"Can't we all just use our intelligence to come up with right and wrong?"

I would say that the answer to that would be "Yes. Of course." but my question deals with atheists use their intelligence to decide that.

Dawkins, seems to me to be very Naive about the issue when he often argues that there is no logical path from atheism to committing atrocities. (I know that is a paraphrase, but it is close enough and brief enough to serve this discussion.)

The very basis of what one considers to be an atrocity seems too wrapped up in one's knowledge to allow one to independently what is right or wrong.

I don't endorse any of the practices to be described. I am saying there is no "LOGICAL" reason not to engage in them.

1. One could eat the meat, properly screened for pathogens, of humans not slaughtered for that purpose.

2. One could have non-child bearing sex with close relatives.

3. As a society people with genetic flaws and low IQs could be sterilized or terminated.

4. One could use the meat generated in 3. to feed people in 1.
Or as spare parts for transplants,

No Mr. Dawkins would seem not to be the best spokesperson for Atheism because of his stunted imagination. That is an odd thought for me because I thought that most scientists would have at least a basic knowledge of speculative fiction.

There is no biological reason not to do any of the above. There is good historical evidence that people can come to think these things. So why do these ideas seem so repulsive?

In this thread Foolestroupe and Shaw, like Dawkins seem to be defining their own beliefs in terms of their differences from and criticisms of popular religion rather than from any morality or set of beliefs separate from religion. They are actually "anti-theists" rather than atheists. I will say to them as I would say to the Republicans and Tea Party about politics. It is easy to cherry pick criticisms and rage for something better. The true test of an Atheist might be to come up with something that IS better and showing how and why it is better.