Were his friend to say, "with regard to procreation, homosexuality is not a natural form of sexual intercourse" I would agree with him.
But the sweeping statement he made is too general. With debate you must be very specific with your arguments if you want them to stand scrutiny and to be considered objective by your audience or you will be labelled as discriminatory.
To follow on with 1010011010 (did you make that nick just to make my life hard?
) you could also argue that cannibalism was natural too. As is killing to control resources. Logical yes, but taking it too far.
I think better would be: Do homosexual acts occur naturally with other species? Yes. But we're so far advanced from these that a comparison is silly. Let's leave that argument.
Daoust:
Like it or not, humans were made to reproduce and "multiply". This has nothing to do with 'homosexuality is bad, but rather, is it non-productive. Before it became commonly understood that the primary purpose for sex was enjoyment only, it was intended for procreation. That's why we have sex. Procreation is necessary for survival. The fact that the act of procreation is enjoyable is a pleasant by-product, not it's primary function.
True that currently, hetero sex is the primaryy way to reproduce, but it's only for now.
There's nothing to stop gay women from being fertilised artificially by gay mens' sperm.
If the genetics game carries on, orthodox reproduction will soon be considered a foolish form of genetic roullette compared to a more secure and 'PRODUCTIVE' practice of selective genetic code breeding. The argument for homosexuality being unnatural will fall by the wayside as reproduction (the yardstick by which homosexual activity's 'natural'ness is measured) will take a more unnatural form itself.
I don't think art and procreation can be compared. Your analogy is poor.
With or without art we would survive. With only homosexuals mankind is doomed.
Art, broken down into it's more primitive sense is camouflage.
We would mimic natural surroundings to provide refuge and safety by blending into the environment. When those reasons are no longer there we use art to protray the outside environment in diferent ways and to (inversely) show the differences in sometimes stark, bold manners.
I think Art is quite a good comparison. we've moved from the need to use it to ensure our race's safe future to provide pleasure by aesthetic and emotive appeal.
Sex is continually moving from a means of ensuring the continuation of the specie to a purely pleasurable activity. As I said, soon we will no longer consider sex as a good, productive means of procreation.