I think the second quote is an articulation of the first. It would make sense for the religion of one's cultural background to capture something the others don’t. Not that the reverse isn’t sometimes true for some people. — Tom Storm

I see what you mean, but I would say that this is a bit overly reductionistic. People choose to align themselves to religious traditions for many reasons that cannot be reduced solely to the influence of their cultural backgrounds.

have never understood the resurrection story, or, as some put it: God sacrificed Himself to Himself to save us from Himself because of a rule He made Himself.

That may be a bit glib, but the blood sacrifice element never made sense to me. The fact Jesus could walk away from it just demonstrated how little was sacrificed, he was omnipotent to begin with. No doubt there are innumerable theological exegeses to offer to redeem (sorry) this account. — Tom Storm

Again, I would say that this is probably overly reductionistic and perhaps even a bit uncharitable. I think that "blood sacrifice" is not the best historical description of how the earliest Christians understood the crucifixion. The language of sacrifice is indeed one of several interpretive strands running through the tradition, but (as far as I know) it was not understood by early Christians as an expression of primitive blood magic. The crucifixion (and the resurrection) were seen primarily as a symbolic condemnation of violence, not a sacralization of it.

That said, I lean more toward the first analysis than the second. Is it possible to doubt whether I have two hands? Yes. Do we know the general sorts of things that justify our (comparative) certainty about two-handedness? Yes. — J

My analysis would actually be closer to the second than the first, and I largely agree with 's reply, though I framed it differently. The basic idea is that some "why?" questions misfire because they try to put into question that which makes questioning possible in the first place. Framed like this, it can be seen as a retorsion argument, or argument from pragmatic contradiction.

Cheers. I saw your farewell in another thread and won't tether you to the forum with another reply. I wish you the best of luck with your novel. Hopefully we'll get the chance to converse again sometime in the future. It's been a pleasure. Take care.

I often wonder, in such cases, why Christianity rather than Hinduism, Islam or Buddhism. When read deeply, they too offer cast contemplative opportunities. — Tom Storm

Indeed they do, and it's a good question. I'm guessing that Allison would concede that his affinity for Christianity is rooted in his cultural background. I know that he has engaged honestly with other traditions and I don't think he would try to say that Christianity is demonstrably superior to them according to any neutral, public criteria. That said, he also seems to think that the Christian tradition captures something unique that helps him to make sense of the world in a way not replicated by other traditions, and that the resurrection plays a role in that. I'm not sure if he'd be willing to say anything stronger than that.

The term "intentional object" describes a role rather than an entity. I realize that the terminology in my previous post was ambiguous, so I'll try to spell it out more clearly.

The VR game has virtual game-objects. The game-objects are entities in their own right, realized by (but not reducible to) hardware, software and norm-governed social practices.

We also have the agent who is perceiving the game-objects. Like the game-objects, the agent is an entity in its own right, realized by (but not reducible to) biological processes and norm-governed social practices.

When game-objects are perceived and interacted with by the agent they function as intentional objects. This function is realized by the norm-governed relation between the game-object, the agent, and publicly accessible practices of perception-and-action. This relation is itself not reducible to the physical processes that realize either the game-object, the agent or their physical interaction.

So in cases of veridical perception the intentional object just is the game-object under a mode of access.

I've met similar people and even identified as one for a short time. I get the impression, though, that Allison would likely reject he NOMA label. While he denies that historical method can establish the resurrection, I think he would accept that historical method nevertheless constrains belief. I think he is saying something more like "history places limits on what can responsibly be believed, but it does not exhaust rational judgment". My impression is that he would reject the resurrection if, say, the skeletal remains of Jesus were to be found. Barring something like that, he sees his belief as responsible judgment under evidential underdetermination, constrained by history but not produced by it -- or something like that.

Again, keeping it very brief, I would say that the virtual objects are intentional objects. They are not reducible to material objects situated outside the body, computer software or neurological activity, though they are realized via the interaction of all three. Intentional objects are constituted within a rule-governed, publicly accessible practice of perception and action. They are subject to constraints of normative correctness, public criteria of identity, action guidance and counter-factual robustness.

If a bionic eye, as well as being able to help the otherwise-blind navigate the real world, can be used to play VR computer games, then what, if anything, do we see when we use it to play VR computer games?

I'd be interested in what you think @Esse Quam Videri. I don't intend to start a new debate so won't argue against anything you say, just curious. — Michael

Sure. Feel free to respond or not at your discretion. I don't mind seeing the conversation continue, though I suspect we'd probably end up at the same place again. :smile:

Very briefly, I would say that when using a bionic eye to play a VR game we see a virtual environment populated with game-world objects. I would say that we do not see things like "phenomenal qualities", "mental pictures" or "electromagnetic radiation", but the virtual objects and environments themselves.

- I've been meaning to return to this for a while now, but just haven't had time. You're already juggling multiple interlocutors; hopefully this won't be interpreted as "piling on".

For example, imagine that there is forty chairs in a room somewhere. There is simply an existing bijection between the chairs and the integers, so that the count is already made without having to be counted. It's just a brute fact that there is forty chairs there, without anyone counting them. This is a form of realism known as Platonic realism. The numbers simply exist, and have those relations, which we would put them into through our methods, but it is not required that we put them into those relations for the relations to exist. — Metaphysician Undercover

I see what you are saying here. I was coming at this from a slightly different angle.

I take it that you are aware that there are several different axiomatizations of set theory. Some examples are: ZFC, ZF, Z, CZF, IZF and various Finitistic and even Ultrafinitistic systems.

