Ben Affleck has won praise for accusing TV host Bill Maher and author Sam Harris for what he called “gross” and “racist” depictions of Islam during a televised debate.

Appearing on HBO talk show Real Time with Bill Maher on Friday night, Affleck reacted furiously to claims by Maher that Islam manifested as “the only religion that acts like the mafia” and which would “fucking kill you if you say the wrong thing, draw the wrong picture or write the wrong book”.

Author and philosopher Sam Harris also attracted the Argo director’s ire after suggesting: “We have been sold this meme of Islamophobia, where criticism of the religion gets conflated with bigotry towards Muslims as people. It’s intellectually ridiculous.”

Affleck, who was promoting his new film, the David Fincher thriller Gone Girl, responded: “Hold on — are you the person who officially understands the codified doctrine of Islam? It’s gross and racist. It’s like saying, ‘Oh, you shifty Jew!’ Your argument is, ‘You know, black people, they shoot each other.’”

He added: “How about more than a billion people who aren’t fanatical, who don’t punch women, who just want to go to school, have some sandwiches, pray five times a day, and don’t do any of the things you’re saying of all Muslims. It’s stereotyping.”

Maher, a fierce critic of organised religion, whose 2008 documentary Religulous examine his views on the subject, was criticised last week by the scholar Reza Aslan for appearing to suggest that female genital mutilation was an Islamic problem. “To say Muslim countries, as though Pakistan and Turkey are the same… it’s frankly, and I use this word seriously, stupid!” Aslan told CNN. “The problem is that you’re talking about a religion of one and a half billion people… and certainly it becomes very easy to just simply paint them all with a single brush by saying, ‘Well in Saudi Arabia women can’t drive,’ and saying that’s representative of Islam. That’s representative of Saudi Arabia.”