And the Bulgarian Cathars gave us the word "buggery", which was a slur even back then. But the thing that keeps me from dismissing this all as wishful thinking on the part of queer-friendly sociology professors is that all those old prohibitions that I've been able to find refer to same-sex intercourse, the act (and usually only male-male intercourse at that), rather than homosexuality, the state. That doesn't exactly prove that sexual identity as such is a modern invention -- frank discussions of sexuality are rather thin on the ground in European culture between the Romans and the early modern period -- but it does seem to point in that direction: if a concept of sexual identity existed, I'd expect homosexual identities to be condemned if homosexual acts were.