The argument about measurement that you provided in your reply is interesting, and I can see how it is relevant to question of whether (or in what sense) a countably infinite set can be said to "exist". But the word "exists" can have different meanings depending on the context. Within the context of ZFC set theory, to say that a countably infinite set "exists" doesn't imply that it exists in some Platonic heaven. That's not to say that you couldn't interpret it in a Platonic way, just that nothing in ZFC itself forces this interpretation.

Now, I see that a few others on the thread have raised a similar point and that you have not been convinced. That's fair. I doubt that I will be able to convince you either, but I will try to explain how I see it and then you can let me know what you think.

The way I (and many others) interpret the word "exists" with respect to ZFC set theory is something like "there is a derivation from the axioms of ZFC using the inference rules of classical first-order logic, of the formula ∃x P(x)". Or, more compactly, ZFC ⊢ ∃x P(x).

So to say that "a countably infinite set exists" is just to say "ZFC ⊢ ∃x CountablyInfinite(x)". The actual derivation follows very simply from the axiom of infinity in combination with the definition of "countably infinite".

In my view, accepting this does not mean that you have to believe that countably infinite sets "exist" in any other sense, whether that be in a Platonic heaven, in the mind of God, or as an actual collection of objects somewhere within the physical universe.

What are your thoughts on this?

Are you saying that when you look at a table, you perceive the spatial relation between the table top and table legs indirectly? — RussellA

Presentism does not say there is only one time, it says that entities exist only at the "present" time.

I don’t understand how the Sun can persist through different times when in Presentism there is only one time, namely the present. — RussellA

No, I would say that the spatial relation is not "perceived" in the sense of being a datum of experience.

We need to learn the names "yellow" and “circle”, but I would have thought that our ability to perceive yellowness and circularity are innate, something we are born with. — RussellA

The capacity to experience colors and shapes is innate for people born with "normal" perceptual systems. But "yellow" and "circle" are more than just names, they are concepts that have to be understood through personal insight and stabilized through social practice.

I would appreciate it if sometime you could find any flaws in my main argument against Direct Realism (both Phenomenological Direct Realism (PDR) and Semantic Direct Realism (SDR)). — RussellA

Here is some feedback regarding your argument. I'll go step-by-step stating whether I accept or reject along with some brief notes about why:

1. Accepted.
2. Accepted.
3. Rejected: I would not claim that “content travels unchanged” through the chain. I would claim that perception is of the object via the chain, not that the chain preserves representational content.
4. Accepted with qualification: I accept sensory dependence, but deny that this entails mediation by inner objects or representations.
5. Rejected: This establishes at most epistemic underdetermination, not logical impossibility; the examples show fallibility, not impossibility.
6. Rejected: Fallibility or inferential uncertainty does not entail logical impossibility; this confuses limits on reconstruction with limits on knowledge.
7. Rejected: Non-sequitur. Even if causal origins cannot be reconstructed with certainty, it does not follow that the object of perception is an inner phenomenal item rather than the external object.
8. Granted.
9. Rejected: False attribution. I do not claim we can logically reconstruct prior causal links; I claim that perception is world-involving without requiring such reconstruction.

But I’m not sure about this; so many skeptical challenges can be interpreted not as questioning a hinge proposition but simply as demonstrating that our language allows us to ask “Why?” about pretty much anything. — J

I am not responding on behalf of Sam26 here, but I would say that asking "why?" is not itself an epistemically "innocent" act. It assumes that there is something to ask "why" about, admits the possibility of finding an answer, and presupposes that some answers will be better than others, among other things. To ask "why" is already to make a move within the game. Would you agree?

Thanks for the very well-written OP.

I'm curious how you think your argument would land with the historian Dale Allison. Are you familiar with his book on the resurrection?

My understanding is that Allison would largely grant everything that you said with regards to the weakness of the testimonial case for the resurrection, but would push back is on the implicit assumption that if a claim fails to meet public historical standards of testimonial knowledge, then that belief lacks adequate epistemic warrant simpliciter.

He seems to argue along the following lines:

(1) The resurrection is not an inference to the best explanation
(2) The resurrection is a singular event that resists historical capture
(3) Belief in the resurrection arises from a convergence of factors, not historical evidence alone

With regards to (3) specifically he seems to say that belief in the resurrection is more akin to committing to a total vision of reality or interpreting history through a larger horizon. He often frames belief as a reasonable risk in light of the moral vision of Jesus, the coherence of Christian hope and the way the resurrection belief "fits" into a total viewpoint, etc.

What are your thoughts on this type of approach?

:up:

I'm familiar with the diagram you presented and with McDowell's position. Although I am heavily influenced by McDowell, I part ways with him on the question of perception.

I don't accept your claim that we are forced to choose between naive realism and indirect realism as you have laid them out. Neither do I accept your claim that my view qualifies as SDR as defined by the paper you've referenced. I'm not sure where that leaves us.

I think you're reading too much into the word "object" — and note that I didn't even use the word "object" in the context of mental phenomena. — Michael

I'm just trying to interpret your language, which I find to be a bit opaque. In (2) you said that colours and pain are directly "present to" something -- "the mind" -- and that they are present "in" phenomenal experience. This language is strongly evocative of objects being present in a space to some observer. I'm just trying to figure out why we would use any of this language if we don't mean something like this.

Whatever pain is, it is a literal constituent of phenomenal experience, unlike the fire that is causally responsible for this phenomenal experience by burning the nerve endings in my skin. — Michael

Just trying to understand: you said in (1) above that pain is a mental phenomena. In the quote directly above, you've said pain is a "constituent of" phenomenal experience. This evokes a part-whole relationship. Is pain one part of a larger composite "thing"; namely, phenomenal experience?

Are you saying that direct and indirect realists are using the word "perception" wrong?

