What if religion never existed?

Deep.  Except it is.  Even actively encouraged or specified marrying in the family.  Some didn't think it forbade a lot of incest at all.


divine predestination

What makes you so sure? Surely you aren't suggesting that religion has a mind of its own, or that there actually is a God behind those religions - meaning the religious precepts represent the actual moral code of an actual God? Those religions got their rules from people - this is not a chicken and egg scenario, people came first, before religion. If religion places a ban on something, it is because people wanted it banned. Even without religion as their vehicle, they would still have wanted the same things banned.

Judaism was not alone - or even first - to ban incest, by the way. Hinduism is older, and is every bit as adamant that incest should never occur. The Romans banned incest for religious reasons, too, and they would hardly have gotten that idea from the Jews, who were barely tolerated.


If you live anywhere in the West, the law isn't going to care if the incest that took place was between consenting adults and family planning was not in the picture. The authorities are naturally going to care very much indeed if minors were involved, or if the incest resulted in pregnancy.

No but religion has influence just like Marxism does. The idea of religion have/had a hold on people like no other ideas do.

True but religion is a more effective vehicle. Are you gonna go faster on a bike or in a car?

There are people who would consider homosexuality a bad thing because they believe god frowns upon it. If these 21st century people never came into contact with religion no such belief would be held.