I agree with all of this, and I think it’s a good account of how the process works. My nagging question is, in a way, terminological, but it may be important when we remember that the word/meaning example was originally given as an analogy to the harder question about how rational/mental meanings can supervene on physical systems tout court. Let me try to restate it, and perhaps in doing so I’ll find the answer!

The letter G, on my understanding, is not a (merely) physical item. To be seen as “the letter G”, to be recognized as such, is also to apprehend its meaning. One reason we know this is true is that infinitely many versions of the letter may be written – physical alterations, in other words – without altering our ability to recognize it as the letter G.

So we can’t use the letter G as the subvenient term in a supervenience relation between the strictly physical and the strictly mental. The letter G is already a hybrid, it already requires mental content, or meaning (or whatever term is least controversial) in order to be paired with what supervenes upon it.

Now there’s no rule that says that the only kind of supervenience is between the strictly physical and the strictly mental. But that is the most common use of the term, and I think it’s the one we should be concerned about here. Again, remember that we want to wind up with a better understanding of the OP question about the two kinds of causation, re the dominoes. I agree with @Wayfarer that these correspond to efficient and formal cause, but this merely shows us that the problem is a very old one. “Formal cause” is a sort of blank check, and we need to cash it out in a way that doesn’t turn it into just another physical cause in fancy dress.

So maybe the question about the letter G becomes: If there were a strictly physical subvenient item somewhere in the neighborhood, where would we look for it? On my view, it has to be “beneath” or “prior to” the letter G itself, which is already a physical/meaning hybrid.

"Change" is applied to the meaning of (written) words insofar as the letters change, not insofar as the serifs change. — Leontiskos

Right, that’s what we want to say. But is this really a supervenience on strictly physical reality? Let’s back up: What makes a letter the key unit of significance, and thus one of the physical items upon which the meaning of a word may supervene? What happens between the serif and the letter, as it were? This is all presumably a matter of convention, but we still must ask, At what point does the meaning get injected? I can say “ArchG [that is, the archetypal letter G upon which various calligraphical variations may be built] is, in English, the 7th letter of the alphabet” and say similar things about H’s position, and I’s, etc. That’s what the physical item means, or symbolizes, along with, perhaps, some pronunciation rules.

But what’s the difference, what happened, between, say, an upside-down G, which means nothing, and good old G? How does the “correct” physical organization produce meaning? Don’t we want to say that the meaning comes from somewhere else entirely, namely whatever group of humans have contrived this alphabet? (Or, as you put it, “a mind is infusing material reality with meaning.”) So by the time we arrive at the level of “the meaning of a word supervening on letter-changes,” we’re already working with a dual description, i.e., G as physical item, and G as symbol. Therefore (finally!): Can this really be supervenience between the physical and the mental, if G is already being used as a meaning vehicle? What is the (allegedly) strictly physical description of the subvenient set?

These are real questions on my part. I’m not sure about any of it.

I would want to say that the rational/mental meaning supervenes on the purely physical system, in much the same way that the meaning of a word supervenes on the written symbols or spoken phonemes. — Leontiskos

Interesting. I think the problem here is that a written symbol or a spoken phoneme already has meaning built into it, in your sense. Consider the written symbol, strictly as a physical object. If I remove a serif from one of the letters, this ought to change something in the meaning of the word, on strict supervenience. It doesn’t, of course, because we don’t really begin from the physical objects when we consider the word/meaning relation; we’ve already been taught how a letter of the alphabet works, and why there can be infinitely many permutations of calligraphy that don’t affect meaning.

Not to say that supervenience is dead wrong here. Could you work up an example that preserves the basic “if A changes, then B changes” idea of supervenience as applied to symbols and meanings?

I agree, it's a good question, but I think we need to sharpen it, as follows:

"What caused the last domino to fall?"

This prevents at least some of the "resolution by ambiguity" responses we'd be tempted to make (different levels of "why" questions, etc.). The reason the question is interesting -- and hard to answer -- is because it's asking if some kind of mental or "rational" causality is even possible. You can't get to a putative "dual explanation" until you first take a position on this kind of causality, and whether chains of physical causality can ever be grounded in the mental.

