OWK: Huh? How the hell did you get THAT from what I said?
Obviously you don't think it's a matter of inflicting harm, as that would justify the use of force to prevent it from occurring. (Your words: As such, I would submit that every act of persuasion short of initiated force should be undertaken to prevent such adults from engaging in sexual activity. )
So if it's not harm, it must be undesirable for some other reason. Specifically, if the possibility of genetically-deformed offspring is reason enough to strongly dissuade incestual relations, it means that genetically-deformed offspring are obviously less valuable than children with normal genes.
I'm not so sure it's all that "obvious" to me.
As I said in my first post... It's a tough call.
A good case could be made for either position.