...Or are you saying that direct and indirect realists are...are wrong about what would satisfy "direct perception" and about what would satisfy "indirect perception"? — Michael

Neither. By "misdefined", I'm saying that the whole traditional debate presupposes a mistaken "object-presentation" model of experience. By "wrong level", I mean that I don't think that "experience" is the level at which object-directedness occurs.

I don't know how to answer that. — Michael

I’m not asking how information is causally transmitted or how the brain interprets signals. I’m asking how experiential data bear epistemically on judgment—i.e., whether they function as reasons, conditions for insight, or merely as causes.

For there to be a token identity between the features of the experience and the features of the thing experienced. — Michael

I'm puzzled by this. How does this definition apply to the white circle? What is the white circle token-identical with such that it can satisfy your criterion?

The IR is saying that i) there is no stick in the mind-external world in the first place, ii) the fact there is no stick in the mind-external world is what implies indirectness, iii) the stick we perceive exists as a concept in the mind, not as a fact in the mind-external world. — RussellA

Yes, but none of this follows from anything else you've said so far. I don't deny the IR the right to believe these things, I only deny that they are rationally compelling.

For the DR, the Sun exists in the mind-external world. Accepting Presentism, an object cannot persist through different times when only one time exists. The tensed truth “The Sun exists now” is true now has no relation to “the Sun persists now”. — RussellA

Tensed truths are not only about the present, but about the past and future as well. Presentism doesn't rule out tensed truths about persistent objects.

I would appreciate it if sometime you could find any flaws in my main argument against Direct Realism (both Phenomenological Direct Realism (PDR) and Semantic Direct Realism (SDR)) — RussellA

I will try to get back to this when I get some time.

Suppose that many times I perceive the combination yellow circle. — RussellA

I think that your account of experience, understanding and judgment is overly simplistic and elides many important distinctions. For example, what does it mean to "perceive" the "combination" or "yellow" and "circle"? A "combination" is a relation. Are you saying we can perceive relations directly? "Yellow" and "circle" are classifications. Do these just "appear" within consciousness without any effort or learning on the part of the subject?

Reject what specifically?

1. That colours and pain are mental phenomena
2. That colours and pain are directly present to the mind in phenomenal experience
3. The transitive law that therefore mental phenomena are directly present to the mind in phenomenal experience
4. That distal objects are not directly present to the mind in phenomenal experience
5. That the phrase "to directly perceive X" as used by traditional direct and indirect realists means "X is directly present to the mind in phenomenal experience" — Michael

I pretty much reject all of them as stated. I'll be brief:

(1) Rejected because it reifies experiential data into mental objects.
(2) Rejected because experience is not object-presentation.
(3) Rejected because the ontology and the inference both misdescribe consciousness.
(4) Rejected because experience is not object-presentation, whether distal or proximal.
(5) Rejected because it misdefines perception at the wrong level of analysis.

Are you asking about the binding problem? We don't have a good explanation of that yet. — Michael

No, I'm not asking about neural mechanisms, I am asking about the epistemic relationship between the two.

Taken from the problem of perception, "the character of your experience is explained by an actual instance of [a white circle] manifesting itself in experience". — Michael

On this view, what is the difference between a white-circle "manifesting" itself within experience and a boat "manifesting" itself in experience?

The DR agrees that they perceive a Sun because of a causal chain, but as it is logically impossible to know what initiated any causal chain arriving at our senses, what the DR is perceiving cannot be something in the mind-external world.

If the DR is not perceiving a “worldly object”, then they can only be perceiving something in their mind. — RussellA

This does not follow. You are trying to argue from epistemic limits to an ontological conclusion. Even granting the contestable claim that it is "logically impossible" to know what initiated the causal chain, all that follows is that we can't be certain of what we perceive. Fallibility doesn't imply indirectness.

But how can something persist in a mind-external world, if persists means exists at different times, and in Presentism only one moment in time exists — RussellA

Persistence on Presentism is cashed out in terms of tensed truths and causal continuity, not simultaneous existence at multiple times.

I thought that DR requires that perception is grounded in a mind-external object. This mind-external object may in fact initiate a causal chain, but it is not the causal chain that the perception of the DR is grounded in. — RussellA

The causal chain doesn't interpose something between subject and object; it's the means by which the object is perceptually available.

In what sense is judging that in the mind-external world there is a Sun different to inferring from my sensations that in the mind-external world is a Sun? — RussellA

Judgment is the movement from sensory data to existential affirmation by way of insight and understanding, whereas inference is a movement from premises to conclusion by way of logical rules.

The indirect realist's claim is that pain and colours are mental phenomena and are directly present to the mind in phenomenal experience, whereas a truck is a machine that exists at a distance from the body and is not directly present to the mind in phenomenal experience, and so therefore perception of mental phenomena is direct and perception of trucks is not direct (is indirect) — with perception of trucks only made possible by the perception of mental phenomena. — Michael

I believe this is where we keep talking past each other. I reject the above.

Out of curiosity, for the indirect realist described above, what is the relationship between multi-modal sensory data (redness as-seen, loudness as-heard, etc.) and the judgement that expresses the claim “that’s a truck”?

Also, what does it mean to say that multi-modal sense data are “directly present” to the mind?

Once again, this shows that you are arguing for semantic direct realism, which is distinct from phenomenological direct realism and compatible with phenomenological indirect realism. — Michael

And once again, I disagree for reasons we have already discussed.

First, I don’t categorize myself as an SDR; at least, not in the way that Robinson defines it.

Second, in the traditional debate both direct and indirect realists assume that some kind of object is directly present to the mind through phenomenal experience, whether worldly or intermediary. I reject that assumption.

