Artful-

Quetzalcoatl, I'm sorry but you need to read Dawkins' words more carefully. He says on the one hand that "nature is pitifully indifferent".

It's you who needs to read more carefully. He said "pitilessly indifferent".

The full quote was:

I would simply say nature is pitilessly indifferent to human concerns and should be ignored when we try to work out our moral and ethical systems.

You said:

If his definition of "nature" does not encompass everything, then we are appealling to some quality or property that transcends nature, which is clearly dualistic and even mystical. It is mystical and mystifying because it appeals to an unexplained, unexamined "upper storey" which is exempted from the pitilessness and indifference that define nature.

There's nothing in the article to suggest that he is appealing to anything that "transcends nature".

When he says that human being are unique, in what sense does he mean this? Well he says so quite explicitly. We are unique in the sense of having more highly evolved brains. But on what grounds does this allow us to no longer be dictated to by our genes, which are our "natural" legacy. Are we thus moving into a territory where "nature red in tooth and claw" no longer prevails. What is that territory? Where is it, if it is not part of the natural realm, which is pitiless and indifferent?

I can't work out whether you're misinterpreting deliberately or not. Dawkins also said this:

One of them is language. Another is the ability to plan ahead using conscious, imagined foresight. Short-term benefit has always been the only thing that counts in evolution; long-term benefit has never counted. It has never been possible for something to evolve in spite of being bad for the immediate short-term good of the individual. For the first time ever, it's possible for at least some people to say, `Forget about the fact that you can make a short-term profit by chopping down this forest; what about the long-term benefit?' Now I think that's genuinely new and unique

Of course we are moving into territory where "nature red in tooth and claw" no longer prevails. But we do so not as a consequence of any mystical, transcendental properties, but thanks to our natural evolution.

Our brains have attained sufficient complexity to enable us to become self-aware. With that, we are able to plan on longer scales than evolution would allow for. We can take short-term disadvantage in favour of long-term benefit. But since evolution is a purely natural, unguided process, it selects for that which benefits the organism in the short term.

You said: "Where is it, if it is not part of the natural realm, which is pitiless and indifferent?"

Pitiless and indifferent TO HUMAN CONCERNS. But since we humans have the attributes I mentioned above, we are able to overrule nature and move forward through society, culture and so forth. But all this is a product of our evolved brains, and therefore a result of nature.

In any case, your assertion that Dawkins is in some sense a dualist is flawed. Quite aside from the fact that he does not mention the concept, there is nothing in the article to suggest that he has that opinion. You are simply cherry-picking parts of his statements in order to try and prop up your floundering dualism idea.