Luckily with consciousness, we have a broad idea of how it emerges: The processing of information (a physically measurable property) by certain structures with many feedback loops (particularly brains) causes the emergence of consciousness; and in particular saying that it's emergent tells us that consciousness relates to the structure AND dynamics of the brain, and not to some intangible glob of soul attached to it.
So saying "emergence" plus the one sentence above actually gets us really far out of the land of mysticism.
This is a statement of materialism, not evidence or an argument that it is true.
The evidence for consciousness being a material phenomenon -- the only evidence, as far as I can see -- is the remarkable correspondence observed between physical brain phenomena and mental phenomena. But we have no knowledge of how matter produces consciousness. The hard example against which materialist woo (not all woo is mystical woo) generally fails is, "does this purported explanation predict the absence of consciousness in the cerebellum and motor control?"
ETA:...
So I just wound up in a debate with someone over on Reddit about the value of conventional academic philosophy. He linked me to a book review, in which both the review and the book are absolutely godawful. That is, the author (and the reviewer following him) start with ontological monism (the universe only contains a single kind of Stuff: mass-energy), adds in the experience of consciousness, reasons deftly that emergence is a load of crap... and then arrives to the conclusion of panpsychism.
WAIT HOLD ON, DON'T FLAME YET!
Of course panpsychism is bunk. I would be embarrassed to be caught upholding it, given the evidence I currently have, but what I want to talk about is the logic being followed.
1) The universe is a unified, consistent whole. Good!
2) The universe contains the experience/existence of consciousness. Easily observable.
3) If consciousness exists, something in the universe must cause or give rise to consciousness. Good reasoning!
4) "Emergence" is a non-explanation, so that can't be it. Good!
5) Therefore, whatever stuff the unified universe is made of must be giving rise to consciousness in a nonemergent way.
6) Therefore, the stuff must be innately "mindy".
What went wrong in steps (5) and (6)? The man was actually reasoning more-or-less correctly! Given the universe he lived in, and the impossibility of emergence, he reallocated his probability mass to the remaining answer. When he had eliminated the impossible, whatever remained, however low its prior, must be true.
The problem was, he eliminated the impossible, but left open a huge vast space of possible hypotheses that he didn't know about (but which we do): the most common of these is the computational theory of mind and consciousness, which says that we are made of cognitive algorithms. A Solomonoff Inducer can just go on to the next length of bit-strings describing Turing machines, but we can't.
Now, I can spot the flaw in the reasoning here. What frightens me is: what if I'm presented with some similar argument, and I can't spot the flaw? What if, instead, I just neatly and stupidly reallocate my belief to what seems to me to be the only available alternative, while failing to go out and look for alternatives I don't already know about? Notably, it seems like expected evidence is conserved, but expecting to locate new hypotheses means I should be reducing my certainty about all currently-available hypotheses now to have some for dividing between the new possibilities.
If you can notice when you're confused, how do you notice when you're ignorant?