That’s why the painting analogy fails. For me, experience does not represent or manifest the world at all. Experience supplies data within a normative structure of inquiry; it does not function as a representation or as an object of awareness in its own right.

Also, the analogy obscures my point about normativity. Paintings can misrepresent because there's a convention connecting paint-patterns to subjects. But perceptual error is not a failure of representational convention, but a failure to satisfy correctness conditions—conditions that are constitutively world-involving, not products of representational convention.

Why? You're just begging the question again. I'll just respond by saying that in (2) the strawberry is the object of intentionality and the visor is part of the causal infrastructure that realizes the intentionality. Where do we go from there? — Michael

If you respond that way then the dispute has been elevated from a question of where the visor fits into the causal chain to a dispute over what counts as the intentional object of perception. At that point, the only coherent way to adjudicate the claim is by taking an "intentional stance" toward the system - treating it as a normative, agential entity rather than as merely a causal chain. It is only at that level of resolution that the question "what is the object of the system's perception?" makes any sense, since questions of aboutness, reference, and error only arise at that level of analysis. They are not facts that drop out of wiring diagrams.

Now, you could refuse this move, but then the burden would be on you to explain intentionality without appeal to normative or agential notions—or else to accept some kind of eliminativism.

In (1), the visor is not itself the object of intentionality. It is part of the causal infrastructure that realizes intentionality.

In (2), the visor is itself the object of intentionality. The subject’s perceptual state is about what the visor presents.

My point is that intentionality is not reducible to causal structure, though it is realized by it. That’s why adding or removing links in a causal chain is irrelevant unless it forces a change in what the perceptual state is about—that is, in the boundaries of the intentional system itself. And because intentionality is not reducible, there is no principled way of cashing that distinction out purely in causal terms.

The Indirect Realist (IR) and Direct Realist (DR) agree
1 - There is a temporal causal chain that follows the laws of physics from a mind-external something to perceiving the Sun in the mind. — RussellA

I don't accept this phrasing "perceiving the Sun in the mind" if it implies that perception is of some sort of mental item.

Beliefs of the IR and DR
1 - The Direct Realist believes that there is a one to one correspondence between the Sun we perceive in the mind to a Sun that both exists and persists in the world. — RussellA

Likewise, I didn't accept this. It suggests that what is perceived is a mental item (a Sun-in-the-mind) and that perception involves matching that mental item to a worldly object.

Something in the mind-external world that is constantly changing cannot persist. — RussellA

This doesn't follow. Physical systems persist precisely by changing in structured ways.

2 - In the arrow of causation, given a present event, we can determine a future event using the laws of physics, but it is logically impossible to determine a past event. — RussellA

DR doesn't require this. It requires only that perception be grounded in lawful causal dependence on the world.

As knowing a past event using a temporal causal chain is logically impossible, only by inference from the present can a past event be hypothesised. This is the position of the IR. — RussellA

I think you are missing the point of the regress argument. At some point, something must count as non-inferentially present to the mind, or explanation never begins.

I don't understand what you mean by saying that the standard is normative. — Michael

I'm making a distinction between error and malfunction. Error is about failure relative to how the world is. Malfunction is about failure relative to how a system normally operates. I'm saying the former is not reducible to the latter.

The reason it can feel like the goalposts are shifting is that your scenarios quietly presuppose that all failure is just malfunction. But that’s exactly what I’m denying. Whether a device (organic or bionic) is constitutive of perception or merely instrumental within it depends on the role it plays in making representation—and therefore error—possible at all with respect to the subject. Causality can only explain malfunction. We need normativity in order to explain error.

The criterion is normative, not causal: a system is constitutive if it fixes what perceptual correctness means for the subject, instrumental if its outputs are assessable against an already-defined standard. Here “fixes” is not meant causally, but normatively: it determines what counts as seeing correctly rather than incorrectly for the subject. Wiring diagrams underdetermine this, which is why your cases (3)–(6) can't be resolved by causal structure alone—each could go either way depending on which system, if either, fixes the perceptual norm.

So 'fixed at birth' and 'bypasses' don't answer the question; what matters is whether there's an independent standard against which the system's outputs are intelligibly assessable. If you reject that distinction—if you think causal covariance exhausts perceptual normativity—then the question dissolves, but so does the notion that any system could misrepresent rather than merely malfunction.

This still seems like special pleading. You're arguing... — Michael

I think there’s a misunderstanding here about what I’m actually committed to, and it’s generating the appearance of an asymmetry that I don’t accept.

I’m not committed to the pattern you attribute to me. On my view, the symmetry holds at the level of replacement. In particular:

(1) Starting with only a visor → direct perception relative to the visor.
(2) Starting with only eyes → direct perception relative to the eyes.
(3) Replacing a visor with eyes, where the eyes now fix perceptual normativity → direct perception relative to the eyes.
(4) Replacing eyes with a visor, where the visor now fixes perceptual normativity → direct perception relative to the visor.

So there’s no device-based asymmetry here at all. Eyes and visors are on a par in principle. I've not been denying this.

What I’ve been denying is a different claim, which your formulation runs together with (4):

(4*) Adding a visor that intervenes on an already-functioning eye-based perceptual capacity—without replacing it as the system that fixes perceptual normativity → indirect perception relative to the visor.

The crucial distinction is not eyes vs visor, but replacement vs intervention. A system counts as constitutive of direct perception only when it defines what counts as perceptual correctness for the subject at that time. A system that operates against the background of an already-defined perceptual capacity is instrumental, and its outputs are intelligibly assessable as succeeding or failing relative to that background.

