"Little by little," he admitted, the group has been able to radicalize the thinking of young Muslims in Europe.
It is a "great error," he said, "not only of Muslims but of the world [as a whole] to accept this."
Many French Muslims, he said, "forget that they are French people. And they forget that as French people they must also [behave like] French people like the others, you know?"
It is "very important [for] French Muslim people to express their French nationality, their French taste, their French values, their French [rejection] of what is the danger for them, France, and for our religion also."
"Where are the massive marches," Amanpour asked, "by the Muslim community around the world? Just get out there and tell these Muslims, these radicals, these extremists, the people you're talking about, 'No!'"
"It is the true question," he said in English.
"But each time I talk here in the Grand Mosque of Paris they say to me, 'Sir you do not represent the Muslims, the young who think differently.' And I say yes, because I don't think like them. The people who think like me are discreet, people don't listen to us, and apart from you," he told Amanpour, "the media don't pay us any attention."
The ISIS attack that left 129 people dead in Paris last Friday has given renewed urgency to the debate over how — and whether — to beat back the ISIS stronghold in Syria and Iraq, and more broadly how to bring to an end Syria's 4½-year civil war.