(1) In our world there are conscious experiences.

‘Our world’ designates the way things actually have been, are now, and will be. The phrase designates the real world in its entirety. Is there some sort of problem here?

(2) There is a logically possible world physically identical to ours, in which the positive facts about consciousness in our world do not hold

Premise (2) says: There is a logically possible world physically identical to ours, in which the positive facts about consciousness in our world do not hold.

I take this to say that in the logically possible world under discussion, call it Z, NONE of the positive facts about consciousness that hold in the actually world hold. If, as things actually are, I am aware of a duck swimming on a pond, in that other world, a duck is swimming on a pond, exactly as in the real world, but my counter part there is not conscious of it. In fact, my counter part (physical duplicate) in Z is a zombie. There aren’t ANY conscious beings in Z, never have been, never will be. Whether or not ducks in the real world are conscious, ducks in Z are definitely not.

We have ‘jumped’ from (discussion of) things in the real world to things in a world that is not the real world, but whose description is not incoherent or self-contradictory – a way things could have been that we cannot dismiss as impossible a priori.

In this thread there has been lots of discussion of zombies. If you have a serious reason for thinking that there is necessarily something incoherent in the description of them where do you spell this out? Where is the incoherence?

I’m sorry about my use of  ‘reveling.’ But it really does seem to me that reveling in the sound of a violin require acute consciousness of that sound, attention to, and awareness of, that sound. In a world utterly devoid of consciousness, there is, I think, so reveling in the sounds (as such) of a violin being played. Do you disagree with this wild claim?

Can you explain, exactly, what (as you see it) has gone wrong here?