Ben Affleck on last night's Bill Maher show. (HBO)
Ben Affleck on last night's Bill Maher show. (HBO)

Film star Ben Affleck engaged in a furious debate with author Sam Harris and TV host Bill Maher, accusing his opponents of racism after Harris called Islam 'the motherload of bad ideas.'

The trio clashed on HBO's Real Time With Bill Maher when the subject of Islamophobia came up.

Harris, who was on the show promoting his book Waking Up, said: "Liberals have failed on the topic of theocracy. They'll criticize white theocracy, they'll criticize Christianity. They still get agitated over the abortion clinic bombing that happened in 1984.

"The crucial point of confusion is we have been sold this meme of Islamaphobia – where every criticism of the doctrine of Islam is conflated with bigotry towards Muslims as people. Which is intellectually ridiculous."

Affleck responds by saying, "You are saying that Islamaphobia is not a real thing? It's gross, it's racist. It's like saying 'that shifty Jew'."

Harris responds: "We have to be able to criticize bad ideas and Islam at this moment is the motherload of bad ideas."

Visibly irate, the Oscar-winning director sits back in his chair and said: "It's an ugly thing to say."

Supporting Harris' position, Maher continues the conversation: "Let's get down to who has the right answer. A billion people you say, all these people don't hold these pernicious beliefs. That's just not true Ben, that's just not true."

Affleck responds: "The people who actually believe that you should murder someone if you dishonor the Islamic faith is not with the majority of Muslims at all."

Arguing for the prevalence of illiberal ideas in Islam, Harris says: "At the center of the circle you have jihadists who wake up in the morning wanting to kill apostates, wanting to die trying, they believe in Paradise, they believe in martyrdom.

"Outside of this you have Islamists. People who are just convinced of martyrdom and Paradise and wanting to force their religion on the rest of humanity.

"But they want to work with in the system and they are not willing to blow themselves up on a bus. They want to change governments, they want to use democracy against itself.

"Those two circles are arguably 20% of the Muslim world. Based on a bunch of polls that we can talk about.

"To give you one point of contact, 78% of British Muslims said the Danish cartoonist (who was accused of depicting the prophet Mohammad in an animation) should have been prosecuted.

"But outside of that we have conservative Muslims who say that 'Isis does not represent us, that we are horrified by that'. But they hold views about human rights and about women and about homosexuals are deeply troubling.

"These are not Islamists, these are not jihadists. They also keep women and homosexuals immiserated in those cultures.

"And we have to empower the true Muslim reformers in the world to change it. This behaviour is not going to do that."

Affleck responds: "How about the more than a billion people who aren't fanatical, who don't punish women, who just want to go to school, have some sandwiches, and don't do any of the things you say all Muslims do?"

Maher: Islam acts 'like the Mafia'

Michael Steele, a political analyst for MSNBC and former chairperson of the Republican National Congress, defended Affleck saying that moderate Muslim voices do not receive as much coverage as radical ones.

Maher responds to this by saying: "One reason they [other views] don't get exposed is because they are afraid to speak out. Because it's the only religion that acts like the Mafia. That will f***ing kill if you say the wrong thing, draw the wrong picture or write the wrong book."

Seeking an explanation, Affleck then asks the panelists: "What is you answer? Is it just to condemn Islam? We've killed more Muslims than they have killed us by an awful lot."

After 10 minutes of debate, Maher moves the show on, remarking that the panel will never see eye-to-eye.

Throughout his career, Bill Maher has repeatedly been highly critical of religion. After the World Trade Center attack by terrorists, Maher called himself as a "9/11 Liberal": a liberal who views Islam as dangerous.

Maher is also a board member of Project Reason – an organisation aiming to promote scientific knowledge and debunking religious beliefs – which Sam Harris founded.