Utter confusion about consciousness

I’m starting to get a sense of why people like David Chalmers and Daniel Dennett call consciousness the most mysterious thing known to humans. I’m currently just really confused, and think that pretty much every position available with respect to consciousness is deeply unsatisfactory. In this post, I’ll just walk through my recent thinking.

Against physicalism

In a previous post, I imagined a scientist from the future who told you they had a perfected theory of consciousness, and asked how we could ask for evidence confirming this. This theory of consciousness could presumably be thought of as a complete mapping from physical states to conscious states – a set of psychophysical laws. Questions about the nature of consciousness are then questions about the nature of these laws. Are they ultimately the same kind of laws as chemical laws (derivable in principle from the underlying physics)? Or are they logically distinct laws that must be separately listed on the catalogue of the fundamental facts about the universe?

I take physicalism to be the stance that answers ‘yes’ to the first question and ‘no’ to the second. Dualism and epiphenomenalism answer ‘no’ to the first and ‘yes’ to the second, and are distinguished by the character of the causal relationships between the physical and the conscious entailed by the psychophysical laws.

So, is physicalism right? Imagining that we had a perfect mapping from physical states to conscious states, would this mapping be in principle derivable from the Schrodinger equation? I think the answer to this has to be no; whatever the psychophysical laws are, they are not going to be in principle derivable from physics.

To see why, let’s examine what it looks like when we derive macroscopic laws from microscopic laws. Luckily, we have a few case studies of successful reduction. For instance, you can start with just the Schrodinger equation and derive the structure of the periodic table. In other words, the structure and functioning of atoms and molecules naturally pops out when you solve the equation for systems of many particles.

You can extrapolate this further to larger scale systems. When we solve the Schrodinger equation for large systems of biomolecules, we get things like enzymes and cell membranes and RNA, and all of the structure and functioning corresponding to our laws of biology. And extending this further, we should expect that all of our behavior and talk about consciousness will be ultimately fully accounted for in terms of purely physical facts about the structure of our brain.

The problem is that consciousness is something more than just the words we say when talking about consciousness. While it’s correlated in very particular ways with our behavior (the structure and functioning of our bodies), it is by its very nature logically distinct from these. You can tell me all about the structure and functioning of a physical system, but the question of whether or not it is conscious is a further fact that is not logically entailed. The phrase LOGICALLY entailed is very important here – it may be that as a matter of fact, it is a contingent truth of our universe that conscious facts always correspond to specific physical facts. But this is certainly not a relationship of logical entailment, in the sense that the periodic table is logically entailed by quantum mechanics.

In summary, it looks like we have a problem on our hands if we want to try to derive facts about consciousness from facts about fundamental physics. Namely, the types of things we can derive from something like the Schrodinger equation are facts about complex macroscopic structure and functioning. This is all well and good for deriving chemistry or solid-state physics from quantum mechanics, as these fields are just collections of facts about structure and functioning. But consciousness is an intrinsic property that is logically distinct from properties like macroscopic structure and functioning. You simply cannot expect to start with the Schrodinger equation and naturally arrive at statements like “X is experiencing red” or “Y is feeling sad”, since these are not purely behavioral statements.

Here’s a concise rephrasing of the argument I’ve made, in terms of a trilemma. Out of the following three postulates, you cannot consistently accept all three:

1. There are facts about consciousness.
2. Facts about consciousness are not logically entailed by the Schrodinger equation (substitute in whatever the fundamental laws of physics end up being).
3. Facts about consciousness are fundamentally facts about physics.

Denying (1) makes you an eliminativist. Presumably this is out of the question; consciousness is the only thing in the universe that we can know with certainty exists, as it is the only thing that we have direct first-person access to. Indeed, all the rest of our knowledge comes to us by means of our conscious experience, making it in some sense the root of all of our knowledge. The only charitable interpretations I have of eliminativism involve semantic arguments subtly redefining what we mean by “consciousness” away from “that thing which we all know exists from first-hand experience” to something whose existence can actually be cast doubt on.

