During this debate Jessi Fischer, a writer on sexuality, proclaimed that one of the worst porn shows she has ever watched showed two women going to scratch out each other's vaginas with their long, painted finger nails. Watching the first half of the Union debate was a similarly bad viewing experience: rather than concentrating on whether porn does a good public service, both sides seemed more interested in making catty attacks on the other side's credentials. Thankfully the real porn star argued her case against the industry effectively, bringing the debate closer to its climatic finish.

Porn is "like a game," according to Anna Span, Britain's first female porn director. According to Span, we should ignore the claims that porn provokes sex offenders or that the industry's workers are riddled with STDs, because apparently such facts and statistics are incorrect and easily manipulated. She insists that there is no link between porn and rape, or between children, porn and paedophiles. Conversely, porn provides "one of the best ways to change perceptions of sexuality and to expand women's rights". Span's real anger, however, was not directed against the "moral entrepeneurs who target the porn industry," but towards Shelley Lubben, former porn actress and now anti-porn campaigner. Span attacked Lubben's health statistics, undermined her degree and blamed her history of prostitution for her claims of cervical cancer, herpes and miscarriages. Span thrust her sharp catty claws into Lubben, presenting her as a woman who had merely joined the opposition to porn because it appeared to be more lucrative.

Span first brought the bitch into Thursday's porn debate, but the cattiness had only just begun. Fischer told us that porn is good because it "sparks public debate," but I don't think it was a debate that Fischer was after. When a young gentleman from the floor posed a point of information, she completely ignored his words and seductively flicked her hair, replying, "you and I could grab a camera right now and film whatever we want" - prompting males in the chamber to clap and laugh. This only seemed to prove the opposition's point that porn is detrimental to our society because it stops men from thinking and keeps them masturbating.

The most forceful argument of the debate came from Dr Gail Dines, lecturer and feminist activist. She is often told that "what you need, Gail Dines, is a good fuck," but here is a woman who understands that "anti-porn doesn't mean anti-sex." She gave a graphic, powerful description of the realities of porn websites like Gonzo, where "bitches have no choice but to take it all" and where women, according to Dines, become "fuck objects". She reminded us that porn is often humiliating, degrading and brutal, and to see the effects all we had to do was watch Lubben take to the floor. She was angry and inarticulate. She didn't hide behind prepared rhetoric. She dug her heels into the ground and begged: "Please, please don't believe the lie of pornography... I've been there, done that, more than any of you have." To look at her you can see that she is right: "there is nothing glamorous about porn". It leaves you broken.

The motion was carried, but this was not because of overwhelming support but because nearly a third of the chamber abstained. Perhaps they couldn't deal with the reality of porn. In the emergency debate 'This House Would Rather Be At Oxford Than St John's', white males brought the stereotypical Cambridge elitism to the chamber, with all its Chardonnay, Conservative Party members, May Balls, Boat Races and University Rankings. Maybe the motion was passed because the voters are too far removed to understand the real issues of porn, or maybe because porn has succeeded in deadening and dehumanising brains. Or maybe Lubben is right: only when anyone "has done as much gang bang as me" are they qualified to talk about porn.