No, I'm saying that it's thing directly seen. From this we then make judgements about the world that can be correct or not. — Michael

I see what you're saying, but I think that the distinction you're making here is more terminological than substantive. As I understand your account, it requires that it is possible for there to be a mismatch between the phenomenal character of experience and the world. Understanding phenomenal experience as something that can succeed or fail to line up with how things are burdens it with a representational role that I would reject. That's a difference in how we locate epistemic mediation within the context of perception, not about whether judgments are made “from” experience,

Yes, I think this makes the divergence fully explicit now.

You’re treating phenomenal character as that which is assessed for correctness in the act of perception, whereas I’m treating judgments about the world as what are assessed, with phenomenal character merely causally occasioning those judgments.

The difference here concerns what we each take as epistemically basic. It may be that we've hit rock bottom on this issue, which is fine. Either way, I have enjoyed the discussion very much.

I think this is where we finally reach the deepest point of disagreement.

I reject the assumption that for veridical perception and hallucination to belong to a “common kind,” there must be a common object that is the immediate object of assessment. On my view, what is common is not an object, but a kind of epistemic activity: world-directed judgment undertaken from a perceptual standpoint.

In veridical perception, that judgment is answerable to objects in the environment and can be corrected by further interaction with them. In hallucination, the same kind of judgment is made, but it fails—there is no object that satisfies it. No inner surrogate is thereby promoted to the status of what is assessed; rather, the judgment is simply false.

That is why the Common Kind Claim does not force the conclusion you draw. Fallibility does not require that the immediate object of assessment be the same in success and failure. It requires only that the same kind of claim can succeed or fail.

This is also why the bionic vs organic distinction does no work here. I agree entirely that proteins are not privileged over silicon, and that both are deterministic transducers. But that shows only that causal mediation is ubiquitous. It does not show that perception involves an epistemic intermediary unless one assumes that error must always be explained by reference to an inner object.

So the dilemma you pose—either perception is indirect in both cases or direct in both cases—rests on an assumption I reject: that epistemic assessment must target an intermediary whenever perception can misfire. I deny that assumption. Judgments can be directly answerable to the world and still be wrong.

@Metaphysician Undercover @Magnus Anderson

It seems to me that this discussion keeps looping because the objection is being framed as an internal refutation of standard mathematical proofs, rather than as a foundational challenge to the notion of existence those proofs rely on.

Both of you have raised worries about the “doability” of bijection for infinite collections, which suggests a rejection of the identification of existence with formal definability and consistency. That’s a substantive philosophical position. But if that’s the objection, then it isn’t a matter of showing that the usual definitions lead to contradictions (they don’t), but of rejecting the underlying framework.

Put differently, the objection seems clearer if stated explicitly at the level of foundations, e.g.:

“I reject the identification of mathematical existence with formal definability. I require a constructive or modal account of possibility, and under that account I deny that completed infinite bijections exist.”

or

“I reject classical set theory in favor of a finitist or constructivist framework, where existence requires explicit construction.”

Framed that way, the disagreement would look less like an accusation about the failure of proof and more like a clash of foundational commitments, which is where I suspect the disagreement really belongs.

So why is this not also the case for the bionic eye? It simply replaces rod and cone cells with silicon. — Michael

It could be the case for a bionic eye — nothing I’ve said rules that out.

Simply replacing rods and cones with silicon does not by itself introduce an epistemic intermediary. What matters is not what the components are made of, but whether the system functions as part of the ordinary perceptual coupling with the world, or instead produces an output whose correctness must be assessed independently of that coupling.

If the bionic eye is integrated into perception such that judgments are still answerable to objects through ongoing interaction and correction — as with natural, transplanted, or lab-grown eyes — then there is no epistemic intermediary, and perception is direct in the sense I’m using.

The visor and nerve-stimulation cases differ because they interpose a surrogate whose adequacy depends on a generating process that stands in for the world, rather than being part of the perceptual relation itself.

So the distinction isn’t silicon vs biology, or artificial vs natural; it’s whether the device replaces part of the perceptual interface with the world, or replaces the world with an internal stand-in.

I agree entirely that judgment and reasoning depend on sensation in the sense you’re emphasizing. Without sensory experience, there would be nothing to judge about, and no reasoning could get started at all. I’m not denying that causal or developmental dependence.

The distinction I’m drawing is about epistemic role, not dependence. Sensations are conditions for the possibility of judgment, but they are not themselves reasons, premises, or justifications. That is why judgments, but not sensations, belong in the space of reasons. A sensation can prompt, occasion, or constrain a judgment, but it is the judgment that takes responsibility for saying how things are and can therefore be assessed as correct or incorrect.

So when I say that sensation does not “enter into” justification or inference, I don’t mean that judgments could exist without sensation. I mean that sensation does not function as a truth-apt item alongside judgments. The dependence you’re pointing to is real, but it doesn’t undermine the distinction I’m trying to mark.

