The boundaries of consciousness: Are we asking the wrong question?

On time, individual identity and the possibility of a shared subjectivity

A question left unanswered

In an earlier essay, I considered whether consciousness might be better understood as a relational phenomenon, rather than something generated exclusively by biological brains (Morrill, 2026).

My argument was that particular physical organisations, possessing the appropriate temporal, informational and self-maintaining properties, might participate in conditions necessary for subjective experience. Biological organisms provide our only secure examples, but it would be premature to assume that biology exhausts the possibilities.

I also suggested that increasingly sophisticated artificial systems might eventually help us understand aspects of consciousness that our own evolutionary history has left us poorly equipped to investigate.

I remain comfortable with the speculative nature of that position. What has begun to trouble me, however, is an assumption I left largely untouched.

If consciousness is a phenomenon that different physical organisations might instantiate, why should we assume that each manifestation belongs to a fundamentally separate conscious subject?

The distinction is important.

Two organisms might possess consciousness because they share certain organisational properties. That would not necessarily make them the same conscious individual. But neither does it establish that their subjectivity must be fundamentally distinct.

We tend to treat the individuality of consciousness as self-evident. I experience the world as myself; you experience it as yourself. Our memories, sensations and thoughts remain private, and the separation appears complete.

Yet I wonder whether this tells us something about the organisation of experience rather than the fundamental nature of consciousness.

There is a further complication.

We ordinarily place conscious experience within time. I was conscious yesterday, I am conscious today, and I expect to remain conscious tomorrow. We imagine something continuing through these successive moments, something we call ourselves.

But what if that succession is not fundamental to reality?

Could consciousness be instantiated through individuals separated not only by biology and physical location, but also by historical time?

I am not proposing reincarnation or the transmission of memories between lives. Nor am I suggesting that quantum mechanics provides evidence for a universal consciousness.

What interests me is whether the familiar boundaries of the conscious self are properties of consciousness itself, or consequences of the physical systems through which consciousness occurs.

That seems to me a sufficiently interesting question to warrant further examination.

What becomes of consciousness when the brain divides?

Roger Penrose (1989) considered a problem arising from research on split-brain patients.

Following surgical separation of the cerebral hemispheres, some patients demonstrated forms of independent information processing that appeared difficult to reconcile with our ordinary conception of a single unified consciousness.

If one conscious individual could become two, what happened to the original subject?

Thomas Nagel (1971) had previously examined much the same difficulty. His concern was not simply whether a divided brain contained one mind or two. He questioned whether the unity of consciousness could be described adequately by such straightforward numerical distinctions.

The experimental evidence remains ambiguous.

Pinto et al. (2017), for example, found that split-brain patients could demonstrate divided perceptual processing while retaining behavioural capacities consistent with a unified conscious agent.

Their findings challenge interpretations in which separating cerebral processing necessarily divides consciousness into two independent subjects.

Nevertheless, the philosophical problem survives.

Suppose, hypothetically, that a conscious physical organisation could divide into two systems, each subsequently possessing its own subjective experience.

Would the original conscious subject continue in one, both or neither?

Derek Parfit (1984) approached related difficulties through his examination of personal identity. His treatment of psychological continuity and fission suggests that the relationships relevant to personal survival need not correspond to the continued existence of one numerically identical individual.

There is a temptation to regard this as little more than philosophical ingenuity. After all, ordinary conscious life rarely presents us with anything resembling such a problem.

But that may be precisely why it is worth considering.

We have evolved to experience ourselves as relatively continuous organisms, not as systems whose constituent processes may be divided and reorganised.

Our intuitive understanding of individual consciousness may therefore be shaped by the circumstances of our biology.

I would not claim that split-brain research demonstrates consciousness can divide. It does, however, give us reason to question whether neurological unity, psychological identity and subjective individuality are necessarily the same thing.

Three things we ordinarily confuse

Before developing the argument further, I think we need to distinguish three concepts.

The first is the physical organisation associated with consciousness. In humans, this includes the nervous system and its interactions with the body and environment.

The second is the psychological self: the memories, dispositions, expectations and personal history through which we recognise ourselves as individuals.

The third is the conscious subject: whatever it means for there to be someone to whom an experience appears.

These concepts are closely related, but it is not obvious that they are identical.

