I got the Luas from Tallaght to Dublin city centre on Sunday evening. It was only 5pm but the hour had gone back so it was beginning to get dark. I got into the front carriage, which was lightly occupied. Near where I sat, on the opposite side, there were two young girls, maybe 14 or 15 years old. Just before the tram pulled out, a gang of seven lads got into the carriage. They were roughly the same ages as the girls, between 14 and 16. They were country boys – their accents suggested they were from the midlands. They were neatly dressed, well groomed, spruced up for a night out.

As the tram pulled out, the lads spotted the two girls and moved in on them. They literally invaded their space. Two of them sat on the available seats beside them, the rest stood over them. It was all chat – how are ye? Where are ye going? But it was intimidating. The girls got up and stood right at the end of the carriage, next to the driver’s door. The lads followed them and stood around them in a pack. They started to urge the kid who looked like he was the youngest of their number to kiss one of the girls.

I was about the stand up and shout at the boys and risk whatever would come next, when the tram pulled in to the next station. The girls got off on to the platform. I don’t know whether they waited for the next Luas or just walked down and got into a different carriage. The lads made no effort to follow them. They sat down on the seats, sprawling, occupying territory. They spent the rest of the journey playing with their phones and occasionally thumping each other. To them, nothing had happened. Related Fintan O'Toole: Ireland's young and working classes are in the Covid-19 firing line

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Scent of rape I don’t think these were particularly bad lads. Individually, they looked sweet and awkward, with that male adolescent way of not quite knowing what to do with their limbs, how to hold themselves, how to occupy space. I don’t think they gave any thought to the reality that when the seven of them surrounded those girls, it looked like a pack cornering its prey, that the threat in the air was the threat of bodily domination, the scent of rape. They were just high on being out in the city, on being together in a gang, on being able to invade a public space and assert their dominance over everyone in it – and all the better that this act of assertion carried a sexual charge.

The right has succeeded in redefining good manners as ‘political correctness’; progressives need to reclaim good manners as the necessary rules of decent conduct This wasn’t Hollywood, or a theatre, or the fashion industry, or the houses of parliament or the media world. It was ordinary, mundane. No crime was committed. If the girls complained to the police, they would be hard put to say what exactly had been done to them. They had not been touched. The verbal intimidation had not yet risen to the level of explicit threat. They had escaped before the bullying had escalated into direct physical abuse. But they had been abused nonetheless. If they did not already know it, they now know that they are vulnerable to sexual menace, even in public places. And they will know it for the rest of their lives.

We are at a very important moment in the history of behaviour, and specifically in the history of male behaviour towards women. Women have begun to find a public voice for deep private knowledge. There is a great calling-out going on and many famous and admired men will be named – as they should and must be. But as I watched this horrible little drama on Sunday evening, I couldn’t help wondering whether anything will really change if we are still raising our boys like this. Those lads have most likely already forgotten what they did – and those who forget are condemned to repeat. They had a little moment of exhilarating sexual power. If they ever find themselves with power over girls or women later in life will some of them not be drawn back to that forgotten moment, to that dark thrill?

Restraint We have to teach boys manners. There is no golden age in the past when men did not harass and belittle and intimidate women. But there was, I think, a greater restraint on this behaviour: the restraint of good manners. Boys were taught rules of conduct, especially of conduct towards girls: don’t make hurtful remarks, don’t sit or stand too close for the other person’s comfort, don’t sprawl, don’t touch without permission. The idea of good manners has become deeply unfashionable – “mannered” is now one of the most damning terms of critical abuse. But manners are really just social software, the codes that make dignified interaction possible. The right has succeeded in redefining good manners as “political correctness”; progressives need to reclaim good manners as the necessary rules of decent conduct.