Denying (2) seems really implausible to me for the considerations given above.

So denying (3) looks like our only way out.

Okay, so let’s suppose physicalism is wrong. This is already super important. If we accept this argument, then we have a worldview in which consciousness is of fundamental importance to the nature of reality. The list of fundamental facts about the universe will be (1) the laws of physics and (2) the laws of consciousness. This is really surprising for anybody like me that professes a secular worldview that places human beings far from the center of importance in the universe.

But “what about naturalism?” is not the only objection to this position. There’s a much more powerful argument.

Against non-physicalism

Suppose we now think that the fundamental facts about the universe fall into two categories: P (the fundamental laws of physics, plus the initial conditions of the universe) and Q (the facts about consciousness). We’ve already denied that P = Q or that there is a logical entailment relationship from P to Q.

Now we can ask about the causal nature of the psychophysical laws. Does P cause Q? Does Q cause P? Does the causation go both ways?

First, conditional on the falsity of physicalism, we can quickly rule out theories that claim that Q causes P (i.e. dualist theories). This is the old Cartesian picture that is unsatisfactory exactly because of the strength of the physical laws we’ve discovered. In short, physics appears to be causally complete. If you fix the structure and functioning on the microscopic level, then you fix the structure and functioning on the macroscopic level. In the language of philosophy, macroscopic physical facts supervene upon microscopic physical facts.

But now we have a problem. If all of our behavior and functioning is fully causally accounted for by physical facts, then what is there for Q (consciousness) to play a causal role in? Precisely nothing!

We can phrase this in the following trilemma (again, all three of these cannot be simultaneously true):

1. Physicalism is false.
2. Physics is causally closed.
3. Consciousness has a causal influence on the physical world.

Okay, so now we have ruled out any theories in which Q causes P. But now we reach a new and even more damning conclusion. Namely, if facts about consciousness have literally no causal influence on any aspect of the physical world, then they have no causal influence, in particular, on your thoughts and beliefs about your consciousness.

Stop to consider for a moment the implications of this. We take for granted that we are able to form accurate beliefs about our own conscious experiences. When we are experiencing red, we are able to reliably produce accurate beliefs of the form “I am experiencing red.” But if the causal relationship goes from P to Q, then this becomes extremely hard to account for.

What would we expect to happen if our self-reports of our consciousness fell out of line with our actual consciousness? Suppose that you suddenly noticed yourself verbalizing “I’m really having a great time!” when you actually felt like you were in deep pain and discomfort. Presumably the immediate response you would have would be confusion, dismay, and horror. But wait! All of these experiences must be encoded in your brain state! In other words, to experience horror at the misalignment of your reports about your consciousness and your actual consciousness, it would have to be the case that your physical brain state would change in a particular way. And a necessary component of the explanation for this change would be the actual state of your consciousness!

This really gets to the heart of the weirdness of epiphenomenalism (the view that P causes Q, but Q doesn’t causally influence P). If you’re an epiphenomenalist, then all of your beliefs and speculations about consciousness are formed exactly as they would be if your conscious state were totally different. The exact same physical state of you thinking “Hey, this coffee cake tastes delicious!” would arise even if the coffee cake actually tasted like absolute shit.

To be sure, you would still “know” on the inside, in the realm of your direct first-person experience that there was a horrible mismatch occurring between your beliefs about consciousness and your actual conscious experience. But you couldn’t know about it in any way that could be traced to any brain state of yours. So you couldn’t form beliefs about it, feel shocked or horrified about it, have any emotional reactions to it, etc. And if every part of your consciousness is traceable back to your brain state, then your conscious state must be in some sense “blind” to the difference between your conscious state and your beliefs about your conscious state.

