how do u think about Incest?

1 ：smokewater：2014/09/26(金) 16:31:29.26 ID:C3NWOclC.net

sry 4 my writing on English,though i can tell Japanese, i couldnt describe my question on Japanese.
Okay,at first ,incest is considered not being tallied with moral principles.Second,we all know that the child who incest have more chance to have Genetic Diseases.
but we all know that moral principles is coming from the behavior that would benefit the most people.In ancient,people cant bear incest cuz they would have children with Genetic Diseases.So they forbid incest to benefit the most people.
But now we have better science,parents can have test about Genetic Diseases and prevent the harm.At least,if the child have Genetic Diseasesm,the society can afford that, so how can we oppose the incest?
yes,we can say incest not accord to moral principles，but why incest not allowed to moral principles?That's the key question.
i dont have any sisters, and i dont support or oppose insest in personal,i just wonder what the reason the society oppose incest?

2 ：smokewater：2014/09/26(金) 16:33:39.00 ID:C3NWOclC.net

What's more , as we can say the society not allowed incest.We should konw Christian in 10-14 century would like to burn the pagan，Christian even not allowed divorce.But now ,we would think those Christian all as fools ,but
Christian think what they did was correctly cuz it allowed to their Genetic Diseases.And now ,we have new science and productive forces，we changed our attitude to pagan and divorce,so why the attitude to incest not changed?
The answer maybe Interesting.I would like to see that from a Japanese,cuz culture is different all the world.
答えは日本語でもいいです、簡単の話はわかる、複雑のはグーグルで翻訳ができます