This applies symmetrically. If someone initially perceived only via a visor, and eyes were later added in a way that merely intervened on that visor-based capacity, then perception would remain direct relative to the visor and indirect relative to the eyes. There’s no privileging of biology here.

What’s been doing the work in our disagreement is that your original case (4) was underspecified between replacement and intervention, and I think that you and I have been reading it differently. Once that ambiguity is resolved, the alleged inconsistency disappears. The view is role-relative, not device-relative, and it treats eyes and visors in exactly the same way.

I think the “if and only if” formulation still overgeneralizes, and the reason is that it abstracts away from the role a system is actually playing at a given time.

What I’ve been claiming is this: at any given time, whatever system is fixing the space of perceptual normativity for the subject constitutes direct perception relative to that system. That does not imply a biconditional across all possible rewiring histories.

So yes:
– If a subject initially has only eyes, perception is direct relative to the eyes.
– If a subject initially has only a visor, perception is direct relative to the visor.

But it does not follow that (2) is direct perception if and only if (4) is direct perception in the original cases you described. In (4) as originally formulated, the visor was introduced as an intervention on an already-functioning perceptual capacity, not as the system that fixed perceptual normativity for the subject. That is exactly what made it instrumental rather than constitutive in that case.

Your rephrasing changes the scenario in a substantive way. If the visor genuinely bypasses the eyes and wholly replaces them as the system that fixes perceptual correctness for the subject, then yes, in that revised scenario, perception would be direct relative to the visor. But that is no longer the original (4). It is a different case with a different role-assignment.

So the disagreement is not about whether eyes and visors can ever be on a par in principle—they can. It’s about whether, in a given setup, a system is functioning as the constitutive basis of perception or as an intervention on one. Once that distinction is kept fixed, the “if and only if” claim does not go through.

More generally, this is why I’ve been resisting the idea that directness can be decided by gadget-swapping alone. Directness is not a property of devices considered in isolation, but of the normative role they occupy in the subject’s perceptual economy at a time. Changing that role changes the verdict; holding it fixed does not.

In the scenario you describe, I agree that the eyes count as part of direct perception. And more generally, I’m happy to grant this: any system—organic or artificial—can count as constitutive of direct perception if it fixes the space of perceptual normativity for the subject at the time. What matters is not what the system is, nor which came first, but whether it defines what perceptual correctness even amounts to for that subject.

So if a subject initially has only the visor, then perception is direct relative to the visor. If the subject later acquires eyes that bypass the visor, then the eyes now constitute the perceptual capacity instead. In neither case is the constitutive system assessable as misrepresenting, because there is no independent perceptual standard against which its outputs could be evaluated. Altering or removing it would undermine perception itself, not merely change its outputs.

The contrast with the original visor cases is that there the visor operated against an already-defined perceptual capacity. That is what made misrepresentation intelligible. When a system intervenes on a perceptual capacity whose identity conditions are already fixed, its outputs become assessable as correct or incorrect relative to that background. That’s the sense in which the visor was instrumental in those cases and constitutive in the one you’ve now described.

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At this stage, I think it’s worth noting that once the distinction is understood in these role-relative, normative terms, it’s inevitable that there will be borderline and hybrid cases. I don’t see that as a defect in the view; it’s exactly what one should expect if perceptual normativity is not reducible to causal structure alone.

What the edge cases are really testing is not whether a particular gadget counts as “direct,” but whether there is any principled distinction between systems that establish perceptual standards and systems that merely operate within them. If one thinks that any lawful causal mapping to neural states fixes intentional content, then my distinction will inevitably look arbitrary. If one thinks that perceptual capacities fix standards of correctness that other systems can intervene on, then the distinction is principled even if it resists sharp boundaries.

So I’m happy to keep discussing cases, but I think we’re now very close to a foundational disagreement about normativity versus causal covariance—one that further edge cases will merely illustrate rather than resolve.

I apologize for the length of my replies. I don't feel I can do justice to your questions without going into detail.

No it doesn't. The visor doesn't purport to do anything. — Michael

I’m not attributing intentions, purposes, or design to the visor. “Purport” here is not a psychological or teleological notion. It doesn’t require anyone to think, intend, or even know that the visor exists. It marks a normative role a system plays relative to perceptual correctness, not an attitude the system has.

To say that a system’s outputs “purport to present the environment” just means this: the outputs are assessable as correct or incorrect relative to how things are, independently of whether the system is functioning normally or as designed. No intentions are required for that assessment to make sense.

That’s the crucial difference.

An organic visual system—even if it arose by chance, even if it were unknown to the subject—does not answer to an independent standard of perceptual correctness. If Jane’s eye maps 700nm light to a certain phenomenal character, that mapping fixes what red looks like for her. If the mapping were different, that would not make her perception false; it would make her a different perceiver. Biological malfunction is possible, but misrepresentation in the intentional sense is not separable from what it is for her to see at all.

By contrast, the visor’s mapping remains assessable as misrepresenting even if it arose spontaneously and even if no one knows it is there. We can coherently say: the visor is causing the subject to see the strawberry as blue even though, absent that device, it would appear red to that very same subject. That counterfactual comparison is what makes the visor’s outputs normatively assessable. No design, intention, or awareness is needed—only the fact that the visor intervenes on a perceptual capacity that is already defined independently of it.

So the distinction is not about what the visor “means to do,” but about whether a system defines perceptual correctness for a subject or is answerable to such correctness. “Purporting” names that answerability, not any inner purpose.

If you deny that distinction, then you are committed to the view that there is no principled difference between a system that constitutes perception and a system that merely alters its outputs—that all such systems are on a par as long as they are causally lawful. That is a coherent position, but it is precisely the internalist thesis at issue, not something forced on us by physics or by the absence of design.

