Consciousness and the Problem with Physicalism
In this text, I’ll try to explain with maximum clarity why I believe physicalism to be an insufficient explanation for phenomenological consciousness. This will include some arguments, analogies and thought experiments I’ve employed in the past, as well as an effort to understand why these discussions often end with the impression that both sides are talking about different things.
To all reading this, I ask you to try to engage with these problems as openly and honestly as possible: to make a serious effort to recognize that there can be a problem which demands careful examination. If you are unable to do this, or just don’t care enough, it makes little sense to continue reading.
Consciousness, or, more specifically, phenomenological consciousness, refers to the capacity for something to have subjective experience. Typically, this applies to informational networks which can experience their own internal states in some way. The only consciousness that we know for certain exists is our own, because we can only access our own experiences. It follows from this that it is impossible to verify that an external entity is conscious; we can only infer it from behavior, but not actually prove it. I’ll elaborate on this further.
One of the most frustrating things about any talk involving consciousness is that people often refer to entirely different things when talking about it. Even if one accepts the definition I presented above, their intuitive grasp of the concept remains different from what I truly mean. That is because most people don’t have a clear intuition of consciousness, in my experience.
Consciousness is not the same thing as self-awareness. When people say they can “prove” something is or isn’t conscious, they often have some idea related to self-awareness in mind, but self-awareness is no guarantee of subjective experience. Self-awareness can also exist in different degrees (different entities have different levels of insight), whereas the existence of consciousness is binary: either something is conscious (has subjective experience) or it isn’t. Consciousness is the existence of a “first-person perspective”, a type of space which can be filled with sensations (which is not the same thing as memory).
To illustrate, here is a thought experiment: you have two people, A and B, who are conscious. They each have their own set of memories, tastes, behaviors and personality. A mad scientist captures them both and subjects them to a series of procedures which result in person A gaining a perfect match of all the physical and mental traits of person B, and vice-versa. They didn’t swap bodies: their own, original bodies just changed in a way that made them identical to how the other person was before the experiment started, while remaining awake during the entire procedure.
In the scenario I described above, A and B essentially became one another, while retaining the original consciousness. The consciousness (perspective) that was originally with person A didn’t get magically transported to person B, just because person B obtained the memories of person A. To both of these people, there was a continuous transformation between two different states that just happened to coincide with the state of another person.
The point of this thought experiment is to show that the concept of consciousness is independent of assumptions of physicalism/dualism or any other variant: the concept remains valid regardless of these assumptions, and has a very clear meaning to those who grasp it. To further illustrate the concept, one can make a different thought experiment involving the creation of several identical brains: they still have separate consciousnesses, because consciousness is the existence of a perspective, not the set of measurable mental faculties of an individual.
Now onto physicalism, and why I believe it has a problem with consciousness.
Physicalism is the assumption that the most fundamental aspects of existence are the physical phenomena which can be mathematically described and verified, such as the fields and particles which compose the Standard Model: currently the best model we have to explain reality on the subatomic scale. “Fundamental” means that they are not “made” of anything else: they are described simply in terms of attributes such as mass, charge, spin, etc., which explain their relational characteristics and behavior. From a scientific standpoint, this is good enough, because it keeps assumptions to the minimum necessary: we don’t really need to know why the particles are exactly what they are for them to be useful in our model. In truth, there is nothing preventing these phenomena to be caused by something else more fundamental.
The problem is that the initial physicalist assumption conflates what is “useful” with what is “true”, and these are not remotely the same. Utility is not a necessary component of truth, but the measure of a good scientific model is to explain as much as possible with as few assumptions as possible. Reality, however, has no obligation to fit neatly into our most useful models, and can, in fact, include any number of phenomena which cannot be directly verified or described in simple terms. Science tells us something about the reality we can interact with, using data from the very reality we can interact with: it tells us nothing about any potential reality we cannot interact with, which doesn’t make them any less real.
So why is the physicalist position so prevalent?
The first reason is simply scientism: a tendency to believe that the scope of science is greater than it actually is, and that it is the right tool to explain everything there is to explain about existence. It is, in a sense, a contempt for philosophy: treating it as something obsolete. It is also related to the problem described above: a tendency for people to have their beliefs hinge on what is practical (a tendency we all have to some extent).
The second reason is a form of cognitive bias that conflates non-physicalism with religion or mysticism. It’s an almost knee-jerk reaction from Atheists to defend a physicalist position as a way to escape the stink associated with religious or magical thinking, which leads to a preemptive “handwaving” of things such as qualia and the Hard Problem of Consciousness, dismissing them as mere illusions (even though they are crystal-clear and self-evident concepts to myself and others). The truth, however, is that it is perfectly reasonable for both religion and physicalism to be false at the same time, and I think that they are.
Now we can discuss consciousness a bit more in-depth. I’m going to copy some sections from another text that I wrote on Consciousness and Meaning, as I believe they’re relevant here:
“Consciousness, as I understand it, is the capacity for subjective experience. If something is conscious, then there exists a perspective of what it is like to “be” this thing. Can you “be” a toothbrush? Does the toothbrush experience its own existence? Almost certainly not. I say “almost”, because it’s actually impossible to know for sure. The only consciousness I can access is my own, as I cannot directly verify the existence of any other. To verify it, I would need to experience it, but anything I can experience is a part of my own consciousness.