Your reply reveals an unintended ambiguity in what I wrote. By talking about consciousness as an "exclusively biological phenomenon" I was meaning to contrast that view with another current hypothesis, that nonbiological entities like computers might also be conscious. But you quite plausibly took this in a different direction: whether a "biological" -- in the sense of physical or scientific -- understanding of consciousness would necessarily be reductionist, leaving no room for what you call "add-on" features like imagination or, in my examples, rationality.

Pretending to be a scientist for a moment, my hunch is that consciousness will indeed prove to be an exclusively biological phenomenon, in the sense I originally meant. But that would have no bearing on whether the subjective products of consciousness have the objective or universal qualities that Nagel and others believe they do. That's why I think it remains a philosophical rather than a scientific question.

What do you see as the overriding and outstanding issues of the philosophy of mind in the twentieth first century? Is there any essential debate beyond the scope of psychology? — Jack Cummins

Getting back to your original question: I’d rather answer it as if you’d asked, “What should be the outstanding issues?” I’m sure @Wayfarer and others may be right in describing the current dominance of reductive physicalism within academia, but fashions change.

The most important scientific questions should focus on trying to learn what consciousness is – whether it’s a biological phenomenon exclusively, and whether some Copernican revolution will emerge in our understanding of how the mental and the physical are lawfully connected. Fascinating as this is, it’s not for philosophers to weigh in on.

Rather, I think the “essential debate” for us hasn’t changed much. It was, and is, “How can the subjective processes and procedures of consciousness produce things like ‛ideas,’ ‛concepts,’ ‛meanings,’ ‛truths’? How can these interior, 1st-person-point-of-view results be given a description that does justice to what they seem to demonstrate – namely, that reasons are not caused, and are not causes, in the same way that physical processes are?” I reveal my biases here, of course. Many would argue that the questions are absurd, as nothing of the kind actually happens. But for those of us who think that reasons do provide justifications and, often, objective truths, our problem is to explain what we mean by this, and how it could be possible in what seems to be a causally closed physical world, a world that, in theory at least, should be completely explainable in its own terms, without recourse to esoterica like “mental content”.

The best philosopher I know on this subject is Thomas Nagel. Both The Last Word and The View from Nowhere lay out the case for why we can’t reductively explain, e.g., logic and mathematics without running up against paradox and contradiction.

Clear and helpful, thank you.

It certainly isn't a confirmed fact that any Gospel was written before any other. — Count Timothy von Icarus

I hold no brief for Ehrman or any other particular Biblical scholar, but surely this is taking skepticism about history too far. What counts as a "confirmed fact" is debatable, of course, but I don't know of any scholar or historian who seriously doubts (and provides some evidence for their view) that Mark was the first Gospel. If you do, could you share that? I'd be grateful.

Good citations, thanks. If I have a beef, it's clearly with Witt and not your interpretation of him!

I'm not sure that isomorphism is the right word, as it suggests that they are independent of each other.

Thought and language are two aspects of the same thing. A proposition is a thought and a thought is a proposition. — RussellA

I'm no Tractatus expert, but I don't think this is right -- wouldn't it be more Witt's position in the Phil. Investigations, rather than here? Leaving aside the perhaps trivial point that we can have thoughts that are non-propositional, we should take more seriously Witt's use of "picture" at so many critical points in the Tractatus. I don't read him as suggesting that language is the only picture-making tool at our disposal.

With that said, though, I agree that it's hard to fit in the "limits of language" quote. But I'm not the first to suggest that the Tractatus, for all its careful organization, is often self-contradictory.

So what would be the point of needing what you cannot have? — Arne

And no philosopher worth their salt is going to allow anyone to decide what they mean by the terms they use. It is not going to happen. — Arne

The tragic view of philosophy! Quite possibly the correct one -- we will never get what we need, but, like Sisyphus, we can't stop pushing the philosophical rock up the hill.

