The other half struggle to place him. Odd when you consider a CV that encompasses being Rosanna Arquette's love interest in Desperately Seeking Susan, the eldest brother in Legends of the Fall and, currently, Harry Boland in Michael Collins.
Still, the sexual division is nothing compared with the political polarisation Michael Collins has generated. Despite, or perhaps because of, the hype surrounding its opening last month, it remains No 3 in the current top UK grossers and has already taken more than pounds 5m at the box-office. Yet the debate rumbles on. Is it a dangerous and potentially inflammatory piece of faction? Or is it simply a laudable and long-overdue portrait of the man who negotiated the Irish Free State.
Dressed in the obligatory American leisurewear - sweatshirt and trainers - Aidan Quinn ponders the brouhaha the film has provoked. One suspects that he's secretly contemptuous of the response. He is certainly bemused. He shrugs and dismisses the "conservative British press". "Historically it's incredibly accurate," he asserts. "What the British Empire did in all their colonies is undeniable and no one of any intelligence can dispute it. The bravest thing about Michael Collins is how it makes the Irish culpable in their own story."
With a name like his, it's self-evident that Aidan Quinn has a vested interest in matters Irish. But, unlike many of his countrymen, he points out proudly that he is a first generation Irish American. His father, a teacher, took the well-trodden route from Dublin to Chicago in the Fifties in search of the American Dream. Subsequently, the young Aidan yo-yoed between Ireland and Chicago for most of his childhood, taking care to modify his accent so that he didn't stand out at school. His ties to Ireland remain rock solid.
"I was born in America but whenever I get off the plane I'm instantly comfortable. Because I've actually lived in Ireland, I have a very different view to the romantic one of the third or fourth Irish American generation. Secretly, we laugh at them. In Chicago they dye the river green on St Patrick's Day. In Ireland there's none of that - it's not a big deal."
In a peculiar twist of family fate, Aidan Quinn can also claim a genuine family connection to his role. He recalls how, as a child, he learnt that his grandmother played her own small part in the Easter Uprising of 1916. Working in a hotel opposite the infamous GPO building, she acted as messenger for both Michael Collins and Harry Boland while helping shelter them from the British authorities.
Quinn's own involvement in current Irish American politics is harder to pin down. "I'm involved in being an Irish American," he replies, stonewalling my question and reaching for another cigarette.
In that case, with the Dublin Summit scheduled for next week, in which camp would he place himself?
"In one that is progressing sanity and peace. I have no patience with sectarian violence." He pauses. "But if you want to know my real opinion, like a lot of people, I've been fighting very hard to be anti-violence and middle of the road.
"Now I have more sympathy for the Republican position because what has happened in the past two years is so unbelievably absurd. The IRA lay down their guns for 17 months and then new preconditions are set up. I think it took Herculean efforts by Gerry Adams to keep that side quiet. It is the empowered people who are entrenched in unyielding, cynical positions."
If the sentiments are passionate, Aidan Quinn's delivery is not. His replies are so steady, so unerringly calm, I wonder what it would take to rile him. The question amuses him. He tells me not to be fooled. "There's no question I have a short fuse," he says, relieved to be leaving the murky terrain of Irish politics. "When I was younger it was worse."
And, in a parody of a West Coast accent, he adds: "Me and my brother had a good few scraps. Now I think I've learnt to channel it in a more positive manner."
Eighteen years ago, 37-year-old Quinn was a disgruntled roofer. Now he is much in demand. In another historical role, he plays Richmond in Al Pacino's docudrama about Richard III, Looking for Richard, out in the UK next month. The film - the publicity hand-out refers to Shakespeare's "gripping drama of power lust and betrayal" - tells the story of actors preparing for the play and tries to explain the playwright's thinking. He also has more bankable appearances later in the year in Commandments (with Friends star Courtenay Cox) and The Jackals (with Donald Sutherland).
Married to actress Elizabeth Bracco, Quinn lives with their seven-year- old daughter Ada outside New York, where she attends the local school and he hangs out with the boys playing in the local basketball team.
"In this business you're always working but I try to have six months at home each year. Occasionally we go to a premiere but usually only if a friend is in it or it's a charity and we feel obligated."
He will be spending precious little time in the US next year because yet again he will be returning to Ireland for another film project - a family affair, with his elder brother lined up as cinematographer and his younger brother as writer/ director. "I'd love to go there permanently but I think I'd have to be much older before I could do that. When I was over before there was a whole fishing village on the Galway for sale and I showed it to Liam Neeson and said we should buy that. It was so cheap - we could have done it up for friends and family. I'm still looking."
Finally, what about that adoring public of his? How does it feel to be described as "sex on legs"? He throws his head back. "That whole thing makes me laugh because it's so absurd. It really has very little to do with who you are."
A sentiment rather belied by "those eyes".