Schrödinger's Vat and the Evolution of Consciousness
27/05/2025
Erwin Schrödinger's famous thought experiment has always been deeply misunderstood. In this article I'd like to explain how, if understood properly, it might shed new light on the mechanism by which consciousness evolved.
Schrödinger's Cat and Schrödinger's Hat
The purpose of Schrödinger's thought experiment was to highlight serious problems in the (then very new) “Copenhagen Interpretation” of Quantum Mechanics (CI). The CI was a bit of a botch-job, because the founders of QM had no idea how to “interpret” the strange new physics they had discovered. The CI says quantum systems remain in a superposition (a “smeared out” state where everything than can happen is somehow happening in parallel) until measured, but does not define what counts as a “measurement”, or why. Schrödinger always rejected this idea, and his thought experiment was intended to demonstrate why. He proposes a sealed box (so no “measurements” can take place), in which has been placed a cat, and a quantum source with a 50% probability of releasing poison. According to the CI, so long as the system inside the box remains “unmeasured”, the poison has both been released and not-released and therefore that cat is both dead and alive. Schrödinger did not believe that reality actually works like this, but very few people understand what he really thought about the nature of reality.
Later in his life Schrödinger wrote extensively about his philosophical beliefs, and made it abundantly clear what he thought consciousness is. He went as far as saying that “Atman = Brahman” was “the second Schrödinger equation” – the thing that is missing from the Schrödinger equation in order to complete our picture of reality. The statement is taken from Vedantic philosophy, and means “the root of personal consciousness is identical to the root of all existence”. To be clear: Schrödinger did not believe in individuated “souls” which can be re-incarnated. He wrote "Consciousness is a singular of which the plural is unknown; that there is only one thing and that what seems to be a plurality is merely a series of different aspects of this one thing...". In other words, there is only one “soul” (or root of consciousness) and it is shared by every conscious being. There is only one of these things, and it is non-physical, eternal and simple. On its own it is not consciousness – it is more fundamental than either consciousness or matter and has no properties apart from its infiniteness.
What are the implications for the cat? Well, now we have to wonder why Schrödinger chose a cat – a live animal which we presume is itself conscious – as the unfortunate subject of his thought experiment. If the cat is conscious then surely it is observing the quantum poison dispenser, and thus the fact the box is sealed is irrelevant, at least from the perspective of the cat, which presumably means the cat is either dead or alive, even before the box is opened. However, we could replace the cat and poison with an equivalent system which isn't conscious – let's say an upturned hat and a bottle of sulphuric acid, which has a 50% chance of being emptied into the hat. Now it looks like maybe we really could have a macroscopic superposition – so long as the box remains sealed, it literally contains a ruined-and-unruined hat.
What does this have to do with the evolution of consciousness?
Firstly, we can be certain that Schrödinger would have said that the Hard Problem of Consciousness has no solution – that it is impossible to explain consciousness purely in terms of a material world. But unlike many modern proponents of that idea, he did not say that consciousness could exist independently of a brain. I repeat: We are NOT talking about “disembodied minds” and NOT claiming that minds can exist without brains. We are saying that brains are necessary for consciousness, but insufficient. So the model of reality we are considering here consists of a brain (which may or may not be in a superposition itself) and a “root” of consciousness – effectively a non-physical internal observer of a brain. This is, in fact, the absolute minimalist solution to the Hard Problem once you've accepted it is impossible to provide a materialistic one. All it adds to the physical picture (to the deterministically evolving wave function) is an “internal observer” of brain activity. No individuated soul, no mind-stuff, just the internal viewpoint which Thomas Nagel also argued was missing from the materialistic conception of reality in his famous essay “What is it like to be a bat?”.
