deathgod said:I think a much more interesting question would be "WI Incest would be an accepted practice in our society" (which it should be).
In my eyes, it shouldn't. And for at least one reason : the bad effects of consanguinity. Genetics are a lottery, but the more consanguinity in a bloodline, the higher the risks of physical or mental health problem showing up. I know History showed several counter-examples of people who, despite being the results of high consanguinity, weren't mad or difformed (most notably several Pharaohs of Egypts) but in the late years we have heard more of bad effects of consanguinity than good ones.
The Animal World can also show the bad effects of consanguinity : there are species that are disappearing because of consanguinity. The reason is that their numbers and genetic pool have been reduced so much that they are degenerating.
Incest also pose me a problem morally and phylosophically... Humans belong to the Animal World, where Incest has no meaning. However, Humans have always been (and are in my eyes) a "special kind" in the way we developped complex societies, complex spoken languages and complex concepts that Animals didn't. Incest is one of such concepts, but how would getting rid of it would make us different from other animals?
I have nothing against Animals, but I always regarded Natural Law as something cruel since it's a world where the strong eats the weak. We live in societies where such things appear unjust. However, Animals apply Natural Law because they know no other, while we do.
Lastly, I think authorising Incest would destroy the concept of family and possibily society. If brothers and sisters, fathers and daughters, mothers and sons could marry and mate (things that happen in the Animal World), then this would lead people to be completely autonomous individuals. Thus, familial links would have absolutely no meaning, as would society.
I hope I have been clear when expressing my opinion, because I'm still finding part of my explanation a bit abstract...