The SDR says that they are directly cognizing the ship in the mind-external world, but if in the mind of the SDR there is no direct cognition of a weight of 10,000 tonnes, length of 200m, width of 25m and height of 30m, then what exactly is the SDR directly cognizing? The idea of a ship? — RussellA

I think what’s really at issue here is how we understand truth and directness. On my view, truth doesn’t consist in a resemblance or mirroring between what’s in the mind and what’s in the world, but in a judgment’s being correct or incorrect depending on how things are. That doesn’t require the ship’s properties to be present in the mind, only that the judgment be about the ship itself. Perception is direct in that sense: the object of perception is the mind-external ship, even though only some of its properties are perceptually available at any given time. Whether a judgment about the ship is true is settled by how the ship is, not by how closely something in the mind matches it. I realize this may sound like I’m simply assuming that judgments can be answerable to the world, but every account of truth has to take something as basic; here the difference is just whether one starts from mirroring relations or from the idea that judgments aim at getting things right about the world.

I would say that there is no relevant difference of the kind you are asking for — because the distinction I’m drawing is not about the material or biological status of the causal chain at all — but about the epistemic role it plays.

In ordinary perception — regardless of whether the eye is natural, transplanted, or artificially grown — one’s judgments are answerable to objects in a shared environment through ongoing interaction and correction, not to an internal signal whose adequacy must itself be evaluated.

I would say that the change doesn’t affect the point I was making.

Moving the interface from a screen to direct stimulation of the optic nerve changes the location of the causal mediation, not its epistemic role. In both cases, what the subject’s judgments are immediately answerable to is a generated input whose correctness depends on how it was produced, rather than to the objects themselves. That is the sense in which the perception is indirect.

I agree that humans ought to be continually making judgements …
Is not the normal use of the word “normative” a moral norm, such as “you ought not smoke”? — RussellA

Yes — in ordinary language, “normative” is often used for moral norms. But that is not the sense in play here.

By epistemic normativity I do not mean “humans ought to be continually making judgments.” I mean something closer to this: when we make judgments, we are implicitly adopting standards of correctness (e.g. truth, evidence, coherence, reasonableness).

In other words, judgment is normative because it is answerable to how things are. To judge at all is to commit oneself to being right or wrong, and to being accountable to reasons. That commitment is built into the act of judging; it is not a further moral obligation one may or may not take on. To reject those norms is not to judge differently, but to stop judging altogether.

And while these norms are indeed socially mediated, I would argue they are ultimately grounded in the subjectivity of the individual.

Surely, if we are looking to an authority, we would prefer an authority that cannot be wrong, such as the senses, rather than an authority that is more often than not wrong, such as a judgement. — RussellA

Here the contrast is misleading. Sensation is not “an authority that cannot be wrong”; it is not an authority at all, because it is not the kind of thing that can be right or wrong. To say that sensation is not truth-apt is to say it can be neither correct nor incorrect.

Judgments, by contrast, can be wrong — but that is precisely because they are the only things that can also be right. Error is not a defect relative to sensation; it is the price of intelligibility. Only what can be mistaken can be corrected, justified, or improved. That is why judgments — not sensations — belong in the space of reasons.

The problem is we give no authority to a judgement just because it is a judgement. We give authority to the content of a judgement. — RussellA

I think this shows that the word “authority” is doing more harm than good here, and that may be my fault for introducing it.

All I mean by saying that judgments have epistemic authority is that they are the locus of truth and falsity. Sensory qualities — redness-as-seen, pain-as-felt — are not the kinds of things to which truth or falsity apply at all. Judgments are. That is the only contrast I am trying to mark.

So the point is not that judgments are authoritative regardless of content, nor that every judgment deserves equal credibility. It is that only judgments, whatever their content, are even candidates for being assessed as correct or incorrect. Sensation constrains judgment, but it does not itself enter into justification or inference.

Compare this with words. "Dog" represents dogs. Yet, the word "dog" in itself, is not correct or incorrect. It simply is what it is. But, when placed in a larger context, for instance, pointing to an animal, and uttering "dog", then the word can correctly indicate the animal pointed to, or not. — hypericin

I would say that words are essentially representational: to be a word is to be a bearer of meaning or reference. And while I agree that context is required in order to fix a word’s conditions of use and meaning, context does not transform a word from a non-representational kind of thing to a representational one.

Smells are not like that. They can causally indicate ammonia, just as smoke can indicate fire, but the correctness conditions do not attach to the smell itself. They attach to the judgment made on the basis of it. When smell is misleading (hallucination, long covid, etc.), we don’t assess the smell as incorrect; we assess the judgment as mistaken or the sensory capacity as unreliable.

So even in context, phenomenal qualities are not what represents the world. They are a causal-enabling condition under which world-directed judgments acquire correctness conditions. That is the sense in which I deny epistemic mediation while fully granting causal mediation.

Hmm, this is not how I experience odor. The smell itself is what hits me first, viscerally and immediately. No introspection is needed. If the smell is a familiar one, I might identify it quickly, so quickly that it might even seem immediate. But if I haven't smelled that smell in a long time, it can take significant mental effort to identify it. Occasionally, I won't be able to at all, and I am left frustrated, wondering what that smell reminds me of.

Do you not relate to this? — hypericin

I relate to that description completely. But I think this brings out a distinction rather than a disagreement.

