You’ve probably never heard of the problem of other kidneys or spent time wondering if anyone else has kidneys. The problem of other minds is different. Even if we knew all the physical facts about the human body, we still can’t directly confirm if someone else is conscious. A brain scan can show us the brain, but it can’t give us an image of consciousness because it’s not a physical object. If we want to know if anyone else is conscious, we have to infer it from something else.
This asymmetry between consciousness and kidneys reveals a structural feature of consciousness that most theories don’t capture. Consciousness gets redefined as something we can measure, like information processing or neural activity. Theories substitute their own explanatory posits and then call that consciousness. What gets lost in this substitution is the feature that makes consciousness unique.
This article identifies what that feature is, not by stipulating a definition, but by deriving it from the problem of other minds. The aim isn’t to establish which ontology is correct, the point comes before any debate about metaphysics. It shows that any explanations that don’t preserve this feature aren’t actually explaining consciousness, they’ve just changed the subject.
The problem of other minds
To derive rather than stipulate our definition, we have to look at why the problem of other minds exists in the first place. The problem reveals something structural about consciousness. The problem is created because of the specific way we know about it. The way we know about our own consciousness is by direct acquaintance, whereas the way we know about other instances of consciousness is by inference.
From the fact that you’re conscious and know your own inner states, you observe other people’s behaviour and infer that the best explanation is they’re also conscious. For example, when you experience pain, you cry, complain, and take pain medication. When other people act the same way, the best explanation is they’re also experiencing pain.
We have the same physical structure as other humans and can communicate with each other about our inner states. The inference from our own consciousness to theirs is safe. But as we move further away from cases similar to ourselves – from humans to animals, to insects, to plants – our conclusions become less confident because the inference is based on looser correlations.
When it comes to plants and insects, the gap between our own consciousness and the observable signs is larger, and our inference becomes correspondingly less certain. AI complicates this inference even more, it has language and appears to understand, but it lacks the common biological substrate.
If consciousness were just another physical property, the problem of other minds would look like the problem of other kidneys. Even though we can’t see other kidneys directly, we can gain images of them with ultrasound and failing that, we could cut open the body and see them directly.
There’s no philosophical mystery about kidneys. But when it comes to consciousness, some kind of inference is required to know it exists in every case except our own.
The only reason there’s a problem of other minds is because of this asymmetry between our consciousness and others. If consciousness wasn’t directly given anywhere, we’d have no basis to infer it in others. Which means direct acquaintance isn’t an optional feature of consciousness, it’s the structural condition under which consciousness can be identified as a phenomenon at all.
Consciousness is self-presenting
The fact that inference is required for other minds creates an asymmetry between first-person and third-person access. This asymmetry highlights the distinctive feature of consciousness, it’s self-presenting. You don’t need a torch to see the sun, and you don’t need an intermediate device to know that you’re conscious. We don’t see ourselves taking pain medication and then infer from our behaviour that we must be in pain. We first know we’re in pain, and that causes our behaviour.
It’s important to be clear what self-presentation means. We might think it’s just a property consciousness has, something like water being transparent. But self-presentation isn’t one property among many that consciousness happens to have. It’s the mode in which consciousness is given to us at all. It’s not what consciousness is like, it’s how consciousness shows up.
This is an important distinction because a property can be abstracted away while the phenomenon remains. You can talk about water without considering its transparency and you’d still be talking about water. But you can’t abstract away from the self-presenting character of consciousness while preserving the phenomenon. Pain that isn’t self-presenting isn’t hidden pain, it’s a contradiction in terms.
Self-presentation isn’t one datum among others to be explained. It’s the condition under which there is any datum of consciousness at all. It tells us about the structure of the phenomenon we want to explain, not what that structure reveals about the fundamental nature of reality.
Why standard scientific explanation doesn’t apply
This self-presenting structure is why consciousness causes unique explanatory difficulties. Think about how explanation usually works in science. In most cases the distinction between how we know about something (epistemology) and what that thing actually is (ontology) isn’t relevant to the nature of the thing itself.
You can know about a distant planet by looking through a telescope, but the planet exists independently of the telescope. The telescope is a tool, it doesn’t define what the planet is.
Physicalist theories try to apply this same method to consciousness and retain that gap between knowing and reality itself. They argue that although you know your consciousness through first person access, consciousness is “really” just neurons firing.
But consciousness collapses the usual gap between how things appear to us and how reality actually is. Objects appear solid to us but science can explain how they are really mostly empty space. But if you’re in pain, the experience is presented to you directly, there’s no intermediate instrument. There’s no pain-object behind the unpleasant experience we can discover on a brain scan. When it comes to conscious experience, the appearance is the reality.
This means that the mode in which consciousness appears can’t be discarded as an accidental feature of access. It’s not like the telescope. A theory that explains the neurons but doesn’t account for the first person givenness hasn’t explained consciousness from a different angle. It’s failed to describe a structural feature of the phenomenon.
Any theory that ignores the self-presenting character of consciousness hasn’t approached the phenomenon at a higher level of description, it’s replaced the phenomenon with third person explanatory posits.
Preserving the phenomenon
If we want to investigate any phenomenon, our definitions need to account for it, not be imposed by the theory we use to explain it. Think about how water was explained. First the phenomenon was specified, water is the liquid found in oceans and rivers and puddles.
When science discovers an identity between that liquid and the chemical composition of H2O, the explanation succeeds because it preserves the original target. It explains why that chemistry can be identified with water and how that chemistry causes changes in water’s states, like ice and steam. The theory connects to the phenomenon we started with.