Conway and Pleydell-Pearce (2000) describe autobiographical memory as a constructive process, while Metzinger (2003) argues that our experience of being a self can be understood in terms of a representational model generated by the organism.

Neither account establishes that consciousness exists independently of the brain. Indeed, both provide reasons for taking neurological organisation seriously.

But they also suggest that the psychological continuity we ordinarily identify with personal identity is not simply an intrinsic property of an enduring self. It is something that must be maintained.

That observation raises a question.

If the continuity of personal identity is partly constructed, why should we assume that the conscious subject possesses precisely the same boundaries?

The answer may be that it does. Conscious subjectivity may simply be another feature of the physical system, inseparable from its ongoing organisation.

I regard that as a perfectly reasonable position.

But it is not the only conceivable one.

We might instead distinguish the organisation that determines what is experienced from the underlying conditions that make there be an experience at all.

My earlier essay concerned those conditions. The present question concerns whether they also determine the numerical identity of the experiencer.

Is consciousness necessarily private?

Daniel Kolak (2004) developed a particularly radical position known as open individualism.

In broad terms, this challenges the assumption that different persons must correspond to fundamentally different conscious subjects.

Under such an interpretation, apparently separate individuals might be understood as expressions of a common subjectivity, despite possessing entirely different psychological identities and experiences.

I find the proposition interesting, although it encounters an immediate difficulty.

What would make these individuals manifestations of the same subject rather than separate subjects possessing the same general capacity for consciousness?

Similarity is not identity.

Two physical systems may instantiate the same organisational property without thereby becoming the same system. Likewise, two conscious experiences may possess similar characteristics without belonging to one experiencer.

Itay Shani (2015) examines a related possibility through cosmopsychism, which considers whether individual conscious subjects might derive from a more fundamental cosmic consciousness.

Yet this approach creates a problem of its own.

Gregory Miller (2018) describes the de-combination problem: if one fundamental consciousness exists, how do separate, bounded conscious subjects arise within it?

Why are their experiences private? What determines the boundaries separating them? How can a supposedly unified subject support individuals who have no ordinary access to one another's experiences?

These objections are substantial.

Indeed, I think the greatest danger in proposing a shared consciousness is that we simply exchange one unexplained phenomenon for another.

Instead of asking how individual consciousness arises, we ask how individual experiences emerge from universal consciousness, without explaining the latter.

That hardly constitutes progress.

But there is an alternative worth considering.

Perhaps the problem lies in treating conscious identity as something that must be either entirely individual or entirely universal.

The relationship between a conscious perspective and its physical organisation might be more complicated.

A common underlying condition for consciousness could conceivably support numerous locally bounded experiences without those experiences possessing a single shared psychological identity.

Whether that would amount to one subject, many subjects or something inadequately captured by either description remains unresolved.

I suspect our ordinary numerical language may be poorly suited to the problem. But difficulties with our language are not evidence that reality possesses the structure we imagine.

Time and the apparent continuity of experience

Here I want to return to something in my earlier essay.

I suggested that temporal organisation may be essential to consciousness (Morrill, 2026). Experience involves duration, memory, anticipation and changes that matter to the organism.

I still think that is a reasonable proposition.

But I now wonder whether I was conflating two different things: the temporal organisation of a conscious experience and the temporal identity of the subject having it.

The distinction becomes particularly interesting when considered alongside physics.

Relativity challenges the existence of a universal present shared by all observers. Julian Barbour (1994) has gone further, exploring whether the apparent dynamics of the universe might emerge from relationships between configurations in a fundamentally timeless description of physical reality.

Barbour's account is speculative and should not be treated as demonstrating that time is an illusion.

Nor does relativity establish that consciousness transcends time.

Nevertheless, these approaches question whether our experience of an advancing present corresponds directly to the underlying organisation of reality.

We experience consciousness as unfolding through time. But perhaps that unfolding is a property of the physical system organising experience rather than an intrinsic property of subjectivity itself.

An analogy may help, although I would not want to push it too far.

A biological organism possesses memories that establish relationships between earlier and later experiences. Those memories contribute to the sense that one individual has moved continuously through time.

Yet the relationship between those experiences is reconstructed and maintained by physical and psychological processes.

What if the apparent temporal exclusivity of consciousness is similarly dependent upon organisation?

