https://footnotes2plato.substack.com/p/on-the-possibility-of-cosmology?r=2at642

GPT: Yes. I found it. The paper is “On the Possibility of Cosmology: Spacetime Actualism and the Process-Relational Alternative,” by Matthew D. Segall, Timothy E. Eastman, and Ruth Kastner. It was posted as a draft on Segall's Footnotes²Plato Substack apparently ahead of presentation at the 14th International Whitehead Conference in Zhuhai.

I've read through the actual text. My short verdict is:

It's an interesting and in places genuinely sophisticated piece of philosophy of physics, but I don't think it succeeds in establishing its central claim that spacetime actualism is metaphysically incoherent. Its strongest arguments are philosophical critiques of reductionism and reification; its weakest move is turning those critiques into purported consequences for contemporary cosmology and quantum physics.

And there is one particularly important issue: the paper sometimes moves too quickly from “physics does not describe X” to “X must therefore have ontological status.” That is a much bigger philosophical step than the authors acknowledge.

What the paper is actually arguing

The argument has roughly this structure:

1. Modern physics represents physical reality using spacetime and mathematical structures.
2. Some physicists/philosophers allegedly treat those mathematical structures as the whole of reality.
3. Segall, Eastman and Kastner call this “spacetime actualism.”
4. Whitehead's philosophy says this is an instance of the “bifurcation of nature”—mistaking an abstraction made for scientific purposes for the concrete reality from which it was abstracted.
5. Actual spacetime descriptions cannot adequately represent:
   • becoming,
   • genuine possibility,
   • value,
   • experience,
   • consciousness,
   • scientific reasoning itself.
6. Therefore, the ontology underlying spacetime physics must be enlarged.
7. They propose a process-relational ontology, drawing heavily on Whitehead.
8. Quantum theory, particularly Ruth Kastner's Relativistic Transactional Interpretation (RTI), is presented as evidence that spacetime events may emerge from a deeper realm of real possibilities/potentiae.

That's a coherent philosophical project.

But there are several different arguments embedded within it, and they don't all have the same strength.

---

1. The Whitehead argument is genuinely interesting

The best part of the paper, in my view, is the application of Whitehead's distinction between coordinate analysis and genetic analysis.

The authors essentially say:

Physics is extremely good at telling us how actual events relate to one another, but that doesn't necessarily mean its coordinate description captures what an actual event is in its becoming.

That's a legitimate philosophical point.

Imagine a weather map.

A weather map can tell you:

• temperature,
• pressure,
• wind velocity,
• humidity,
• geographical position.

But the map isn't literally the weather.

The authors argue that something analogous happens when we take the mathematical representation of physical events and promote it from:

“an extraordinarily successful abstraction of nature”

to:

“the complete ontology of nature.”

That's basically Whitehead's fallacy of misplaced concreteness applied to modern physics.

I think this is the paper's strongest philosophical insight.

And importantly, you don't have to accept Whitehead's metaphysics to accept the warning.

A physicist can perfectly reasonably say:

“General relativity gives us an extraordinarily successful mathematical description of gravitational phenomena.”

That does not automatically entail:

“The mathematical spacetime manifold is literally all that exists.”

Those are different claims.

So the authors are right to distinguish physical theory from metaphysical interpretation of physical theory.

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2. But then comes the big leap

The paper repeatedly makes an argument roughly like this:

Cosmologists are themselves conscious beings who entertain possibilities. Therefore a cosmology that describes only actual spacetime events cannot account for the possibility of cosmology itself.

This is clever.

But I don't think it establishes what the authors want it to establish.

Consider a conventional physicalist response.

A physicalist can say:

“Of course cosmologists are physical systems inside the universe. Their brains instantiate physical states that represent hypothetical possibilities.”

Nothing contradictory follows.

The fact that I can imagine a unicorn doesn't require the unicorn to exist.

Likewise:

My brain representing possibility doesn't necessarily imply that possibility itself has independent ontological existence.

This is probably the most important weakness in the paper.

The authors explicitly anticipate this objection. They say that if the brain merely represents possibilities, then the theory still needs an account of how representation can be about something that isn't ontically real. They invoke Whitehead's criticism of representationalism.