If you want to read a first-rate philosopher discuss all these issues, try Reality+, David Chalmers' new book. It sheds light on a lot of what's being debated here.

I was getting at a different question about causality -- not whether the lamp causes the perception (in sense-1) of the lamp, but whether the supervenience relation is also causal. To put it another way, you use the phrase "experience can arise" to describe what happens when we go from a physical brain state to a mental state; my question was whether this arising is a causal relation. I think you can have supervenience without causation.

But now we're definitely off-topic, so I'll just say thanks for the response!

Very clear and helpful. If we can say that Hegel's view was pretty close to the idea that "reality" doesn't mean "whatever's 'out there' apart from phenomena," then I'm content. It may not even be necessary to uphold a modified correspondence theory, which has all the problems you point out (and my attempt to rephrase it was totally clumsy!).

For what it's worth, I've always respected Susan Haack's theory of “foundherentism,” an unfortunate term for very interesting idea that tries to make a bridge between foundationalism (or realism, in this context), and coherentism. I can’t do her justice here, but her inspiration is American pragmatism, and she quotes James approvingly: “When we give up the doctrine of objective certitude, we do not thereby give up the quest or hope of truth itself.”

This exchange has motivated me to reread her Evidence and Inquiry to see if she considers her foundherentism to be a correspondence theory; I no longer remember.

Good, that's what I hoped you would say. The "direction of fit" question is important, and we don't want the two senses of "perception" to escape very far from each other's orbit. But would you agree that "supervenience" is not "causality," and that the story we tell about how sense-1 and sense-2 perceptions connect doesn't have to be a causal one?

Like you, I apologize to others on this thread if I'm veering too far off topic. Just want to give this one point a closer look.

John Searle argues that many of the great modern philosophers use perceptual verbs ambiguously in two different senses.

1. In a constitutive sense. The perception is understood as what is constitutive for having it, such as brain events or a perceptual process that exists only for the one who has the perception.

2. In an intentionalistic sense, The perception is understood as what is perceived, or what the perception is about. For example, the visual perception of the lamp. — jkop

Not to take sides on Searle's contributions to philosophy overall, but this distinction is extremely useful, I think. You mention that this ambiguity allows us to stipulate perception in sense 1 but not sense 2 (hallucinating the lamp, or "seeing a lamp that isn't there"). But does it also support the reverse? That is, can I maintain that my sense-2 perception of the lamp is genuine, and a legitimate use of the word "perception," without committing myself to some story about how it supervenes (or otherwise connects) to a sense-1 perception?

Your translations from Hegelese are excellent, thank you! And the bolded paragraph from the Encyc. Brit. does seem very close to the question at issue in the OP.

The Hegelian position here is that “one can’t step outside belief altogether.” “Every search must end with some belief” about the results of the search. For Hegelians, this situation is an important and somewhat scandalous insight. For various versions of realism, it’s unsurprising and unproblematic.

Why would we expect “stepping outside belief” to be the criterion for knowing something about reality? What about the distinction between belief and justified true belief? A modest realism only asks that there be this difference, and that our epistemological search can end with JTB, rather than mere opinion. (JTB is not certainty, except possibly for analytic propositions, and that’s why I call it a modest realism.) The opposing idea would seem to be that only an unmediated, “unbelieved” Reality with a capital R could be the proper goal of the search. Or perhaps the idea is that, unless we can make contact with such a reality, we’re in no position to judge whether a belief is a JTB.

Would such contact be the same thing as contacting what is “given” to the mind, “direct apprehension,” “unmediated knowledge,” etc., on this view? I suppose so, since it can be plausibly argued that we never do achieve such contact. But I don’t see why the realist needs to concede this equivalence between “direct apprehension” and reality. They can say instead that a phrase like “the experience of reality is always mediated by beliefs” is either incoherent – there is nothing to be experienced – or that it’s perhaps true of “givens” or “raw feels” or some such, but that this is not what we mean by reality. The correspondence we’re looking for is not between propositions and “unmediated” reality, but rather between certain beliefs about states of affairs, and whether those beliefs are warranted.