What you’re describing is immediate phenomenal awareness — the smell hitting you viscerally, prior to identification. I don’t deny that at all. What I’m denying is that this involves an introspective judgment in the epistemic sense.

An introspective judgment would be something like “I am having a sharp, acrid olfactory experience.” That’s a reflective, truth-apt claim about one’s experience. In ordinary cases, we don’t make that judgment first. We either make a world-directed judgment (“that’s ammonia,” “something smells off”), or we hesitate from making a judgment at all because we can’t yet place it.

I would say that the delay or effort you describe doesn’t show that we infer from an inner premise; it shows that perceptual judgment can be difficult, uncertain, or fail altogether. Phenomenal awareness can be immediate without functioning as an epistemic intermediary.

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To sum up: it seems like the divergence between us can be captured by a single question: are phenomenal qualities representational vehicles whose correctness conditions are fixed in context, or are they non-representational causal conditions under which world-directed judgments acquire correctness conditions.

What do you think?

Cheers. Enjoy the weather.

I largely agree with the position you've been defending on this thread. The only significant divergence we have is the one we've discussed on another thread. Whereas you would say:

But our understanding is always, and already, an interpretation, so the "flower-as-it-really-is" or the "flower-in-itself" is already a nonsense. — Banno

I would say: "our understanding is always, and already an interpretation, and the notion of the 'flower-as-it-really-is' or the 'flower-in-itself' is a non-eliminable regulative ideal around which the act of inquiry itself is organized".

Another divergence is that I am perhaps more apt to treat talk of phenomenal experience as legitimate (though not epistemically foundational).

Outside of those two things, I don't find much to disagree with in what you say.

Thanks for clarifying!

Here is how I would approach each of the three propositions. I’ll try to reuse your examples so that we can better observe how our approaches differ.

(1) Phenomenal qualities represent aspects of the world.

False. The sharp, pungent, acrid scent of ammonia as-smelled does not, in itself, represent anything in the world. Neither does redness as-seen, loudness as-heard, or sour as-tasted. A representation is something that can be assessed for correctness, truth or fidelity. Raw sensory qualities are not the kinds of things that can be correct or incorrect; they simply are what they are.

(2) Ordinary perceptual judgments are judgments about phenomenal qualities.

False. Ordinary perceptual judgments are about things in the world (“that rag smells of ammonia”), not phenomenal qualities (“there’s a sharp, pungent, acrid scent in my olfactory map”). The former are typically referred to as “perception”, the latter as “introspection”. Introspection is second-order, reflective and derivative with respect to ordinary perception.

(3) Our knowledge of the world is inferred from such (introspective) judgments.

False. We do not ordinarily infer perceptual judgments from introspective judgments. Rather, perceptual judgments are epistemically primary, and introspective judgments are appealed to only in reflective, corrective, or explanatory contexts. And even then, introspective judgments are typically not used to justify perceptual judgments, but only to help reason about (or explain) anomalous cases (e.g. uncertainty, disagreement, illusion).

As you can see, we approach and answer these questions in significantly different ways. What do you think of this?

I don’t dispute either of the points you raise. Yes, we experience phenomenal character, and yes, the looks, sounds, smells, and feels involved in perception are properties of the nervous system. I also wouldn’t deny that perceptual judgment is causally mediated by phenomenal character.

But the issue isn’t causal mediation; it’s epistemic mediation. Consider the following commitments:

(1) Phenomenal qualities represent aspects of the world.

(2) Ordinary perceptual judgments are judgments about phenomenal qualities.

(3) Our knowledge of the world is inferred from such perceptual judgments.

One influential way of understanding epistemic mediation in the indirect realist tradition involves accepting commitments like these. I reject all three. For that reason, I reject the claim that perceptual judgment is epistemically mediated in the traditional sense. That’s also why I think the photograph analogy misleads: it tacitly presupposes at least one of these commitments, whereas my view denies them.

Out of curiosity, which of three propositions above would accept, if any? Does the distinction between causal and epistemic mediation as laid out above make sense to you, or would you qualify it in some way? I’d be interested to get your thoughts.

Thanks for contributing to the discussion with a thoughtful reply. I thought I would chime in since this overlaps with so many of the same issues I've been discussing with @Michael and @RussellA.

The photograph case you raised is an interesting test case because I think that it subtly presupposes exactly what is at issue. The photograph itself is what is perceptually present, and the person is not. That’s why it’s natural to say the person is only perceived indirectly. But in ordinary perception there isn’t an analogous surrogate object that stands in for the ship in that way; at least, that is the point at issue. The ship itself is what our judgments are about, and it's what also constrains our beliefs over time.

That’s why I’m hesitant to say that the “primitives of perception are hallucinations of the brain.” That description already assumes that phenomenal character functions like a photograph—i.e. as the thing perceived instead of the object—whereas both @Banno’s point (if I'm understanding him correctly) and my own have been that phenomenal character causally constrains perception without being its direct object.

I agree that rejecting naïve realism is mandatory, and that causal mediation alone doesn’t settle the issue. But I don’t think the photograph case shows that perception must be indirect in the sense of being mediated by inner surrogates rather than being answerable to the world itself.