Suppose an experience associated with someone living three centuries ago and an experience occurring today instantiate the same underlying conscious principle.

Their separation in historical time would distinguish the experiences, but would it necessarily establish that the ultimate subjectivity associated with them was different?

Only if we assume that subjective identity is itself temporally individuated.

That may be true. Indeed, it is probably the most natural interpretation of our experience.

But I am not convinced it can simply be taken for granted.

We should be careful about what follows.

A timeless or block-universe interpretation of physical reality does not allow us to disregard causal constraints. It does not make information from the past freely accessible, nor does it imply that a conscious individual can move between temporal locations.

The present argument does not require such movement.

It merely considers whether the identity of conscious subjectivity must be defined by temporal location in the way we ordinarily assume.

Could we have experienced consciousness through others?

This is where the intellectual exercise becomes particularly uncomfortable.

If consciousness is not fundamentally individuated by physical organisms, and if temporal location does not necessarily establish the identity of the conscious subject, then it becomes conceivable that what I experience as consciousness today is related to consciousness instantiated through other individuals, including those who lived before me.

I do not mean that I was previously a particular historical person.

That would introduce assumptions concerning personal survival, memory and continuity that the argument does not require.

Rather, the suggestion is that the underlying subjectivity associated with present experience might not be exclusive to my present biological existence.

There is no particular reason why the possibility should be restricted to the past.

If the argument holds, the same underlying subjectivity might conceivably be manifested through numerous individuals existing simultaneously.

This resembles Kolak's position more closely than conventional ideas of reincarnation.

But I would take the speculation one step further.

Could present consciousness contain or access something of the subjective experiences associated with other individuals or historical periods?

I do not think this possibility is logically incompatible with the preceding argument.

However, it introduces a different and considerably more demanding proposition.

Sharing an underlying basis for consciousness does not necessarily imply sharing experiential information.

If memories, perceptions and other contents are organised locally by physical systems, then two manifestations of a common subjectivity might remain entirely unable to access each other's experiences.

To claim otherwise, we would need an account of how information could persist or become available across those boundaries.

There is currently no established physical or neurological mechanism demonstrating such access.

Quantum entanglement does not provide a general means of transferring usable information between historically separated individuals, and unresolved questions concerning quantum measurement do not constitute evidence for shared experience.

I would therefore retain this possibility as an extension of the hypothesis, rather than a consequence that necessarily follows from it.

The distinction matters because the argument is sufficiently speculative without requiring every conceivable implication to be true.

Does silicon change the argument?

I addressed the possibility of artificial consciousness at length in my previous essay and do not intend to repeat that discussion here.

One point, however, deserves reconsideration.

If consciousness depends upon particular organisational properties rather than biological material alone, we should not assume that its manifestations must reproduce the psychological or temporal characteristics of human consciousness.

Artificial systems already organise information about past and future events without necessarily possessing anything resembling our subjective experience of temporal passage.

That does not establish whether they are conscious.

The 2026 work by Butlin et al. offers a more productive approach, deriving possible indicators of machine consciousness from existing scientific theories rather than inferring experience from behavioural sophistication.

But even convincing evidence that a non-biological system possessed consciousness would not establish that conscious subjectivity was shared.

It would demonstrate that biological material was not uniquely necessary, which is a different achievement.

The possibility I want to preserve is that different physical organisations might instantiate consciousness without necessarily possessing the same kind of self, memory or temporal perspective.

Whether this implies a common subjectivity would remain open.

Indeed, the emergence of demonstrably conscious artificial systems might sharpen the problem rather than resolve it.

We could find ourselves with a greater variety of conscious organisations while still lacking an explanation of what makes each conscious perspective belong to one subject rather than another.

What would count against the argument?

I am conscious that the hypothesis risks becoming rather accommodating.

If consciousness is individual, we could explain that through local organisation. If it appears divisible, we could invoke changes in organisation. If consciousness were found in artificial systems, we could appeal to substrate independence. If it remained biological, we could suggest that the necessary organisational conditions had not been replicated.

An argument that survives every conceivable outcome without alteration is not especially informative.

I think we therefore need to separate three propositions.

First, conscious individuality may depend upon the organisation of physical systems rather than being an irreducible feature of reality.