Having said all this, I think the issue may be a classic instance of a kind of “spade-turning” difference in intuition about metaphysics. I don’t expect a Hegelian to be swayed by what I’m saying, and they probably don’t expect me to be swayed either. Each of us thinks the other is arguing in a circle, in some important sense, or missing a basic insight about the possibilities of experience. Philosophy goes on, precisely because we don’t really know what to say about these bedrock differences . . .

OK, I think I understand you. You're saying that the "assumption" is not about a specific P being true prior to verification, but rather about truth in general being knowable and recognizable as such. Or if not truth in general, then truths of the sort that can (putatively) be verified by simple perceptual experiences such as seeing a cat, coupled with some basic background information. This procedure would reveal "truth-makers," if all goes well.

How is a state of affairs outside of the logical grid of language and logic possible to affirm since any affirmation itself is weighed within that very grid? — Astrophel

I don't understand this question re truth-makers. What does it mean for an affirmation to be "weighed"? Do you mean "judged true or false"? If so, one can only reply that there is a distinction between states of affairs, which would exist without any perceiver, and the statements we make about them, including judgments of truth and falsity. I suppose that is an assumption, if you like. We don't have to use the word "true" (or "false") at all if we really don't believe there are such things as statements that correspond (or don't) to reality in a Tarskian T-truth sort of way. And yes, it's very vexing that no account of how this works seems flawless. But to affirm P, and to have a justification for doing so, doesn't make P disappear into a vicious circle of linguistic/logical assumptions, unless you're a severe sort of Idealist . . . which is maybe what @Count Timothy von Icarus is getting at, above, with his Hegelian analysis.

This has been fun to watch from the sidelines. I more or less share Banno’s point of view on this, but I have a feeling some basic clarification might help. For starters:

And the great flaw in the traditional analysis of knowledge has always been the assumption that P is true, that is, "S knows P iff S believes P, is justified in believing P and P is true" has no business simply assuming "P is true" without itself having justification, and this too would require justification, and it never ends. — Astrophel

Perhaps the problem here is that we’re not understanding what you mean by “simply assuming ‛P is true’”. As I read JTB, no such assumption is made. The truth of P needs to be independently verified, yes, but by using the term “justification” for this (presumably perceptual or scientific) process, we get unnecessary confusion, as if the whole thing were somehow circular. But, as has been pointed out, truth-makers aren’t usually the same things as justifications. Truth-makers are states of affairs, not propositions. JTB states a hypothesis: If P is true, and S has justification for this belief that P, then S knows P. So, could you clarify where the “assumption” comes in?

I don't read Rawls as saying that definitions of the good have to be unanalyzable preferences. This seems to set up a false binary: Either the good for individuals can be known and agreed upon by some rational, objective process (and presumably form the basis for a civil society), or else all we're left with is "unanalyzable preferences." Rather, what we're left with is what we see in more-or-less democratic, more-or-less civil societies -- vigorous dispute over what is good! Dispute and lack of resolution do not necessarily indicate that a problem is "unanalyzable," only that it's difficult and perhaps evolves historically. In addition, we can allow that progress is possible, as indeed has happened in Western democracies, I believe.

If a society based on Rawls principles is set up, and over time it evolves into ABNW, where is the objection supposed to come from? — Count Timothy von Icarus

You! That's the whole idea -- a pluralism of viewpoint is encouraged. See something wrong? Speak up, make your argument. Unless the suggestion is that ABNW would somehow rob people of their ability to notice what's dangerous within their society? It's been years since I read the novel, and perhaps Huxley does suggest this, in order to make his world truly dystopian, but I think that's unrealistic. Remember, the ideal liberal democracy thrives on disagreement, not conformity.

This is a scary vision, all right. I don’t think it has much to do with Rawls or political liberalism, though. It’s a huge subject, obviously, so let me just raise two points.