I think there’s a subtle but important shift in your reply that ends up missing the point I was making.

My claim was not that single judgments are reliable, infallible, or likely to be correct. Epistemic authority is not a matter of probability, reliability over isolated cases, or confidence in one-off judgments. It concerns what kind of act is even eligible to be assessed as correct or incorrect at all.

Sensation, as you agree, is not truth-apt. Judgments are. That difference is not about likelihood of error; it is about logical role. Only truth-apt acts can be wrong, and only what can be wrong can be corrected, justified, or criticized. That is the sense in which epistemic authority “resides” in judgment rather than sensation.

So when you say that neither a single sensory experience nor a single judgment has epistemic authority, I agree — if “authority” is taken to mean certainty or high probability. But that is not the sense at issue. The point is that only judgment participates in the space of reasons at all, even when judgments are tentative, revisable, or likely to be false.

Likewise, the normativity I’m invoking is not the moral norm “you ought to judge,” nor the psychological commitment to judging. It is the epistemic normativity built into judgment itself: judgments answer to how things are, can succeed or fail, and can be revised in light of further reasons. Sensory experience constrains this process, but it does not enter it as a premise.

So I don’t think we need to “look elsewhere” for epistemic authority. We just need to distinguish authority from certainty, and normativity from reliability. Epistemic authority lies in judgment because judgment alone is answerable to truth — even when, and especially when, it turns out to be wrong.

Yes — that’s a good way of putting it, and I agree. I didn’t mean to suggest bijection is foreign to finite counting, only that when we move to infinity the remainder-based cues we rely on in finite cases stop being reliable, even though the underlying correspondence idea remains.

This is where I think a crucial distinction is getting lost.

The normativity I’m talking about is not a property of the content judged, but of the act of judging. The proposition “if I see orange, then the screen is orange” is entirely descriptive. What is normative is taking it to be true — committing oneself to its correctness and taking responsibility if it turns out to be false.

That’s why comparisons with laws or moral rules don’t quite apply. Legal and moral norms are prescriptive and externally grounded. Epistemic normativity is neither enforced nor derived; it is imminent and constitutive. To judge at all is to place oneself under standards of truth, justification, and error. No additional rule, institution, or innate principle is required.

So when I say judgment is normative, I don’t mean that it issues an “ought” in the moral sense, or that it is governed by conventions. I mean that to judge is to take a stance that can succeed or fail — that can be correct or incorrect — and that this answerability is what distinguishes judgment from mere sensation or description.

That is also why sensory experience, while indispensable, cannot itself function as an inferential premise. Sensation is not the kind of thing that can be right or wrong. Judgment is. And that difference is where epistemic authority resides.

Thanks for laying this out so clearly. Unfortunately, I think a couple of confusions have arisen regarding my position. Let me try to clarify.

First, when I speak of normativity, I am not talking about moral norms (e.g. “evil is bad”), but epistemic normativity: truth, falsity, correctness, and justification. To make a judgment is to take on a set of epistemic responsibilities. That normativity is constitutive of judgment, not something inferred from experience or imposed by the will, and it is independent of any moral “ought”.

Second, I don’t think the rationalism/empiricism contrast maps cleanly onto the disagreement between us. I’m not claiming substantive knowledge of the world independent of experience, as classical rationalists did. But neither am I claiming that experience supplies inferential premises from which all other knowledge is derived, as classical empiricists did. What I reject is empiricist foundationalism: the idea that non-conceptual sensory states can function as epistemic grounds or premises.

On my view, experience is indispensable, but it does not do epistemic work by representing or grounding inference. It constrains judgment non-inferentially, by situating inquiry and correcting it, while judgment alone bears epistemic authority. That places my position outside the traditional rationalist/empiricist divide rather than on the rationalist side of it. My position is best described as post-Kantian with a contemporary anaytic twist, and is heavily indebted to thinkers like Peirce, Sellars and McDowell.

This is why the “direction of fit” framing doesn’t quite apply. I’m not saying the mind legislates how the world must be, nor that sensation ought to match reality. Sensation itself is non-normative. The act of judgment is intrinsically normative, not because it is independent of experience, but because it is truth-apt.

So in the orange-screen case: I’m not saying that because there is an orange screen I ought to see orange, nor that seeing orange licenses an inference. Rather, when I judge “the screen is orange,” that judgment is assessable for truth, and experience constrains it without functioning as a premise.

That, I think, is where our views genuinely diverge: whether sensory mediation itself does epistemic work by representing and grounding inference, or whether judgment alone is epistemically authoritative while experience constrains it non-inferentially.

I think this helps clarify where we diverge. You’re treating “number of elements” as a notion whose inferential rules must be fixed by finite counting, and on that assumption the infinite case does look contradictory. Mathematics takes a different route: it treats counting as the finite implementation of a more general notion of size, and allows the implementation to change when counting no longer applies. I think has done a fine job of showing the inconsistencies that arise if we don't.

That’s why defining a bijection counts as establishing existence in this context, and why reindexing in Hilbert’s Hotel isn’t seen as pretence. At that point the disagreement isn’t about technique, but about whether such revisions are legitimate at all.