I can infer, through behavior and other signs, that other human beings are conscious as well, and I assume the same of many other animals. I cannot be certain of it. This is the so-called “Problem of Other Minds”. It is reasonable to assume that other people are conscious, because a false positive in this instance is preferable to a false negative, which can have disastrous consequences.
We know that consciousness is tied to the brain. However, is consciousness the brain, is it an emergent property merely caused by the inner workings of the brain, or is it an independent entity that links itself to any available object capable of processing data and checking its own internal states?”
In the next section, I discuss sensations which have an associated affect, and make a thought experiment involving a robot:
“Let’s talk about pain, because pain is probably the most familiar to a lot of people: when a part of the body is damaged, pain receptors will send a signal to the brain, which will act accordingly to avoid further pain. But how does the brain know that pain is bad? The signals sent by pain receptors are reliant on the same entities (synapses, neurotransmitters) as the signals of other nerves around the body. The pathway matters, of course. There is a part of the brain that is hardwired to interpret the signal it receives in the way it does, and you will feel pain if this area is stimulated through other means. That is straightforward enough, and we can use the same logic to program a robot to use its sensors to detect when a part is damaged, then use this signal to trigger a response that may avoid further damage.
But something is missing, isn’t it?
Will the robot that is programmed to receive a signal and interpret it in a way that allows it to avoid further damage actually experience pain? No. It will not, unless it is conscious, which it doesn’t have to be. The flow of information alone is not sufficient to explain our internal, visceral and undeniable experience of pain, and the same applies to all other experiences, or qualia (a term many people love to scoff at). That is the Explanatory Gap. Some deny that it exists at all. Every serious attempt I made at evaluating this matter has led me to the conclusion that they are wrong. Either I’m delusional, or I can see something that they can’t. I don’t think I’m delusional, and I know I’m not lying to myself either.
There is nothing that tells us why this happens the way it does, but it does. There is nothing that explains the painfulness of pain, the redness of red or the joyfulness of joy. What we can explain is the data and how the data flows, but not the experience that arises from this flow of data. Nobody knows why this flow of data is conscious of itself.”
Now, I want to get a bit more technical. A brain is an informational network, and informational networks are perfectly able to explain things related to memory and processing. When it comes to subjective experience, some people use a “black box” approach: they admit that they don’t know how a certain network generates a particular sensation such as pain, but they simply assume it does. The “how” is actually important, though, because we are looking at fundamentally different things: an informational network can be reduced to a graph or flowchart, but a sensation cannot: only its input can.
Here we can do another thought experiment involving a processor and its output devices. We know exactly how a processor works, including the fact that a processor cannot generate an image by itself: it generates the input for another device (a screen), which then converts it into an image we can see with our eyes. Does the array of bits that form an image in a screen hold the intrinsic meaning of an image to the processor itself? No, it does not. The same array of bits that form an image can be read by another device to generate a (likely unpleasant) sound or (likely unreadable) text. But the bits themselves have no meaning for the processor, and there is no reason to assume that the processor experiences these arrays of bits as having distinct meanings and generating distinct sensations.
The brain is a type of processor, and it certainly explains the input needed to generate subjective experiences, but, like the CPU, it just deals with the data itself. We have distinct qualia that cannot be reduced to a common denominator, such as pleasure/pain, color, sound and taste. Synesthesia is just different types of sensations arising from the same source; you cannot directly convert something like pain into color: you can only say that a combination of colors is unpleasant, but the colorfulness and unpleasantness remain distinct and mutually exclusive types of sensations. We have areas in the brain responsible for generating the input that is ultimately interpreted as these qualia by something (the consciousness). In other words, and this is important: informational networks are merely quantitatively different, but subjective experiences are both quantitatively and qualitatively different.
If we assume that the informational networks associated with each sensation actually hold the intrinsic meaning of each sensation, that is akin to saying that pain or pleasure is just a graph or array of bits. It is intuitively absurd. If we make a circuit that follows the same pattern associated with these areas of the brain, will it be conscious? What if we add or remove a node? At some point, you will have to postulate that a network needs to have a specific number of nodes and connections to be conscious, and that anything simpler will not be conscious, because, again, either something is conscious (has a first-person perspective), or it isn’t. Even if you say that a sensation emerges from this circuit, and that the circuit experiences its own internal states, you still can’t explain how or why. The threshold of complexity is completely arbitrary. It just makes no sense. In the end, you’re assuming physicalism “just because”, regardless of the obvious gap it generates.
And this is why I believe that consciousness is a fundamental phenomenon, distinct from the world we can physically interact with. I still don’t know why it exists and links itself to this brain, but I know it does. And there is nothing wrong with this. That doesn’t mean it’s “magical”. That doesn’t mean it’s “supernatural”. That means it is something else.