1) Yes, Rawls is offering a theory of political virtue, not individual morality. He’s not agnostic or skeptical about morality, as one person or another may conceive it; he himself was surely a hard-core Kantian. What he argues for is a hands-off approach by liberal governments when it comes to what is sometimes called “legislating morality.” He assumes both pluralism and tolerance. “Messing with the system that makes most other people happy,” to use your phrase, would presumably involve active restraints or disincentives on certain behaviors, as government policy. And Rawlsian liberals believe this is not the right approach, that tolerance of stupidity and wickedness is, in the end, the lesser of two evils. I emphasize again that this whole theory applies to social structures, not individuals. Personally I despise all forms of bigoted rhetoric, for instance, and do everything I can to oppose it; I’m not the least bit personally tolerant in this area. But I don’t want my government to censor or ban it. I’m also against a life of selfish pleasure, but liberalism asks me to tolerate in my role as citizen your choice of lifestyle even though I disapprove.

2) I think Rawls had much higher hopes for a society that implemented his theory of justice – higher, that is, than a sort of pleasure-based accommodation of desires. It isn’t only personal desires that thrive in a liberal democracy. So too do ideas, values, commitments, imagination, and deeply experienced “projects” of all kinds. And so does impassioned disagreement. Rawls believed we would become better people in a just society, not all at once, but as a result of participating in a fair political process. And his vision of “better” is surely not a matter of binges and entertainment. I guess another way of saying it is: Rawlsian liberal democracy is our best shot at creating a society that allows you or me the unfettered opportunity to argue for our personal morality, and perhaps see those arguments prevail.

That's a resounding note to end on, but I'm impelled to add: Rawls did not pay nearly enough attention to systemic economic inequality and its effect on fairness.

the dialogue between then Cardinal Ratzinger and Jürgen Habermas — Wayfarer

Habermas is exactly who I was thinking of as an exponent of this ongoing, rational, consensus-driven approach to knowledge and values!

Intersubjective agreement is essential when it comes to scientific hypotheses, but it's not realistic when it comes to one's own existence, unless you're part of a collective. — Wayfarer

This is complicated, but I understand what you mean. We don't want our values determined for us by consensus. But the alternative of stubbornly asserting one's own right to decide what matters based on nothing other than personal choice is surely a version of the inimical individualism you've been writing about. As usual, we're looking for reasonable middle grounds for compromise . . .

What I'm referring to is the centrality of individualism to liberalism and modernity, and the individual as the sole arbiter of value in Enlightenment philosophy. I would have thought that an uncontroversial claim. The underlying point is that with the rejection of the transcendent, we are inhabitants of Max Weber's 'disenchanted world'. — Wayfarer

OK, the world may be "disenchanted" in Weber's sense, but surely "the individual as the sole arbiter of value" isn't the only remaining alternative. Isn't there an vigorous, important strain of thought in the West that tries to find meaning and value in various forms of community, intersubjectivity, etc.? I'd argue that, in fact, this is the basis of scientific method and of Deweyan pragmatism; no single individual can assert what is valuable or not; reasoned, fallible consensus is required.

Yes, what you say about Simpson's criticism is similar to the points that Nussbaum and others have made. There is a claim to a sort of obviousness in Rawls' initial intuitions about what needs to be "veiled" in order for justice as fairness to emerge. Why these intuitions and not others? As for cultural relativism, I don't know what Rawls may have said about it to Hare or anyone else, but to me it's plain from reading A Theory of Justice and Political Liberalism that Rawls was trying to craft a conception of justice that was in some important ways transcultural for democracies. I'm not sure if Rawls ever gave an argument as to why an autocracy, for instance, could in principle not be just. He was concerned with finding a firm basis for liberal democratic values as he understood them, and also (to quote his opening statements in Political Liberalism), "to develop an alternative systematic account of justice that is superior to utilitarianism." This shows his basic Kantian commitments, I think.