I see what you’re getting at, and I agree that bijection strictly extends our ability to reason about size — especially once infinities are in play. In that sense it’s an enrichment, not a rival notion.

The small point I was gesturing at is that, while the bijection criterion agrees with the remainder-based notion on all finite cases, it does so by no longer treating “having a proper remainder” as decisive for size comparison. That inferential role is preserved extensionally for finite sets, but it no longer has the same explanatory force once we move to the infinite case.

So I’m not suggesting that anything correct is lost in the finite domain — only that some intuitive cues we rely on there stop doing the work we expect of them when the concept is refined for a broader domain.

Cheers. I largely agree with you that formal language is not something alien to natural language, but a tightening of it — making explicit commitments and inferential roles that are often left implicit in ordinary use.

Where I’d add a small nuance is that the act of tightening isn’t always neutral. In refining a concept, we sometimes preserve certain inferential roles while deliberately abandoning others that no longer serve the new domain. In the case of “size”, the move to formal language preserves comparability and transitivity for infinite collections, but it does so by dropping the remainder-based role that functions perfectly well in the finite case.

So I don’t see formal language as distinct from natural language so much as selectively continuous with it: a refinement that’s purpose-driven rather than a mere sharpening of everything we already mean.

I agree that this is now a question about how the debate has been traditionally framed, not about skepticism or justification.

I don’t deny that many historical direct realists tied direct perception to naïve colour primitivism, nor that Locke-style views are the canonical contrast class. In that sense, my view is revisionary with respect to the traditional dialectic.

What I reject is the claim that phenomenal mirroring is constitutive of directness rather than a substantive thesis adopted by particular direct realists. The falsity of naïve colour primitivism shows that the world is not phenomenally as it appears, but it does not by itself show that perception must proceed via inner representations standing in for the world.

When I say that perception relates us directly to mind-independent objects, I do not mean that any causal or informational link counts as direct. The visor case is instructive precisely because it introduces an epistemic intermediary whose outputs are the immediate objects of assessment. By contrast, in ordinary perception, our judgments are answerable to objects themselves within a shared public environment, not to internal surrogates whose accuracy must be inferred.

So the disagreement isn’t about whether my usage matches a traditional definition — I’m happy to grant that it doesn’t. It’s about whether we should inherit phenomenal mirroring as a constraint on realism about perception at all. That is the assumption I’ve been rejecting throughout.

Point taken. I agree that once infinite collections are treated as completed totalities, the intuitive, remainder-based concept of size becomes inconsistent, and your examples make that very clear. I don’t think the intuitive concept is incoherent as such — it’s well-behaved in the finite case — but I agree that Magnus’s attempt to generalize it to infinite collections fails.

Your reply nicely clarifies the remaining disagreement.

You say the minor “premise” “I am seeing orange” is not truth-apt but can still function in an inference. I don’t think that position is stable. Inference is a normative relation between propositions, and only truth-apt contents can play that role. If “I am seeing orange” is not truth-apt, then it is not a premise at all, and the conclusion cannot be inferred from it.

This is why I distinguish constraint from grounding. Sensory contents constrain inquiry by occasioning and shaping judgment, but they do not function as inferential grounds alongside judgments. The epistemic work is done entirely at the level of judgment.

This also bears on representation. To say that “the orange I see in my mind represents the screen being orange in the world” reintroduces normativity at the level of sensation. Representation can succeed or fail, and once sensation represents, it is no longer non-normative. That is precisely the move I’m resisting.

Finally, rejecting empiricist derivations of norms does not imply Idealism. Epistemic norms are conditions for the possibility of inquiry, not constituents of reality. To say that judgment is norm-governed independently of experience is not to say the world is mental, but that knowing has irreducible normative structure.

So the disagreement is not about whether the senses mediate our contact with the world — I agree they do — but about whether that mediation itself does epistemic work by representing and grounding inference, or whether judgment alone bears epistemic authority while experience constrains it non-inferentially. That is where we part ways.

Thanks — that clarifies your position.

I don’t deny that many historical formulations of direct realism build in the conditional you cite: if perception is direct, then the world is phenomenally as it appears. Nor do I deny that naïve colour primitivism is false.

What I reject is treating that conditional as definitive of direct perception rather than as a substantive thesis adopted by particular theorists. The falsity of naïve colour primitivism shows that the world is not phenomenally structured as it appears, but that conclusion is neutral on whether perception relates us directly to mind-independent objects or only via inner intermediaries.

Your argument depends on defining direct perception in terms of phenomenal mirroring. My resistance has been to that definition. As I’m using the term, directness concerns whether perceptual judgment is answerable to the world itself, not whether phenomenal character reproduces the qualitative character of reality.

So I don’t dispute your historical reconstruction or the science. I’m disputing whether we should inherit that conditional as a constraint on how the problem must be framed.

I agree that everything I described — coherence, responsiveness to further experience, success in inquiry — could in principle occur in a hallucination or brains-in-a-vat scenario.

But I don’t think that concession supports the conclusion you want to draw.

