I'm not arguing that non-religous value systems inevitably leads to genocide.
All I'm saying, is that the western culture we have inherited, has proven to be pretty good at providing a good life for most people.
As we discover that the foundation of the religous belief system is wrong, we need be careful about how we dispense with the rules that have been justified in religous dogma up until now.
I think it can go wrong in two ways:
1. The far right atheists can argue that without Jesus, there is no objective reason for universal empathy, which we can use to justify extreme selfishness, eugenics, racism, etc.
2. Left wingers, on the other hand, can argue that ONLY empathy and happiness matters when we dispense with the supernatural soul. Because the religous reasons for free will are wrong, we should not treat individuals as moral agents, but instead treat all unwanted behaviour or unwanted outcomes as health problems or something caused by unfair treatment by society.
In small doses, I don't see either view as a big problem. But there have been cases where they have been taken to the extreme, and that went blody on both sides.
Scientifically, I think both views are simplifications to the point of being just wrong. In order to function as a society and as individuals, we need a balance between individual responsibility and empathy where it is due.
I think it is possible to reach this conclusion through science and philosophy, but that this is extremely difficult, and even more difficult to communicate to the electorate.
Which is why I argue that we should not change our moral rules too quickly, even if the traditional justification for them fall away.
Btw, it may very well be that we more or less agree on this. The discussion started further up, in response to the claim that moral behaviour (not killing) was a consequence of "being an empathic person", and nothing else.