However, this throws up a problem with evolution – a problem which was explored at length by Nagel in his 2012 book Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature is Almost Certainly False. The only thing Nagel said in that book about QM is that it is probabilistic. Nagel argued that brains are (almost certainly) necessary for consciousness, and explicitly rejects idealism (for not taking physical reality seriously enough). He also vociferously rejects the idea that divine intelligence is a likely explanation for evolution or anything else in the universe. However, this leaves us with a humdinger of a problem explaining how the first conscious organism evolved. We can reasonably assume that animals are conscious but nothing else is (that is what nearly everybody actually assumes – nobody treats plants as if they are conscious), so we can tentatively date that first conscious organism to the beginning of the Cambrian Explosion (the first appearance of animals which could sense their environment and respond in real time). How, then, did evolution get from abiogenesis to to the Cambrian Explosion? The problem is that the first conscious animal needed a brain capable of supporting consciousness (we could say “capable of embodying Atman”), but that its immediate ancestors cannot have been conscious at all. If we reject the idea that consciousness = brain activity (or intelligence) then we can't even ask “what use is half a mind?”, because you can't split consciousness into bits. Either the Atman is embodied, and the animal is conscious, or or it isn't, and it isn't. Nagel didn't say anything about Atman and Brahman either, but his book is a tightly argued case for a specific answer to this evolutionary puzzle – that the process of the evolution of conscious life must have been teleological. In other words, that first conscious organism was destined to evolve, and not because God willed or designed it but because somehow that is just how nature works. Nagel says we must now start searching for other examples of natural teleological processes, and ultimately for universally-applicable teleological laws. He suggests that evolution probably continued to be teleological after the first appearance of consciousness, and that this may be the best explanation for why humans have the capacity for (for example) advanced moral reasoning and other value judgements. The scientific community has not exactly embraced these ideas – the most common responses to Mind and Cosmos have been dismissal and outrage.
Schrödinger's Vat
Another thought experiment. This time it involves a gigantic vat – something so large that it can only be constructed in space (think the Deathstar from Star Wars). At the heart of this vat is an infinite energy source (which is physically impossible, but that doesn't matter for the thought experiment) – something which can produce electrical energy, light and heat indefinitely. The rest of the vat contains an “organic soup” – a rich broth of the kind of molecules from which we presume life emerged in the Earth's infant oceans. The vat is a sealed system, and contains no life, and therefore no consciousness. Question: what is the probability that conscious life will naturally evolve in the vat? The vat is in a superposition – all possible combinations of chemical reactions inside it are happening in a massively parallel multiverse. It's not just a biological soup but a quantum soup. This is very much like the Many Worlds Interpretation of QM, except applied only inside the vat. We know it is physically possible (because it has already happened at least once, on Earth), and the thought experiment has set up the conditions where everything which is physically possible actually does happen, eventually. Under these conditions the probability of conscious life evolving in Schrödinger's Vat is surely 100%. How could it not happen, given an indefinite time span and all possible physical outcomes actually happening? We can also say something else – that the moment that this actually happens, the superposition inside the vat would collapse – it would cease to be a quantum soup and start being normal reality. This also implies that it would only happen once – it happens the first time because the quantum dice are 100% loaded in its favour, but once it has happened then the dice can no longer be loaded in this way.
Why this matters
This thought experiment provides us with a naturalistic (i.e. non-theological) explanation for Nagel's teleology, without the need for any teleological laws. In this situation, the telos was structural rather than imposed. In other words, from the perspective of the conscious life that evolves within the vat, something extra-ordinarily improbable has happened – it would appear to have been teleological. Everything happened “just right”, and not because God designed it that way but because that is what such a system would naturally do.
Why does this matter? Because Schrödinger's Vat isn't just a thought experiment. The early universe, before consciousness had had a chance to evolve, was in exactly the state described in the experiment, except instead of there being just one vat there was an unimaginably vast number of vats (thousands of billions of planets). Since there was no consciousness anywhere in the cosmos, it was effectively a cosmic version of the quantum soup containing a superposition of all possible physical outcomes, on every planet in the cosmos. This is almost exactly the same as Hugh Everett's Many Worlds Interpretation of QM – the only difference being that in MWI the different timelines have permanently diverged whereas here we are talking about an uncompleted decoherence (i.e. the timelines are all still intertwined, ready for the day that consciousness evolves, and collapses the superposition by observing it).