The mere possibility of global deception does not by itself show that perception is indirect, nor that the world is not as it appears. It only shows that perceptual judgment is fallible — something I have never denied.

The step I think you’re taking for granted is this: that if perception were direct, then massive and systematic error would be impossible. But I don’t see why that should be accepted. Directness is a claim about the kind of relation perception bears to the world, not a claim about epistemic guarantees or immunity to skepticism.

In other words, the fact that we could be wrong about everything does not entail that our beliefs are mediated by representations standing in for the world, rather than being judgments answerable to the world itself. Fallibility and answerability are compatible.

That’s why I don’t take brains-in-a-vat scenarios to motivate indirect realism. They motivate epistemic humility, not a particular metaphysics of perception. To get from “global error is possible” to “perception is indirect” you need an additional premise — that direct perception would rule out such error — and that premise is exactly what I reject.

So the disagreement here isn’t about whether skeptical scenarios are conceivable. It’s about whether conceivability alone licenses conclusions about the structure of perception. I don’t think it does.

This is helpful, because now the skeptical pressure you’re worried about is fully explicit.

I think the crucial step where we diverge is here: you’re assuming that for an ordinary perceptual belief like “there is a ship” to be justified, I must also be justified in believing something like “my current experience is not hallucinatory” — i.e. that I must first justify a claim about how my experience relates to reality before I’m entitled to make any claims about the world.

I reject that requirement.

It helps to distinguish carefully between phenomenal character itself and claims about how things appear. Phenomenal character is not truth-apt; it does not assert anything, and so it is not something that can be correct or incorrect. Claims about how things appear (e.g. “it looks orange to me”) are truth-apt, but they are reflective, second-order claims that arise for special purposes — disagreement, error-checking, theory-building — not as the epistemic basis of ordinary perceptual judgment.

Ordinary perceptual beliefs are not justified by first establishing that one’s experience is veridical rather than hallucinatory. In normal cases, one does not infer “there is a ship” from the premise “it appears that there is a ship.” One simply judges that there is a ship, and that judgment is assessed over time by its coherence with other judgments, its responsiveness to further experience, and its success or failure in inquiry.

This is why the indistinguishability of hallucination and so-called “veridical” experience does not generate skepticism on my view. That skeptical pressure only arises if we assume that perceptual justification requires antecedent justification of claims about how things appear. I deny that assumption.

Hallucinations matter epistemically when they function as defeaters within inquiry, not as a standing possibility that must be ruled out in advance in order for any perceptual belief to be justified at all.

So the disagreement isn’t about whether hallucinations are possible or whether phenomenal character can be misleading. It’s about whether justification for ordinary beliefs about the world depends on first justifying claims about appearance. That is the assumption I’ve been challenging throughout.

Perhaps, but then by "perceptual belief" I mean "a belief that the world is as it appears". — Michael

Thanks for making the definition explicit — that helps a lot.

I don’t accept that a perceptual belief should be defined as “the belief that the world is as it appears.” That definition already builds in the very thesis at issue in the direct/indirect realism debate, namely that phenomenal appearance is the standard against which perceptual belief is assessed.

By perceptual belief I mean something more ordinary and less theory-laden: they are beliefs about objects and states-of-affairs that are formed in ordinary perceptual contexts (e.g. “there is a ship”, “the screen is emitting orange light”, “the umbrella is wet”). Whether the world is “as it appears” is a further philosophical question about how such beliefs relate to phenomenal character, not what makes them perceptual beliefs in the first place.

Once that distinction is in view, my position is straightforward: perceptual beliefs can be justified even if phenomenal character does not mirror the qualitative character of the world. Justification does not turn on the world being “as it appears,” but on norm-governed judgment answerable to how things actually are, with experience constraining inquiry rather than supplying a standard of adequacy.

If one defines perceptual belief by stipulation as belief that the world is as it appears, then of course my view won’t count as addressing that debate. But that would mean the disagreement is about how to frame the problem, not about whether perceptual knowledge is possible.

Thanks, this helps clarify where the disconnect is.

I think the issue is that your formulation of (1) already presupposes a particular conception of justification — namely, that perceptual beliefs are justified if and only if the world is “as it appears”, where phenomenal character is taken to mirror the phenomenal character of the world (as in naïve colour primitivism).

That is precisely the assumption I’m rejecting. I don’t think perceptual justification turns on whether phenomenal character is the phenomenal character of the world, either successfully (direct realism) or unsuccessfully (indirect realism).

So I don’t agree with the indirect realist that perceptual beliefs are unjustified, nor do I agree with the direct realist about why they are justified. On my view, perceptual beliefs are justified by norm-governed judgment answerable to how things are, with experience constraining inquiry but not serving as the justificatory ground.

In that sense, I’m not denying perceptual justification; I’m rejecting phenomenal appearance as the criterion of it. That’s why my position doesn’t line up cleanly with either side of the traditional direct/indirect realism divide as you’ve framed it.

Thanks — this is very helpful, because it makes the structure of your view explicit.

I think the disagreement now turns on a single point. You want stage-two contents (“I am seeing orange”) to be conceptual but not truth-apt, and yet to function in inference to stage-three judgments (“the screen is orange”). But inference requires propositional, truth-apt premises.