BTW, the only thing I thought was unfair about Count T's reference to Rawls was this: "We might try to imagine ourselves 'behind the veil of ignorance,' but we can't actually place ourselves there." I took this to mean that the thought experiment couldn't succeed, because we can't actually become ignorant in the right ways, and that Rawls was somehow overlooking this. But this may not have been Count T's meaning.

why does the abstract rational agent want the society they want? — Count Timothy von Icarus

We should probably start a different thread to pursue this. But I think you're right that the liberal/Kantian ethical position begins by refusing to specify morality ("what should I want?") and instead assumes that a just society will make maximal allowance for many ethical points of view and prudential goals. This, then, at a higher level, is "what I should want" -- a contractarian respect for something that looks like the categorical imperative with a dash of tolerance added. And the (perhaps interminable!) debate is about what that maximal allowance should be. Free speech? Sure. Free speech that directly threatens me with death? Surely not. Free speech that promulgates morally obnoxious points of view, according to me? Not so clear . . . European liberal democracy often says no, US Constitution usually says yes. And the conversation goes on.

Rawls might be another example. In grounding social morality in the desired of the abstract "rational agent," debates become interminable. We might try to imagine ourselves "behind the viel of ignorance," but we can't actually place ourselves there. — Count Timothy von Icarus

I'm not a Rawlsian all down the line, but I do think you're being unfair here. The veil of ignorance, or the "original position," is a technical contrivance Rawls uses to set a basis for his very complicated discussion. He's well aware that no one actually starts from there, any more than we formally adopt "the social contract." If you want to read some good objections to the original position from a sympathetic philosopher, read Martha Nussbaum's Frontiers of Justice. Her basic criticism is that the conditions Rawls asks us to be ignorant of -- race, class, sex, a particular conception of the good -- may not include some other equally important ones, such as disability or even species.

That was a bit off topic, but my next comment is relevant, I think. You say "debates become interminable" if social morality is based on the prudential desires of abstract rational agents. But one person's "interminable debate" may be another's "ongoing process of communication and refinement of values." It raises the question, Why do we expect rational debate to terminate? Are there in fact instances of this, in philosophy? Might not one of the virtues of rationality be its (perhaps) endless willingness to continue the conversation? When I deny misology and put my trust in reason, I'm also declaring my faith in certain human characteristics and values -- patience, fairness, inclusion, intellectual honesty. Is this model of reason in fact Eurocentric, or patriarchal, or similarly flawed by historicity? That may well be -- but the only way find out is to keep talking about it.

In liberal political theory, the individual conscience is the sole arbiter of value. — Wayfarer

Hmm, I'm wondering who you have in mind here. If we take John Rawls as a paradigm liberal political philosopher, we certainly don't find him making such claims for conscience, as far as I can tell. Also, we shouldn't oppose duties of conscience to Catholic teaching. Looking at my old adult catechism, I find, from the Second Vatican Council, "Every one of us is bound to obey his conscience." Aquinas evidently agreed, writing that a person is obliged to follow their conscience even when, unknown to them, it is quite mistaken -- "to deny one's conscience is to turn one's back, if not consciously on God Himself, at least on moral authenticity," according to the catechism.

The question is then, How is one's conscience formed? And of course the catechetical Catholic answer will be very different from, say, the existentialists. "The sole arbiter of value," even for Sartre, doesn't come from conscience, but rather from a series of choices which then inform conscience. These choices may be arbitrary or absurd, but if so, it isn't conscience which will tell us so. We need reasoned discussion for that. Or perhaps a Catholic would add -- "and appeal to authority."

:lol:

If the activity is no longer "philosophy", what is it? — Paine

Right, that would be the question. PI 194 turns out to be a good test case, because the description
LW gives of philosophers -- "we are like savages, primitive people, who hear the way in which civilized people talk, put a false interpretation on it, and then draw the oddest conclusions from this" -- surely can't be self-referential; that is, refer to the very statement LW is making. (Presumably he doesn't think he has drawn any odd conclusions from misunderstanding "civilized" people.) Rather, it's a critique of what some philosophy leads to -- but critique in the name of what?

