RE: "But we don't need to know what the idea of consciousness is. We just need to know what consciousness is"

There is no material difference here.  By the 'idea' or 'notion' of consciousness, I mean consciousness (ie what it means).

And we would need to know it in its entirety.  If we didn't, how would we even know what was 'part' of it?   What (we thought) we knew as 'part', may, for all we knew, be an infinitesimally small and insignificant part, or maybe not even a part at all.  If one had never seen a cat, could one say that some limb one found lying around was part of a cat?

The point about 'ostending' (pointing to?) seems to me, as I said in my reply to Stevan, a red herring.  How does one point to something if one doesn't know what it is?  And to say it is 'feeling like something' raises all the problems about the notion of 'feeling' in this context. In addition, consciousness cannot surely 'feel like' anything - except itself (which other experience, precisely, could we say it 'feels like'?) And saying it feels like itself of course gets us nowhere.

It seems to me that unless one is exacting about these matters, the whole discussion just drifts off into endless confusion. Which is perhaps why there is so very little sign of any consensus in analytic philosophy about what consciousness is. Moreover, analytic philosophy, I would have thought, has a special duty to be precise and exacting, since these qualities are a large part of what it hangs its reputation on.

DA