That leaves you with a dilemma:

• If “I am seeing orange” is truth-apt, then it is already a judgment and your staged model collapses.
• If it is not truth-apt, then it cannot function as a premise, and the claim that stage-three judgments are inferred from it does not follow.

This is why I’ve insisted that perceptual judgments are not inferred from sensory contents. Sensory experience constrains inquiry causally and motivationally, but it does not supply inferential premises.

When you say that “seeing orange represents an orange screen,” you are reintroducing representation at the sensory level — precisely the move I’m resisting. On my view, representation, truth, and epistemic authority belong at the level of judgment, not sensation.

So the issue isn’t whether the senses mediate our contact with the world — I agree they do — but whether that mediation is inferential and representational, or whether judgment is norm-governed and answerable to how things are without being derived from inner items. That is the point at which we diverge.

I think the recurring confusion here comes from a difference in what we take the core epistemological problem to be.

As you frame it, the dispute between direct and indirect realism concerns whether phenomenal character presents mind-independent properties, and whether skepticism follows if it does not. Within that framework, I agree that rejecting phenomenal presentation pushes one toward indirect realism.

My claim is that both traditional direct and indirect realism share a deeper assumption: that phenomenal character is epistemically primary, and that justification for beliefs about the world must flow from experience outward (whether successfully or unsuccessfully).

I reject that assumption. On my view, phenomenal character neither succeeds nor fails at justifying knowledge of the world; it is not the kind of thing that plays that role at all. Epistemic justification belongs to judgment governed by norms of relevance, sufficiency, and answerability to how things are, not to phenomenal character.

That’s why my position doesn’t fit cleanly into the traditional direct/indirect realism framework. I’m not trying to resolve that dispute on its own terms; I’m questioning whether it’s framed at the right epistemological level to begin with. So the divergence is genuine, but it's aimed at a shared underlying assumption rather than at one side or the other within the traditional framing.

I agree that propositions like “I am experiencing such-and-such phenomenal character” are truth-apt and can function as premises in reflective reasoning. My claim was never that such inferences are impossible.

What I deny is that ordinary perceptual judgments are epistemically justified by inference from such introspective premises. In normal perception, John does not first judge “I am experiencing orange” and then infer “the screen is orange”; he simply judges that the screen is orange. Introspective propositions typically arise later, and for special purposes (disagreement, error-checking, theory-building).

Your reconstruction helps explain how John and Jane might reason about their perceptual differences, but it does not show that perceptual judgment itself is grounded in inference from introspective awareness. Those introspective premises are reflective and ad hoc with respect to perception, not epistemically basic.

So while P2 can play an explanatory role in some contexts, it does not follow that perceptual knowledge of the world is generally inferred from it.

I agree that background knowledge plays an essential role, and I also agree that differences in phenomenal experience help explain why different hypotheses are entertained or dismissed. Where I still disagree is in treating phenomenal character itself as an inferential input.

Even given background knowledge, phenomenal character is not truth-apt and cannot function as a premise. It does not count for or against a hypothesis in the way evidence does. Rather, it causally constrains inquiry by making certain hypotheses intelligible or salient and others not.

The inferential work is done entirely at the level of judgment, under norms of relevance and sufficiency, drawing on background knowledge and further perceptual judgments. Phenomenal character helps explain why those judgments arise, but it does not justify them or serve as a premise from which they are inferred.

So I don’t deny that phenomenal experience matters in inquiry; I deny that it plays the epistemic role you’re assigning to it.

I think part of what’s driving the disagreement here is that two different notions of “same size as” are in play, and they come apart precisely in the infinite case.

In everyday contexts, “same size” usually means something like this: if you subtract one collection from another and anything is left over, then they are not the same size. That notion is closely tied to finite counting, monotonicity, and the idea that proper subsets must be smaller than wholes. By that standard, it’s perfectly reasonable to say (for instance) that the natural numbers and the integers are not the same size.

What @Banno is appealing to, though, is a different notion that mathematicians use when working with infinite sets: sameness of size defined in terms of one-to-one correspondence. On that definition, “same size” no longer tracks what’s left over after subtraction, but whether elements can be paired without remainder. This isn’t meant to preserve ordinary quantitative intuitions; it’s meant to give a notion of comparability that still works once subtraction and counting break down.

So I don’t think the disagreement here has to be read as one side being confused or irrational. It looks more like a clash between two legitimate concepts that happen to share the same words. The intuitive notion works well for finite collections but doesn’t generalize cleanly; the mathematical notion is explicitly engineered to handle infinite cases, even at the cost of violating everyday expectations.

Once that distinction is on the table, the question isn’t really “who is right,” but what we want the concept of “same size” to do in this context. Mathematics answers that one way; ordinary language answers it another.

Thanks for laying this out so carefully — this helps clarify exactly where we disagree.

I want to focus on the role you assign to your stage two, since that’s where the inferential claim is doing all of its work.