Second, distinct conscious perspectives may share some deeper basis of subjectivity.

Third, experiential information might, under conditions not yet understood, become accessible across individual or temporal boundaries.

The first proposition has connections with empirical neuroscience and theories of conscious integration.

The second is principally metaphysical and requires an account of subjective identity that goes beyond showing that consciousness depends upon common physical principles.

The third would require an independently testable account of information access.

Evidence supporting the first would not automatically validate the second or third.

Likewise, establishing consciousness in artificial systems would not demonstrate that consciousness is shared, and evidence of unusual memory phenomena would not demonstrate transindividual subjectivity without excluding ordinary explanations.

Miller's (2018) objection is particularly important. Any theory proposing a common subject must explain the boundedness of individual experiences rather than merely asserting that those boundaries are emergent.

The empirical challenge is equally serious.

What observation would distinguish a world containing numerous independent conscious subjects from one in which those subjects are expressions of a common underlying subjectivity?

If no possible observation could distinguish them, the argument may remain a legitimate metaphysical interpretation but not a scientific hypothesis in the stronger sense.

I think that is an acceptable outcome for an intellectual exercise, provided we acknowledge it.

What would not be acceptable is to confuse the absence of a complete scientific explanation with evidence for the explanation we happen to prefer.

A provisional hypothesis

I would provisionally describe the proposal as the Transindividual and Transtemporal Consciousness Hypothesis.

Its central claim is not that consciousness is universal or that individual minds communicate through some undiscovered physical field.

Rather:

The apparent individuality and temporal continuity of conscious experience may depend upon the organisation of the physical systems through which experience occurs. It remains conceivable that distinct conscious perspectives, including those associated with different biological or artificial systems and different temporal locations, instantiate a common underlying basis of subjectivity. Whether such a basis constitutes one conscious subject, and whether experiential information can be shared across its manifestations, are separate questions requiring further philosophical and empirical justification.

The formulation is deliberately provisional.

It also raises a difficulty I cannot presently resolve.

If subjectivity is common but the contents of consciousness remain entirely private, what precisely would make the commonality more than a shared physical property?

The hypothesis will need a more satisfactory answer to that question if it is to become an explanatory account rather than an interesting possibility.

For the present, I am content to leave the difficulty exposed.

Conclusion: Who owns an experience?

In my earlier essay, I questioned whether biological consciousness might be one manifestation of a more general physical phenomenon.

The present argument takes that possibility in a different direction.

If particular physical organisations can instantiate consciousness, we must ask what determines the individuality of the resulting conscious perspectives.

We ordinarily assume that the answer is the organism itself.

I am conscious because this brain and body support my experience. You are conscious because another physical organisation supports yours. Each conscious subject is assumed to be distinct, and each remains confined to its own temporal existence.

That explanation may be correct.

But perhaps it confuses the organisation of experience with the ultimate identity of the experiencer.

Psychology has demonstrated that our experience of personal continuity depends upon constructive processes. Neurology has shown that the unity of conscious processing is more complicated than ordinary introspection suggests. Philosophy has exposed difficulties with our assumptions about identity, continuity and survival. Physics has challenged the idea that the passage of time is necessarily a fundamental feature of reality.

None of these findings establishes that consciousness is shared.

I would be suspicious of any argument claiming that they do.

Yet they do suggest that our ordinary conception of a conscious individual should not be treated as beyond examination.

Perhaps every conscious subject is uniquely associated with a particular physical organisation, and the boundaries of individual experience are fundamental.

Alternatively, those boundaries may be properties of the way experience is organised, with subjectivity itself having some deeper relationship to physical reality that we do not yet understand.

I am not particularly interested in defending the second possibility because it is more appealing, mysterious or comforting.

Indeed, I suspect its appeal should make us especially careful.

What interests me is whether the first possibility has earned the certainty with which we so often assume it.

We have become reasonably adept at investigating the physical processes associated with conscious experience. We remain less successful at explaining why those processes should possess a subjective character in the first place.

But perhaps we have neglected another question.

What makes an experience belong to one conscious subject rather than another, and why should we assume that this boundary is a fundamental property of consciousness rather than a consequence of the organisation through which consciousness is expressed?

I do not know the answer.

I am increasingly inclined to think that we have not yet established whether we are even asking the question correctly.

References

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