi, Bezhad Yaghmaian, Farideh Farhi and Kevah Ehsani.