Were There Ever Empirical Reasons to Bring Human Consciousness into QM?

The reason there is still disagreement as to what constitutes measurement is that it makes no experimental difference according to quantum mechanics. The way QM works under the Copenhagen interpretation is that you have to split the world into two parts, the “observer” or measurement device, and the “observed” or the particles you’re measuring.

The measurement device is assumed to behave classically. The particles in the observed system are in a superposition of states described by the wave function which keeps evolving until it interacts with the classical measurement device. The question is where to draw the line. You could consider a photon to be the observed system and an atom to be the measuring device, but you can also consider the photon-and-atom system as in a superposition of states, and take a Geiger counter to be the measurement device. So there is this von-Neumann chain, going from elementary particles to Geiger counters to human beings, and we have to decide where to cut it off.

Von Neumann proved in his famous "Bible" of QM that regardless of where you cut the chain, you would get the same experimental results. But he argued that wherever you cut the chain you have things made out of particles on each side of the cut, so there’s no principled way to place the cut in the middle. So he decided that you should place the cut between the human mind and the human body, because he believed that the mind is non-physical. Hence "consciousness causes collapse" was born. Nowadays, the most popular view is decoherence, where there is no real collapse, it's just that when you have a large number of particles in the environment interacting with the system, the wave function becomes smeared out and looks like it has collapsed. So decoherence gives us a reasonable place to cut the chain, when the number of particles involved reaches a critical number so that interference effect become negligible.

Why human consciousness? Why not just generalize all consciousness since its all only possible because of matter?

Because human consciousness is the only one that is being used to do physics, that we know of. What we know of other consciousnesses is only insofar as they mimic ours-- nothing else.

Animals use math and physics all the time, like when they are traveling distance or swimming or calculating where something will be. Even plants use math and physics to grow in the shapes they do. Humans are just the only ones who organize that information in terms of words rather than solely sub-conscious actions and feelings.

I'm wondering whether physicists in the 1930's ever had experimental reason to interpret, for example, Schrödinger's cat, as a true paradox (because of the role of a human observer). Why didn't they default to Bohr's interpretation, that an interaction with a geiger-counter, or any classically determined system, counts as an "observation."

Bohr's interpretation would seem to be the common-sense way of looking at the situation--interpretations requiring human-consciousness to be involved (which you can still frequently see in the popular press) would seem to reflect some sort of solipsism on the part of the interpreter. (In much the same way that early religious leaders insisted that the universe had to revolve around the planet where they existed.)

I personally think our consciousness comes from our constituent matters, cells, super molecules, molecules, atoms, and finally elementary particles. That is why QM is emphasized in consciousness. This statement is equivalent to saying 'matters or even elementary particles may have certain type (unlike ours) of consciousness. Our consciousness is a collective 'consciousness' (for the lack of correct word) of particles.

Do we therefore have no genuine knowledge of the intrinsic character of the physical world? So it might seem. But, according to the line of thought I am now pursuing, we do, in a very limited way, have access to content in the material world as opposed merely to abstract casual structure, since there is a corner of the physical world that we know, not merely by inference from the deliverances of our five sense, but because we are that corner. It is the bit within our skulls, which we know by introspection. In being aware, for example, of the qualia that seemed so troublesome for the materialist, we glimpse the intrinsic nature of what, concretely, realizes the formal structure that a correct physics would attribute to the matter of our brains. In awareness, we are, so to speak, getting an insider's look at our own brain activity.

This is the “structuralist” point familiar in the 1920s and 1930s (now severely underappreciated outside the philosophy of science, but reviving). It consists in the observation that the propositions of physics are equations, equations that contain numbers, terms that refer without describing, many other mathematical symbols, and nothing else; and that these equations, being what they are, can only tell us about the abstract or mathematically characterizable structure of matter or the physical world without telling us anything else about the nature of the thing that exemplifies the structure. Even in the case of spacetime, as opposed to matter or force—to the doubtful extent that these three things can be separated—it’s unclear whether we have any knowledge of its intrinsic nature beyond its abstract or mathematically representable structure.

Animals use math and physics all the time, like when they are traveling distance or swimming or calculating where something will be. Even plants use math and physics to grow in the shapes they do. Humans are just the only ones who organize that information in terms of words rather than solely sub-conscious actions and feelings.

I've come across some interesting arguments that do agree very much with this position; that is, in order to explain how the mental/consciousness/subjectivity/qualia emerge from "matter", there must be some fundamental change in our conception of "matter" or "physical", perhaps by a future physics, etc. But as per the "hard" problem, there's no hint of how one can get subjectivity out a complex network of neural connections, etc. (as presently understood). The gap between mind and matter seems immense.

When you say "animals use math", what you mean is that you recognize what they are doing based on something you do. If you had no idea what math was, you'd have no idea what those words mean. So you are using your own understanding of what math is, that's what I mean by only knowing animals by seeing them as some kind of versions of ourselves. The fact is, we have no idea what animals minds are actually doing when we claim they are doing math, but we suspect that they are doing something vaguely similar-- but only because they are already similar (our brains evolved along similar lines).

We actually have a lot of idea on what animals minds do because we can see what chemicals exist in their brain and what they get released in response to as well as see which parts of their brain activate in response to certain things.

We've actually found through chemical testing that even fish release endorphin into their blood stream when harmed and even that the same parts of the brain responsible for fear activate at the same time in a person and another animal in the same situation.

I'm saying that everything we can say about how fish think relates directly to how we think, because that's how we understand what thought (and math) are.