But the explanation wouldn’t succeed if instead it replaced water with H2O and then said the liquid in oceans wasn’t part of what needed explaining. It wouldn’t have explained water, it would have changed the subject while calling it by the same word.
The methodological principle is to fix the phenomenon first, and only then ask if your theory accounts for it. Any theory that redefines the target phenomenon has simply changed the subject.
This principle is especially important for consciousness because it’s vulnerable to the temptation to replace it with theoretical posits. Science operates primarily through third-person observation and measurement. Which means there’s a temptation to replace self-presentation with publicly observable correlates such as information processing or neural function.
The explanatory constraint needed for consciousness is not only that the theory needs to match the data, it also needs to preserve the mode under which the data is given. If it doesn’t preserve that, it’s not describing the same phenomenon.
When science says water is H2O, both sides of the identity belong to the same inferential and third-person domain. But consciousness isn’t originally given inferentially, it’s given directly. Which means re-describing self-presentation as neural firing changes the structure of the phenomenon itself. It moves consciousness from the non-inferential side of the ledger to the inferential side without explaining how the transition occurred.
Defending the constraint
It’s important to distinguish between givenness and intentionality. Intentionality concerns what consciousness is about, its contents. These contents include thoughts, perceptions and beliefs. Givenness refers to the more primitive fact that these contents are present at all.
Critics often say introspection is unreliable because the contents of our consciousness can be mistaken. Perception can mislead us. Beliefs can be false. But this objection confuses the content with the presentation. We can be mistaken about whether an object is a snake or a rope, but we can’t be mistaken about the fact that some kind of appearance is presented. The constraint concerns the existence of the presentation itself, not whether the contents of that presentation are accurate.
When we try to explain consciousness we aren’t asking what our own instance is like, we already know that. We’re asking about the general phenomenon, what all instances of consciousness share. We might call this consciousness-as-such. And to answer that question we necessarily have to abstract from the only known instance we have to work with – our own. We need to infer the existence of every other case of consciousness from public correlations.
But in every known case, either our own or inferred, the essential structural feature is self-presenting character. Any account that excludes it hasn’t produced a more general description of consciousness. It’s produced a different concept entirely, one that wasn’t derived from the known phenomenon.
The essential feature of self-presentation isn’t arbitrarily selected from our own case, it’s derived from the fact that inference is our only access to consciousness-as-such. And the inference isn’t a generalisation from one sample, it’s an identification of the conditions under which consciousness can be a stable referent at all.
A possible objection is that this confuses how consciousness is known with what consciousness is. But this objection assumes we have independent access to the general category of consciousness-as-such. We don’t.
Our own human consciousness is the only instance we have and can use to identify it in others. So if we leave out self-presentation, and call what’s leftover consciousness-as-such, we haven’t discovered or accessed this broader category that defines all instances. We’ve constructed it.
The objection assumes what’s in question. You have to know what consciousness is from the inside before you can decide what counts as an instance of it. Excluding self-presentation isn’t just a different perspective, it excludes the basis on which the word consciousness refers to anything at all.
This constraint that self-presenting character is the essential defining element doesn’t settle the ontology. The argument isn’t that introspection gives us access to the fundamental nature of reality, it’s that it gives us the only access we have to the structure of the phenomenon we’re trying to explain.
Self-presenting character isn’t evidence for any particular metaphysics. It’s a methodological constraint, it rules out any explanation that excludes self-presentation because that is the essential feature that specifies the target phenomenon.
Consequences for physicalist theories
What are the consequences of applying the constraint to explanations? The hard problem is often phrased that structure and function are insufficient to explain consciousness. This constraint shows why.
Structural and functional descriptions are third-person descriptions. Self-presenting character is what third-person methods can’t capture in principle. It’s not an explanatory gap in current knowledge, it’s a consequence of the structural difference between the two modes of access.
Functionalist theories describe the third-person conditions that correlate with consciousness. But if functions were enough to identify the existence of consciousness, inference wouldn’t be necessary. You’d only need to check if the functional organisation was present. If the explanation doesn’t show that self-presentation is an inherent feature of the function, it hasn’t explained consciousness.
For example, Global Workspace Theory says that consciousness arises when information is available across multiple cognitive systems. But it doesn’t tell you whether that information is directly given. Applying this constraint, it has explained various aspects of cognition, but not consciousness.
Another theory is Illusionism, it says phenomenal consciousness is an illusion produced by the brain. But an illusion is still an appearance of some kind. Illusionism challenges the accuracy of the contents of that appearance, but it doesn’t remove the fact of the appearance itself.
Even if the brain is misrepresenting things, the misrepresentation or illusion has the structural feature of being self-presenting. You still have to infer the existence of someone else’s illusion but you’re directly acquainted with your own. So the problem of other minds applies to the illusion itself, not the contents.
The minimum condition
For any theory of consciousness to succeed, it has to preserve self-presentation as an essential feature rather than eliminating or redefining it. This constraint isn’t a preference for some particular explanatory style. It’s a requirement derived from the only case in which consciousness is known directly rather than inferred. As such, it’s the only instance of the phenomenon in question that we can use to infer the existence of other minds.
This constraint doesn’t settle the hard problem or rule out any particular metaphysics, it clarifies what the hard problem is. The difficulty with explaining consciousness isn’t a gap that can be closed with more third-person data, it’s a structural feature of the phenomenon in question that’s revealed by the two modes of access.
Without self-presentation it’s no longer explaining consciousness as we know it, it’s replaced it with a theoretical substitute. If a theory leaves out self-presentation it hasn’t explained consciousness, it’s explained something else and called it consciousness.
Feature image by Rodrigo Gonzalez on Unsplash
Unity in Difference 