This completes Nagel's theory. It doesn't just explain how it was possible for conscious life to evolve – it makes it a 100% inevitability. It had to happen somewhere, and the explanation makes redundant both of the explanations which currently compete: purely random mutations and natural selection, and intelligent design. In effect, the entire cosmos would have naturally functioned like a giant quantum computer, tasked with calculating the sequence of cosmic history required to create conscious life.
Why this really matters.
We can give a name to this hypothesis: the two phase theory of cosmological and biological evolution (from now one just “the two phase theory”). This theory has empirical implications. These implications do not require any new experiments to confirm them. Rather, there are implications for empirical data we are already in possession of, but currently don't have any consensus explanation for.
To recap, the model already provides a solution to three major problems:
(1) The Hard Problem of consciousness. This is solved in the simplest way possible, with the introduction of a non-physical internal observer of brain activity.
(2) The Measurement Problem in QM. This is solved by the same entity (this was John von Neumann's solution to the MP in 1932, as well as Schrödinger's implied solution).
(3) The cause of the Cambrian Explosion. This is now explained as not only the first emergence of conscious life, but a new kind of reality. Nagel is proposing neutral monism, and so we can now say that the Cambrian was the point in cosmological history where the neutral quantum soup gave rise to both consciousness and classical space-time. So we now have a sensible explanation for the empirical data with respect to the CE. This offers a new explanation for the existing empirical data.
But the two phase theory also provides novel solutions to five other problems:
(4) The fine-tuning problem is dissolved. Earth is not a divine creation in an orthodox sense, but it is the first centre of conscious reality, and the centre of the only realised timeline. The mechanism that selected the timeline including abiogenesis and the evolution of consciousness would also have selected our cosmos from all the other possibilities. This offers a new explanation for the existing empirical data.
(5) The Fermi paradox is resolved because the primordial superposition-- the cosmic quantum soup – could only be collapsed once. This makes the empirical prediction that life only exists on Earth, and that we will never find any evidence of alien life. This offers a new explanation for the existing empirical data.
(6) A convincing explanation for the evolution of consciousness and its role in nature now becomes available. The evolutionary process was structurally teleological, and the role of consciousness in wave function collapse provides animals with a new way of interacting with reality – something we have understood intuitively all along but until now could not make sense of.
(7) The problem of free will vanishes. We really do have the metaphysical capacity for free will. Consciousness collapses the wave function, and that means free will decisions can be willed, not determined or random. This restores meaning and value to our model of reality.
(8) The arrow of time is explained. Before the emergence of conscious observers, the universe existed in a time-neutral quantum superposition. In this phase, no definite events occurred – nothing "happened" in the way we understand it, because nothing was observed or measured. The emergence of conscious observers – sentient animals capable of collapsing the wave function – breaks the time symmetry. Wave function collapse is irreversible, and once it begins happening, a direction of time emerges. This is not an illusion – it is ontologically real, arising from the structure of conscious interaction with the quantum substrate. In this view, there is no “flow” of time in the quantum potential itself – just a vast ocean of possible futures and pasts. The Participating Observer navigates this ocean, and in doing so, creates the line of time. This is an asymmetric process: we collapse from many futures into one present, but never from one present into many pasts. Thus, time’s arrow tracks the very act of becoming. Subjective time – our sense of before and after – is not an emergent illusion of entropy; it is a feature of participatory reality, where conscious acts of will shape what is real. The direction of time is entangled with teleology, because every conscious act is inherently directed, purposeful, goal-seeking. This explains why time feels like it moves from the known to the unknown: we are riding the crest of collapsing potentiality.
Conclusion
This hypothesis – the two phase model of cosmological and biological evolution – explains the existing empirical data much better than any existing model does. One simple idea solves eight major problems which currently lurk on the boundaries of science and philosophy. I am not proposing eight different solutions which don't cohere together. I am proposing one solution to all eight problems, which results in a coherent model that solves or dissolves all of them.
PLEASE NOTE: This article is a much shortened and simplified version of an article I posted last week.
For the full philosophical theory this is part of, see my forthcoming book The Real Paths to Ecocivilisation.