It was a deeply symbolic gesture, whose significance was perhaps lost on President Mohammad Khatami's French hosts, and on his own compatriots.
The Iranian leader asked to visit the Pantheon, the French basilica completed in the revolutionary year of 1789 and later transformed into a godless temple to the great men and women of France.
There is a kind of reverse symmetry between the two revolutions: the French, which deposed a king to replace him with secularism; the Iranian, which replaced the Shah with theocracy.
Yet yesterday, Mr Khatami made the link between the two civilisations.
French police closed off a square kilometre of the Latin Quarter and deployed an army of cops. Mr Khatami arrived in a swarm of motorcycles and police cars.
En route, a protester managed to throw a yellow paint bomb at the Iranian ambassador's car. As nearby church bells chimed 11 o'clock, Mr Khatami ascended the stairs, beneath the frieze of Liberty awarding laurel wreaths to great Frenchmen.
Inside, he sought the crypt of Jean-Jacques Rousseau, father of the Enlightenment. In the late 1970s, as rector of the Iranian mosque in Hamburg, Mr Khatami learned German so he could study Kant and Hegel. In a book entitled From the World of Cities to the City of the World, he argued that if Islam is to regain its past glory it must adopt Western-style freedom of thought.
After laying sprays of red and white carnations before the tombs of Rousseau, Emile Zola, Victor Hugo, Marie and Pierre Curie, Mr Khatami climbed to the dome of the Pantheon. He then set in motion Foucault's pendulum, the scientific instrument which in the middle of the last century proved that the earth rotates.
"Today, more than ever, we need reason, logic, thought and reflection," he said in a seven-page speech to the small crowd of French and Iranian officials around him.
French onlookers trapped by the police barricades outside seemed unaware that millions of Iranian women and young people have invested great hope in Mr Khatami's struggle to reform Islam. "I'm not interested in any of those countries who mistreat women," a bystander said to me. But Iranian women like Mr Khatami, I said. "Those fundamentalists are all the same," she scoffed.
And that is Mr Khatami's challenge: to persuade the West that he does not want the hangings and stonings, the spying charges and assassinations, that these abuses are beyond his control, but that he may one day have the power to change them.
As the French writer, Jacques Attali, said yesterday, the Iranian calendar is now in its 14th century. Europe of the 14th century was only beginning to emerge from the dark ages into the Renaissance. There were men who wanted to keep it medieval, but the Renaissance triumphed.
In the cold nave of the Pantheon, Mr Khatami delivered a humanist prayer: "Instead of being blindly fanatical partisans of a certain civilisation, we must turn towards man, think of the role played by man, of the common legacy of societies in building human civilisation."
Each individual is responsible before mankind, he said. In an allusion to the shortcomings of his own country, he warned that when a society reaches the limits of the civilisation that engendered it, "this society will turn towards another thought and another civilisation".
Outside on the cold square, hundreds of security men, Iranian and French, uniformed and plainclothes, had been waiting for an hour.
A young woman wearing blue jeans and a leather jacket had somehow slipped through the barricades. When a tall cleric wearing a black turban and a flowing brown robe descended the Pantheon steps, she began shouting, "Death to Khatami, Death to Khatami".
Her cry was muffled as five riot policemen gripped her writhing arms and legs to carry her off down a side street. The young woman was mistaken - the first robed man was not President Khatami but another Iranian, perhaps a decoy.
It's true that from a distance, they all look the same.
AFP reports:
President Khatami agreed to address the UNESCO general conference today after security concerns had been resolved, an Iranian diplomat said yesterday.
Meanwhile, his visit to France drew sharp criticism from conservative and hardline newspapers in Tehran amid anger at the high-profile protests in Paris by the opposition in exile. But reformist newspapers accused their conservative rivals of damaging his efforts to secure sorely needed foreign investment with their sniping.