You characterize stage two (“I am seeing orange”) as conceptual but not truth-apt, and therefore not a judgment. I’m happy to grant that description for the sake of argument. But then I don’t see how stage two can function as the basis of an inference to stage three. Inference requires premises that are truth-apt — something that can be correct or incorrect. If stage two is not truth-apt, it cannot play that role.

So either stage two is truth-apt, in which case it already is a judgment and your staged model collapses, or it is not truth-apt, in which case the claim that stage-three judgments are inferred from it does not follow.

More generally, I don’t deny that all inquiry is mediated by the senses. What I deny is that mediation entails inferential grounding. Sensory experience supplies data that constrains inquiry, but it does not supply premises from which judgments about the world are inferred. The epistemic work is done at the level of judgment itself, not by moving outward from inner representations.

For that reason, rejecting inferential mediation does not amount to Idealism. It does not deny a mind-external world, nor does it deny sensory mediation. It denies only the empiricist assumption that knowledge of the world must be constructed by inference from sensory contents.

So the disagreement isn’t about whether the “bridge of the senses” must be crossed — it’s about what crossing that bridge amounts to: inferential reconstruction from inner items, or norm-governed judgment constrained by experience but not inferentially derived from it.

Between the mind and any external world are the five senses. The mind only knows what passes through these five senses. Therefore, for the Indirect Realist, anything we think we know about any external world comes indirectly from “inference to the best explanation”. However, for the Direct Realist, we are able to transcend these five senses and directly know about any external world.

One question for believers in SDR is how they explain their judgements are able to transcend their phenomenal experiences — RussellA

I can only speak for myself on this, but I do not reject the idea that knowledge is mediated by the senses. What I reject is the idea that sensory content forms an epistemic base from which the rest of our knowledge about the world is inferred.

The key issue here is that sensation is not a normative act. This means it is not conceptual and is not truth-apt – it is simply not the kind of thing from which the rest of our knowledge could be inferred.

By contrast, judgment is conceptual and truth-apt. The act of judgment is part of the norm-governed process of inquiry. So, while judgments are constrained by sensory content, they are not inferred from sensory content. As we argued above, this would be impossible.

When we make perceptual judgments we are not making judgments about sensory content. We are making judgments about things in the world (“there is a ship”). That’s not to say that we can’t make judgments about sensory content – we can (“I am seeing red”) – but this is not what we ordinarily mean by the word “perception”. Instead, this is a reflexive, second-order kind of judgment more commonly referred to as “introspection”.

I would argue that perceptual judgments are neither inferred from nor justified by introspective judgments. If someone questions one of our perceptual judgments, we don’t try to justify it by appealing to introspective judgments. Instead, we appeal to background knowledge and other perceptual judgments.

Consider the example of John and Jane that provided. Jane makes a perceptual judgment (“the screen is orange”) and infers that the wavelength of the light is between 590nm and 620nm. Appealing to an introspective judgment (“I am seeing orange”) in order to justify her perceptual judgment simply won’t convince anyone, including herself. If she really wants to justify her judgment that the screen is orange, she’ll need to appeal to her background knowledge (optics, screens, color-blindness, etc.) and further perceptual judgments about her environment (current lighting, viewing angle, screen filters, etc.).

So when you ask how judgments are able to “transcend” phenomenal experience, my answer is that they can’t – at least not in the sense of bypassing or overriding the senses, nor by inference from inner representations. Rather, judgments were never justified by phenomenal experience to begin with. Sensory experience constrsins inquiry by supplying data, but epistemic authority belongs to judgment, which is governed by norms of sufficiency, relevance, and answerability to how things actually are. Once that distinction is in view, the need to “bridge” phenomenal experience via IBE largely dissolves.

I'm not so sure about this. While God is not seen as an efficient cause of entities, it is seen as their final cause, IIRC. Given this, I'm not sure how you can safely say that their intelligibility isn't rooted in the Unmoved Mover according to him. — boundless

That’s a fair point — you’re right that, for Aristotle, the Unmoved Mover functions as a final cause of cosmic motion, even though it is not an efficient cause. I don’t mean to deny that.

My claim is narrower: even granting divine final causality, Aristotle does not treat the Unmoved Mover as the source of the intelligible form of natural substances. Final causality explains why motion is directed toward an end; form explains what a thing is, and it is form that grounds intelligibility. On Aristotle’s own terms, those forms are intrinsic to substances rather than conferred by divine cognition.

So while Aristotle certainly affirms a divine intellect, the intelligibility of nature, as he understands it, does not consist in being thought by God, but in being formally structured in its own right. And on that much, I think we agree that intelligibility alone doesn’t prove the existence of God.

Note that Aristotle himself, however, endorsed the idea that a Divine Mind exists. I know that one can make an Aristotelian model without reference to such an Intellect, but it nevertheless is interesting that apparently Aristotle himself thought that the two ideas are connected. — boundless

That’s true, although it’s worth noting that Aristotle’s unmoved mover does not function as a source of the world’s intelligibility. As νοήσεως νόησις, it thinks only itself, and does not impose form or order on the cosmos. For Aristotle, the intelligibility of nature is intrinsic to substances themselves rather than conferred by a divine intellect contemplating or structuring the world.