The great mathematics of the Greeks they learned from brahmins in India, for one thing. For another, even the normal Greeks and Romans were disgusted at the pederasty and sodomy of the perverts, and had laws to protect boys (and young girls) from deviants. They had to send boys to schools with guards to keep them safe.
If someone wants to support homosexual behavior by citing other "cultures", how about New Guinea? If they haven't changed their ways, they have young boys living in the men's longhouse being sodomized while the women do all - and I mean ALL - the work of food growing, while the men sit around - well, doing what I just said, hunting pigs occasionally, and I think they smoke stuff or ferment spit and drink it. Also, they have the charming custom of cutting off a woman's finger every time a relative dies, so most old women (should they live that long) have very few fingers, while they hoe the sweet potatoes.
They also never, ever bathe - not even once in their whole lives.
Of course, times may have changed with the advance of civilization. I've heard many of them are now alcoholics and drug addicts.
I guess their mode of life is just as good as any, right?
I just hope Jesup and the other perversion advocates learn the truth..;-)