That's a respectable philosophical argument.

But it's not a knock-down argument.

It assumes a particular theory of representation and then argues that representation requires something like Whiteheadian “conceptual prehension.”

A physicalist can simply reject that premise.

For example:

A neural system can represent counterfactual states because its physical architecture supports counterfactual modelling.

You might dislike that explanation, but it isn't obviously self-contradictory.

So I'd rate this argument:

Philosophically provocative: 8/10
Demonstration that physicalism is incoherent: 3/10

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3. The “possibility must be real” argument

This is the heart of the paper.

The authors want possibility to be ontic, rather than merely epistemic.

In other words:

Possibilities aren't just things minds imagine because they don't know what will happen.

There are genuinely possible futures built into nature.

This is a serious philosophical position. It has a long history and isn't remotely crazy.

The authors distinguish:

• pure potentiality
• real potentiality

and connect this to Whitehead's eternal objects and the actual/potential distinction.

I actually think this is more defensible than some critics might initially assume.

Quantum mechanics certainly gives us reason to take counterfactual possibilities seriously. The question is what those possibilities are.

But here's the crucial point:

Quantum indeterminacy doesn't automatically entail Whiteheadian ontology.

You could have:

Interpretation A

Quantum possibilities are real physical possibilities.

Or:

Interpretation B

The quantum state is a mathematical object encoding probabilities of possible observations.

Or:

Interpretation C

Many possible outcomes correspond to branches of an Everettian wavefunction.

Or:

Interpretation D

There is some deeper ontology underlying the quantum formalism.

All of these are live philosophical possibilities.

The paper sometimes writes as though quantum mechanics itself has already forced us into something close to Whitehead's ontology.

It hasn't.

That's an interpretive argument, not an empirical conclusion.

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4. The quantum section is where I become much more sceptical

The authors use Kastner's Relativistic Transactional Interpretation (RTI) as their principal physical example.

The basic picture is fascinating:

• quantum possibilities exist in a pre-spacetime domain;
• transactions actualize particular events;
• spacetime events emerge from those actualizations;
• the underlying potentiality is more fundamental than spacetime itself.

That fits Whitehead beautifully.

But there's a potential circularity here.

The paper essentially says:

Whitehead predicts that reality should have this process/potential structure.

Then:

Kastner's interpretation of quantum theory has this process/potential structure.

Therefore:

Kastner's interpretation provides physical support for Whitehead.

That's suggestive.

But it isn't confirmation.

Because RTI is itself an interpretation of quantum theory, rather than an experimentally established discovery of a pre-spacetime realm.

The authors acknowledge that it is a candidate physical theory and emphasize its quantitative character.

But the paper could do much more to distinguish:

“This interpretation is mathematically/physically viable”

from:

“Experiments demonstrate that reality actually has this ontology.”

Those are very different claims.

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5. The Big Bang section is even more controversial

This is probably the part I'd push back against most strongly.

The authors use Timothy Eastman's critique of the Big Bang research programme and discuss plasma cosmology as an alternative.

They argue that if the Big Bang singularity is an artefact of extrapolating a mathematical model beyond its legitimate domain, then the question of the ultimate origin of the universe cannot be settled simply by running the equations backwards.

There is a legitimate point here:

A mathematical singularity doesn't automatically mean that nature literally contained an infinitely dense point.

Physicists themselves know this.

A singularity often tells us:

“This theory has reached a regime where its assumptions break down.”

So the philosophical warning is fair.

But then the paper moves toward presenting plasma cosmology as a serious alternative.

That's where I'd want considerably more empirical engagement.

The standard cosmological model isn't accepted merely because physicists are philosophically committed to spacetime actualism.

It has an enormous empirical record behind it:

• cosmic microwave background observations,
• primordial nucleosynthesis,
• large-scale structure,
• baryon acoustic oscillations,
• supernova distance measurements,
• gravitational lensing,
• expansion history,
• etc.

The paper doesn't actually overturn that evidence.

And the authors themselves explicitly say:

“We do not adjudicate that empirical contest here.”

