Is the World Inconceivable Apart from Consciousness?

That depends. It depends on what 'world' means.

Steven Nemes quotes Dermot Moran on the former's Facebook page:

[1] In contrast to the outlook of naturalism, Husserl believed all knowledge, all science, all rationality depended on conscious acts, acts which cannot be properly understood from within the natural outlook at all. [2] Consciousness should not be viewed naturalistically as part of the world at all, since consciousness is precisely the reason why there was a world there for us in the first place. [3] For Husserl it is not that consciousness creates the world in any ontological sense—this would be a subjective idealism, itself a consequence of a certain naturalising tendency whereby consciousness is cause and the world its effect—but rather that the world is opened up, made meaningful, or disclosed through consciousness. [4] The world is inconceivable apart from consciousness. [5] Treating consciousness as part of the world, reifying consciousness, is precisely to ignore consciousness’s foundational, disclosive role. ( Dermot Moran, Introduction to Phenomenology, p. 144

This strikes me as confused. I will go through it line by line. I have added numbers in brackets for ease of reference.

Ad [1]. I basically agree. I'm an old Husserl man. But while conscious acts cannot be properly understood from within die natürliche  Einstellung, it doesn't follow that they cannot be understood "at all" from within the natural attitude or outlook. So I would strike the "at all." I will return to this issue at the end.

Ad [2].  Here the trouble begins. I grant that conscious acts cannot be properly understood in wholly materialistic or naturalistic terms. They cannot be understood merely as events in the natural world. For example, my thinking about Boston cannot be reduced to anything going in my brain or body when I am thinking about Boston. Intentionality resists naturalistic reduction. And I grant that there is a sense in which there would not be a world for us in the first place if there were no consciousness. 

But note the equivocation on 'world.' It is first used to refer to nature itself, and then used to refer to the openness or apparentness of nature, nature as it appears to us and has meaning for us.  Obviously, without consciousness, nature would not appear, but this is not to say that consciousness is the reason why there is a natural world in the first place.  To say that would be to embrace an intolerable form of idealism.

Ad [3] We are now told that this is not idealism. Very good!  But note that the world that is disclosed and made meaningful is not the world that is inconceivable without consciousness.  The equivocation on 'world' persists.  There is world in the transcendental-phenomenological sense as the 'space' within which things are disclosed and become manifest, and there is world as the things disclosed.  These are plainly different even if there is no epistemic access to the latter except via the former.

Ad [4] To be precise, the world as the 'space of disclosure' is inconceivable without consciousness. But this is not the same as the natural world, which is not inconceivable without consciousness.  If you say that it is, then you are adopting a form of idealism, which is what Husserl in the end does.

Ad [5] In the final sentence, 'world' clearly refers to the physical realm, nature. I agree that it would be a mistake to reify consciousness, to identify it with any physical thing or process. Consciousness plays a disclosive role. As OF the world -- genitivus objectivus -- consciousness is not IN the world.  But the world in this sense IS conceivable apart from consciousness. 

And so the confusion remains.  The world in the specifically pheomenological sense, the world as the 'space' within which things are disclosed -- compare Heidegger's Lichtung or clearing -- is inconceivable without consciousness. But the world as that which is disclosed, opened up, gelichtet, made manifest and meaningful, is NOT inconceivable apart from consciousness. If you maintain otherwise, then you are embracing a form of idealism.

So I'd say that Moran and plenty of others are doing the 'Continental Shuffle' as I call it: they are sliding back and forth between two senses  of 'world.'  Equivalently, they are conflating the ontic and the broadly epistemic.  I appreciate their brave attempt at undercutting the subject-object dichotomy and the idealism-realism problematic.  But the brave attempt does not succeed.  A mental act of outer perception, say, is intrinsically intentional or object-directed: by its very sense it purports to be of or about something that exists apart from any and all mental acts to which it appears.  To speak like a Continental, the purport is 'inscribed in the very essence of the act."  But there remains the question whether the intentional object really does exist independently of the act. There remains the question whether the intentional object really exists or is merely intentional.  Does it enjoy esse reale, or only esse intentionale?

I recommend to my friend Nemes that he read Roman Ingarden's critique of Husserl's idealism.  I also recommend that he read Husserl himself (in German if possible) rather than the secondary sources he has been citing, sources some of which are not only secondary, but second-rate.

To return to what I said at the outset: Conscious acts cannot be properly understood naturalistically.  But surely a full understanding of them must explain how they relate to the goings-on in the physical organisms in nature that support them.  A sartisfactory philosophy cannot ignore this. And so, to end on an autobiographical note, this was one of the motives that lead me beyond phenomenology.