So it's a question of whether perceptual normativity can be reduced entirely to causal covariance, or whether some causal systems fix the space of perceptual correctness while others operate within it. That’s the real fork in the road.

Why does a bionic eye "function as an intermediary whose output purports to represent the environment and can be assessed as succeeding or failing" but an organic eye doesn't? — Michael

It turns on what kind of standard a system is answerable to. I'll try to explain what I mean by this:

You’re right that Jane’s eye can be assessed against physical and biological standards. We can say that it malfunctions if it fails to transduce wavelengths in the statistically normal way, or relative to how human eyes typically function. But that kind of assessment is not yet an intentional standard of correctness. A biological malfunction is a failure relative to a kind; it is not, by itself, a failure to accurately present the world. Even a normally functioning eye does not answer to some prior specification of how the environment is supposed to look for Jane. Rather, it fixes what “getting it right” means for her perceptually. That is what makes it constitutive.

By contrast, the visor in (4) is assessable as misrepresenting the environment even when it is functioning exactly as designed. That difference matters. The visor’s outputs purport to stand in for how the environment is perceptually available independently of it, which is why it makes sense to ask whether those outputs succeed or fail as presentations of the world. That question does not arise for Jane’s eye, not because it is organic, but because there is no independent intentional standard against which its mapping could be evaluated for her. Its mapping is identity-fixing, not performance-assessable.

This also explains why lawful covariation and consistency are insufficient to erase the distinction. An organic eye with an inverted mapping is not misrepresenting the strawberry; it determines what it is for strawberries to look any way at all for that subject. A visor with an inverted mapping can misrepresent even while covarying perfectly, because its role is instrumental rather than constitutive. The possibility of misrepresentation without malfunction is exactly what marks that difference.

So the asymmetry is not asserted but grounded: Jane’s visual system constitutes her perceptual capacities because it defines the intentional space within which perceptual correctness is possible at all. The visor intervenes on an already defined perceptual capacity, which is why its outputs are assessable as accurate or inaccurate in a way the eye’s are not.

I think your question here makes the issue as sharp as it can be. I'll try to clarify where I think the equivalence argument ultimately breaks down.

I’m happy to grant that there is nothing privileged about proteins, and that a genuinely bionic eye could, in principle, count as part of a subject’s perceptual system. Material composition does no work here. What matters is not what the system is made of, but the role the system plays in constituting perception for the subject.

The distinction I’m relying on is not between lawful vs. unlawful mappings, or between covarying vs. non-covarying systems. I agree that in all of your cases—(1) through (4)—there can be lawful, consistent causal mappings from strawberry to neural outcome. So counterfactual covariation by itself cannot mark the difference. The real distinction is this: whether the mapping in question is constitutive of what it is for the subject to perceive at all, or whether it is a substitutable, instrumental mapping that could be altered without redefining perception for that subject.

In (2), Jane’s visual system—eye, retina, and downstream neural processing—constitutes her perceptual capacities. Whatever the mapping from wavelength to neural state happens to be (even under inversion), that mapping is not something that stands in for perception; it is how objects are perceptually available to her. There is no further question of whether this mapping is “doing its job correctly,” because it is not functioning as an intermediary whose output purports to represent the environment. It defines what counts as seeing for Jane.

By contrast, in (4), the visor introduces a mapping that is not constitutive in this sense. Even if it covaries lawfully with the strawberry, it functions as a substitutable system that fixes perceptual outcomes independently of the strawberry’s own role in determining how it is perceived. That mapping could be changed, replaced, recalibrated, or removed without thereby redefining what it is for John to perceive at all. That is why it is intelligible to ask whether the visor is presenting the environment correctly. The mapping is instrumental rather than constitutive, and so its outputs are assessable as succeeding or failing as presentations of the world.

This is also why (4) aligns with (3) rather than with (2), even though (4) bypasses the eye entirely. The difference is not whether an image is interposed, nor where in the causal chain neural stimulation occurs, but whether the system in question defines perceptual access or intervenes by imposing a detachable mapping. A bionic eye could fall on either side of this divide, depending on whether it becomes constitutive of the subject’s perceptual capacities or remains an instrument that determines perceptual outcomes in place of object-governed availability.

So the equivalence argument only goes through if one assumes that any lawful causal mapping to neural states is sufficient to fix intentional structure. That assumption collapses constitutive and substitutable mappings into the same category. I reject that assumption. Once the distinction is in view, it becomes clear why (1) and (2) count as direct perception, while (3) and (4) do not—not because of biology, reliability, or phenomenology, but because of the different roles these systems play in individuating what perception is for the subject.

I think the remaining disagreement comes from running together three different questions:

(1) how persistence through time should be understood,
(2) how causation across time works, and
(3) what “direct” is supposed to contrast with in a theory of perception.

First, about persistence. On Presentism, to say that the Sun persists through change is not to say that past parts of the Sun still exist. It is to say that the present Sun stands in lawful causal continuity with earlier states. Persistence here is not identity-with-the-past, but continuity governed by physical laws. Losing one atom does not generate a new object because nothing in our best physical theories treats that loss as a boundary for objecthood. The absence of a sharp cutoff does not show that persistence is merely linguistic; it shows that persistence is a real-world phenomenon that our concepts track imprecisely.

On a Block Universe view, the Sun is a temporally extended physical process. Different temporal parts are different physical states, but they are unified by belonging to the same continuous spacetime process governed by physical law. The relevant commonality is not qualitative sameness at each moment, but participation in a single causal–spatiotemporal structure.