That's intellectually honest—but it also means this section can't function as empirical confirmation of their metaphysics.

At most, it shows that there are philosophical reasons to question whether the standard cosmological model should be interpreted ontologically.

That's a much weaker claim.

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6. There is a fascinating self-referential argument

One thing I particularly liked is the paper's argument about scientific reasoning itself.

Suppose the universe is completely fixed.

Every event is already part of a four-dimensional block.

Then the cosmologist sitting here in 2026:

• considers theory A,
• considers theory B,
• evaluates evidence,
• rejects A,
• accepts B,

is itself simply another physical event inside that block.

The authors ask:

What is the ontological status of the “could have been otherwise” involved in that reasoning?

That's a genuinely interesting question.

If I say:

“The data could have supported hypothesis A, but they instead support B,”

what exactly does “could have” mean?

Is it:

1. a statement about our ignorance?
2. a counterfactual about physical laws?
3. a real physical possibility?
4. something encoded in quantum mechanics?
5. something irreducible to physical description?

The paper wants answer #3.

But the paper hasn't demonstrated that #3 is the only coherent answer.

That's the philosophical battleground.

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7. The strongest criticism I would make

The paper repeatedly commits what I'd call a scope-to-ontology transition.

It starts with:

“Physics abstracts away from X.”

That's obviously true.

Then:

“Physics therefore doesn't explain X.”

Often true, depending on X.

Then:

“Therefore X cannot be reduced to the physical.”

That is much more controversial.

Then:

“Therefore X must have independent ontological status.”

That's another major step.

And finally:

“Whitehead's ontology provides the correct account of that status.”

That's another step again.

So you have:

physics doesn't describe X

→ physics doesn't explain X

→ X isn't reducible to physics

→ X is ontologically fundamental

→ Whitehead correctly describes X

Each arrow requires an argument.

The paper sometimes moves through these transitions too quickly.

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8. Nevertheless, I don't think it's pseudoscience

This is worth saying clearly.

Having read the actual paper, I wouldn't classify it as pseudoscience.

It's a speculative philosophy-of-physics paper that tries to construct a bridge between:

• Whiteheadian process philosophy,
• philosophy of science,
• quantum foundations,
• cosmology,
• emergence,
• consciousness,
• and metaphysics.

That's legitimate intellectual territory.

Its problem is not that it asks ridiculous questions.

Its problem is that some philosophical conclusions are presented with more inevitability than the arguments warrant.

There's a big difference.

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My scorecard

If I were reviewing this for a philosophy-of-physics journal, I'd roughly give it:

Dimension	My assessment
Originality	8/10
Philosophical ambition	9/10
Exposition	8/10
Whitehead scholarship	8/10
Critique of naïve reductionism	8/10
Argument for ontic possibility	6/10
Argument against physicalism	4/10
Quantum-physics argument	5/10
Cosmological argument	4/10
Empirical support	3/10
Overall	6.5–7/10

I'd regard it as worth reading, particularly if you're interested in Whitehead, process philosophy or foundations of physics.

But I would not come away believing that the authors have demonstrated that spacetime is derivative, that possibility is ontologically fundamental, or that contemporary cosmology is metaphysically incoherent.

They've made a case for taking those possibilities seriously.

That's different.

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One thing I find particularly interesting

Given what we were discussing about Jason Arday, there is actually a useful methodological contrast here.

This paper is quite explicit that it is making a philosophical/metaphysical argument, and it generally tells the reader when it is moving from established physics into interpretation. That makes it much easier to evaluate.

The interesting question with Segall is therefore not:

“Is this scientifically proven?”

It isn't.

The better question is:

“Does the Whiteheadian metaphysics actually follow from the problems in contemporary physics that the authors identify?”

My answer is partly, but not nearly as strongly as the authors suggest.

And if you want to really stress-test it, the next thing I'd recommend is not another review of the paper. I'd take its central syllogism and attack it from the other side: what would a serious contemporary physicist/philosopher such as Sean Carroll, David Wallace, Carlo Rovelli, or Tim Maudlin say is wrong with Segall's argument? That would reveal very quickly which parts are genuinely profound.