This is completely absurd. On the epiphenomenalist view, any correlation between the beliefs you form about consciousness and the actual facts about your conscious state couldn’t possibly be explained by the actual facts about your consciousness. So they must be purely coincidental.

In other words, the following two statements cannot be simultaneously accepted:

• Consciousness does not causally influence our behavior.
• Our beliefs about our conscious states are more accurate than random guessing.

So where does that leave us?

It leaves us in a very uncomfortable place. First of all, we should deny physicalism. But the denial of physicalism leaves us with two choices: either Q causes P or it does not.

We should deny the first, because otherwise we are accepting the causal incompleteness of physics.

And we should deny the second, because it leads us to conclude that essentially all of our beliefs about our conscious experiences are almost certainly wrong, undermining all of our reasoning that led us here in the first place.

So here’s a summary of this entire post so far. It appears that the following four statements cannot all be simultaneously true. You must pick at least one to reject.

1. There are facts about consciousness.
2. Facts about consciousness are not logically entailed by the Schrodinger equation (substitute in whatever the fundamental laws of physics end up being).
3. Physics is causally closed.
4. Our beliefs about our conscious states are more accurate than random guessing.

Eliminativists deny (1).

Physicalists deny (2).

Dualists deny (3).

And epiphenomenalists must deny (4).

I find that the easiest to deny of these four is (2). This makes me a physicalist, but not because I think that physicalism is such a great philosophical position that everybody should hold. I’m a physicalist because it seems like the least horrible of all the horrible positions available to me.

Counters and counters to those counters

A response that I would have once given when confronted by these issues would be along the lines of: “Look, clearly consciousness is just a super confusing topic. Most likely, we’re just thinking wrong about the whole issue and shouldn’t be taking the notion of consciousness so seriously.”

Part of this is right. Namely, consciousness is a super confusing topic. But it’s important to clearly delineate between which parts of consciousness are confusing and which parts are not. I’m super confused about how to make sense of the existence of consciousness, how to fit consciousness into my model of reality, and how to formalize my intuitions about the nature of consciousness. But I’m definitively not confused about the existence of consciousness itself. Clearly consciousness, in the sense of direct first-person experience, exists, and is a property that I have. The confusion arises when we try to interpret this phenomenon.

In addition, “X is super confusing” might be a true statement and a useful acknowledgment, but it doesn’t necessarily push us in one direction over another when considering alternative viewpoints on X. So “X is super confusing” isn’t evidence for “We should be eliminativists about X” over “We should be realists about X.” All it does is suggest that something about our model of reality needs fixing, without pointing to which particular component it is that needs fixing.

One more type of argument that I’ve heard (and maybe made in the past, to my shame) is a “scientific optimism” style of argument. It goes:

Look, science is always confronted with seemingly unsolvable mysteries.  Brilliant scientists in each generation throw their hands up in bewilderment and proclaim the eternal unsolvability of the deep mystery of their time. But then a few generations later, scientists end up finding a solution, and putting to shame all those past scientists that doubted the power of their art.

Consciousness is just this generation’s “great mystery.” Those that proclaim that science can never explain the conscious in terms of the physical are wrong, just as Lord Kelvin was wrong when he affirmed that the behavior of living organisms cannot be explained in terms of purely physical forces, and required a mysterious extra element (the ‘vital principle’ as he termed it).

I think that as a general heuristic, “Science is super powerful and we should be cautious before proclaiming the existence of specific limits on the potential of scientific inquiry” is pretty damn good.

But at the same time, I think that there are genuinely good reasons, reasons that science skeptics in the past didn’t have, for affirming the uniqueness of consciousness in this regard.

Lord Kelvin was claiming that there were physical behaviors that could not be explained by appeal to purely physical forces. This is a very different claim from the claim that there are phenomenon that are not purely logically reducible to structural properties of matter, that cannot be explained by purely physical forces. This, it seems to me, is extremely significant, and gets straight to the crux of the central mystery of consciousness.