Second, about causation. You repeatedly say that on Presentism the past “no longer exists” and therefore cannot directly affect the present. But this conflates existence now with having causal efficacy. On Presentism, causal explanations are perfectly coherent: present states are effects of earlier states, even though those earlier states no longer exist. That is not indirect causation; it is just causation across time. Likewise, on a Block Universe view, causal relations are encoded in the spacetime structure itself. Nothing needs to “move” between moments for there to be causal dependence.

Third, and most importantly, about perception. When I say that perception is direct, I am not claiming that the past is perceived as past, or that temporal mediation is eliminated. I am denying that perception proceeds by inference from an inner surrogate. On Presentism, my perception is directly related to a presently existing physical state through which the mind-external object is perceptually available (for example, light now arriving), where that state is itself the lawful causal manifestation of the object. On a Block Universe view, my perception is directly related to a temporal part of a mind-external process. In neither case is the direct object of perception a mental item that stands in need of inference to reach the world.

This is why the regress point still matters. If the mere fact that a causal chain involves time were enough to make perception indirect, then your own claim that perception is “directly of something that exists in my present” would not stop the regress. That present item would itself be temporally conditioned, causally structured, and conceptually articulated, and so—by the same standard—would require a further intermediary. To halt the regress, something must count as non-inferentially present to the mind, and temporal mediation alone cannot disqualify it from playing that role.

So the core issue is not whether only the present exists, or whether time is block-like. It is whether “direct” means non-inferential openness to mind-external reality, or instead absence of temporal structure altogether. I reject the latter requirement, and without it, the arguments you’re pressing don’t force the indirect realist conclusion.

I think your equivalence argument is very helpful, because it shows exactly where the disagreement lies. I’m happy to grant that (1) and (2) are on a par: variation in neural mapping or phenomenal character by itself does not make perception indirect. Where I part ways with you is in the move from (2) to (4), and therefore in the further identification of (4) with (3).

Your argument assumes that if two systems produce the same proximal neural outcome—e.g. stimulation of the B neuron—then they must have the same intentional structure, and so must count equally as cases of direct perception. That assumption is precisely what I reject. Intentional content is not fixed by proximal neural causes alone, but by the functional role of the system within a larger perceptual apparatus and its standing relations to the environment.

In (2), Jane’s eye and visual system are her means of perceiving the strawberry. The neural outcome is part of the perceptual process itself, not something she perceives instead of the strawberry. Differences in mapping (including inversion) affect how the strawberry appears, but they do not introduce a new object of awareness or a new question about whether what is presented corresponds to the environment. The system is functionally integrated into perception in such a way that the strawberry itself remains the intentional object.

In (4), by contrast, the visor is not functioning as part of the subject’s perceptual system in that sense. It is an external device that intervenes on the subject’s neural states, fixing the perceptual outcome independently of the normal perceptual linkage between subject and object. Even though there is no intervening “image,” the visor still determines what the perceptual state is of by inserting itself into the causal–functional role that normally belongs to the visual system. That is why (4) is relevantly like (3), not like (2): in both cases, the visor fixes the intentional object of experience rather than merely enabling access to it.

So the difference I’m drawing is not about where in the causal chain neural stimulation occurs, nor about whether phenomenal character matches across cases. It’s about whether the system producing the perceptual state is functioning as the subject’s means of perceiving the object, or as an intervening device whose outputs stand in for the environment. In (2), the eye is part of the perceptual system through which the strawberry is perceived. In (3) and (4), the visor plays a different functional role: it intervenes on perceptual states in a way that makes it intelligible to ask whether its outputs succeed or fail as presentations of the environment.

If one insists that intentional structure must collapse entirely into causal structure, then your equivalence argument goes through. But that insistence is a substantive internalist thesis, not something forced on us by physics or by the bare facts of causal mediation.

In what sense has your visor "failed" to present the strawberry to you? And why do we not ask if my eyes have "failed" to present the strawberry to me? — Michael

First I want to say that I agree that it would be a mistake to say that particular wavelengths or phenomenal characters “succeed” or “fail” as presentations of a strawberry. Neither wavelengths nor raw phenomenal character, taken in isolation, have correctness conditions. The notion of success or failure I’m invoking is role-based, not phenomenal: it concerns whether a system’s outputs function as presentations of the environment in a way that is answerable to how things are beyond the subject.

This is where the visor differs from ordinary vision, even allowing for spectrum inversion. In the inversion case, we can grant that you and I have systematically different mappings from wavelength to phenomenal character, and even that we enjoy the same phenomenal character when looking at the strawberry. Still, neither of us is perceiving an image that stands in for the environment. We are perceiving the strawberry itself, through our visual systems, under whatever lawful mapping holds for each of us. That lawful variation does not introduce a further question about whether what is presented corresponds to the environment; it just is how the environment is perceptually available to that subject.

The visor changes this structure. The crucial difference is not that the visor is physical while the eye is biological, or that one is reliable and the other not. It is that we do not perceive the outputs of retinal processing and then perceive the world by way of them; we perceive the world through the eye. By contrast, the visor produces an image that is itself an object of visual experience—something we see, and which purports to show us the scene beyond. Because the visor’s image is experienced as a presentation of the environment, it becomes intelligible to ask whether it corresponds to how things actually are. That is the sense in which its outputs can succeed or fail as presentations.

So the reason we do not ask whether your eyes have “failed” to present the strawberry is not that eyes are infallible, but that they do not introduce a detachable presentational layer whose outputs play the epistemic role of standing in for the world. The visor does. And that difference—between perceiving an object through a medium and perceiving an image that purports to present the object—is what introduces a normative dimension that causal covariance alone cannot supply.

Thanks for laying that out so clearly — I think this makes it obvious that we’re no longer talking past one another.

I agree with you on several points up front. I’m not trying to refute indirect realism, and I agree that IR can accommodate error, coordination, and action-guidance without collapsing into skepticism. I also agree that the epistemic situation is deeply underdetermined, and that “we can’t know with certainty” is a live philosophical outcome.

Before responding to your specific objections to experiential transparency, phenomenology of acquaintance, disjunctivism, and action-guidance, I want to flag why I haven’t engaged them directly. I’m not defending any of those positions. My claim is narrower: that the epistemic primacy of experience is itself a substantive theoretical commitment, not a neutral starting point. Whether or not disjunctivism or transparency succeed on their own terms is downstream of that more basic question.

Where I think we part company is over whether that underdetermination should be treated as a neutral default or as a philosophical choice. On the IR picture you’re defending, experience is effectively insulated from normative assessment: it can be causally aberrant, but it is not itself answerable to the world in a way that admits of correctness or incorrectness. Normativity enters only at the level of relations between experiences or theoretical overlays.

My move is to deny that insulation. I don’t think experience itself justifies our judgments, but neither do I think justification requires experiential comparison. The justificatory work is done by the norms governing world-directed judgment — norms shaped by, and answerable to, stable patterns of successful interaction with the world — with experience playing a causal, enabling role rather than an evidential one.

So I take your position to be coherent, but not compulsory. The disagreement, as I see it, is not about whether IR is viable, but about whether experience must be treated as epistemically primary in the first place.

I've been there myself, a long time ago. I agree with you: I was being chertitable. The post got some facts right, but it was wrong in all the ways that really matter. Take care.

Well, he at the least served as a poor example, showing us that the theory that there are two populations does not have a truth value. — Banno

Fair enough—I’m resisting the nudge to deny truth-value, but I’m happy to concede that Frank was a poor example either way. While I stop short of moving from “no epistemic role” to “no truth value,” the practical upshot is basically the same.

Good reply. — Banno

Cheers.

I think you’re right that we're hitting bedrock, but here are some additional thoughts for your consideration.

I’m not assuming direct realism in order to know that there is error. What I’m rejecting is the assumption — which I take to be doing a lot of work in the IR picture — that error must be identified by comparing experience with either a mind-independent phenomenal property or an inner experiential surrogate.

Returning to colourblindness: the basis for calling the judgment an error is not that the colourblind person’s experience fails to match mine, nor that it fails to match some phenomenal property instantiated by the object. The basis is that, within a shared practice of identifying and re-identifying objects across conditions, their judgments systematically fail to track features that figure in stable, publicly coordinated practices of correction and re-identification. That is an epistemic failure relative to those practices, not a phenomenal defect.

Importantly, this does not require assuming that colours are intrinsic properties of objects in a naïve realist sense. It only requires that our judgments are answerable to how things are in ways that admit of correction, stability, and disagreement. The colourblind person’s experience is not “wrong”; the experience is simply different. What can be wrong is the world-directed judgment, assessed within that normative context.

On the IR picture you gesture at, where there is no genuine error in perception outside of hallucination, I would say that this is not a neutral starting point but already a substantive philosophical commitment — one that insulates experience from normative assessment altogether, treating it as epistemically foundational rather than answerable to anything beyond itself. My move is to deny that insulation. It's not a leap so much as a refusal to grant that experience must be epistemically primary in the first place.

So the disagreement isn’t really about colourblindness as such. It’s about whether we think the notion of error belongs fundamentally to experience, or to the judgments we make about the world from within perceptual practices. I’m firmly in the latter camp.

You, EQV, just refuse to commit. :wink: — Banno

Poor Frank leaves the lab more confused than when he came in, but that's OK — he wasn't doing any philosophical work for us, and probably won’t be invited back. :wink:

I didn't say that it's about neural states. I'm saying that phenomenal experience is neural states (or emerges from them). — Michael

Thanks, that clarification helps, and I agree with more of what you say than perhaps my earlier wording suggested. I also do not claim that perceptual content is about neural states, nor that distal objects or their properties are literally present in neural activity. I also agree that there is no “real appearance” transmitted through space and into the brain. Where I think we still disagree is about whether causal covariance exhausts the intentional structure of perceptual states.

On your view, phenomenal character is self-standing, and the relation to distal objects is entirely causal. Given that, I agree that the visor looks continuous with ordinary perception: in both cases there is a neural state with a certain phenomenal character, caused in some way by the world. But that continuity is purchased by treating accuracy as non-fundamental—as a pragmatic gloss rather than a constitutive feature of perceptual content. If one is happy with that consequence, then that is a coherent internalist position; it is simply not one I accept.

I don’t think accuracy talk is optional in that sense. In the visor case, it matters whether the image on the screen corresponds to how things are in the environment, not because a “real appearance” is being compared to a copy, but because the perceptual state purports to present the environment itself—that is, it has correctness conditions that are not exhausted by its phenomenal character or causal history. The difference between an accurate visor and a misleading one is therefore not exhausted by differences in phenomenal character; it is a difference in how the state is answerable to the world.

This is why I don’t think the visor is just another causal conduit like light or reflection. Ordinary causal media do not introduce a layer whose outputs can succeed or fail as presentations of the environment. A visor does. Its outputs stand in normative relations to what is going on beyond the subject, even if the subject is unaware of the visor’s existence. That normative dimension is exactly what causal covariance alone cannot supply.

So the disagreement isn’t about whether appearances are transmitted, or whether phenomenal character is neural. It’s about whether perceptual states are merely causally covariant with the world, or whether they are constitutively world-answerable. If one denies the latter, then I agree the visor case collapses into ordinary perception—but only because one has already accepted a thoroughgoing internalism on which accuracy is not fundamental. That is the position I’m resisting.