Maybe you could say more about the implication that philosophy has been abandoned. — Paine

Here I'm just referencing the usual idea that LW's program was "therapy," an attempt to get us to stop engaging in certain fruitless lines of thought and speech. Maybe "murder-suicide" would be more accurate! Can you end philosophy, using philosophy? For my part, I prefer to take LW's brilliant speculations at face value, for what they add to our understanding of rationality and language, and not worry too much about whether he was right that 1) philosophy ought to be/can be abandoned and 2) LW himself has stopped doing it, as of . . . right now . . . . or no, wait, he means at the end of this sentence . . . no, wait . . . . OK, now he's stopped . . .

Do you know of an instance of Habermas bringing the charge of performative contradiction against Wittgenstein? — Paine

I don’t. If anything, Habermas seems sympathetic to the later Wittgenstein (less so to the Tractatus). But there’s a lot I don’t know about Habermas.

“Performative contradiction”: I suppose it depends on how seriously you take the idea that LW was not doing philosophy in, e.g., the PI. The passage you quote begins “When we do philosophy . . .” and the meaning of the sentence implies that LW himself, in this “performance,” isn’t doing philosophy, but rather commenting on it or criticizing it. Is this really tenable?

. . . and a general reply to this conversation: In his excellent book The Logic of Reflection, Julian Roberts reads LW as asserting in the Tractatus that “the structures of truth and certainty are only very inadequately rendered in natural language,” quoting 4.0002: “Language disguises the thought.” But by the time of the Remarks on the Foundation of Mathematics, “Wittgenstein questioned whether there was any such thing as a ‛fact’ independent of the system we used to describe it. Arithmetic, for example, taught us to see particular sorts of ‛fact’.” So language, and the various language-games, would trump logic or structure.

I think LW is open to the charge of what Habermas calls “performative contradiction,” in that he seems to be privileging a particular language-game in his later writing to discuss, criticize, and relativize language-games. It doesn’t matter whether we call this game “philosophy” or not. The question rather is whether such a critical perspective carries its own warrant, so to speak, or whether it is merely another way (among many) of seeing “particular sorts of ‛facts’.”

↪Jamal That makes sense to me -- The purposes of philosophy differ between them. — Moliere

Makes sense to me as well, though I think there is indeed a parallel, which you've pointed out.

Very interesting. Do you think the later Wittgenstein was in sympathy with the idea that reason can be self-reflective, or at any rate can reflect critically upon the forms of understanding? I’m not sure how to read Wittgenstein on this. In the Tractatus, I think LW is saying that such a critical project would be just "metaphysics". But can a “form of life” include a more generous scope for philosophical language that abstracts from experience (or "my world") to question itself?

So, this version of the P-Region has the same sort of multiple realizability that B-Minimal properties do, but at the cost of becoming virtually the same thing. — Count Timothy von Icarus

Yes, this is helpful. I agree.

The way I understand it, we are talking about the actual spatio-temporal region involved in producing M given any one actual instance of M. — Count Timothy von Icarus

This seems to be key. Is an "actual" S-T region one that can only change in certain ways? What I mean is, adding to and subtracting from the mass of P-Reg(P) is doable, in our world. It's a manipulation we can perform on the same region, or at least that's how it seems sensible to think about it. But can we change the physical composition of the substance, without replacing the "actual" example with a different one -- one of the "physical ensembles"? In short, are changes in composition allowed in theory, or does the idea of an "actual" S-T region automatically shut down any such theoretical manipulations?

I think this question makes sense, but we may be losing sight of why multiple realizability matters in the first place. What we want is an explanation of supervenience that preserves a kind of rough-and-ready causality (no M without P) but doesn't commit us to a S-T causality that is unique, that can only happen once. Any sphere will have the property of roundness. The roundness of SphereA isn't caused in space and time -- you don't start with the sphere at T1 and then get the roundness at T2 -- yet it is a property that supervenes on a specified physical (or mathematical, if you prefer) arrangement. So it ought to be multiply realizable. And then the question gets interesting if we go on to ask, "Are minds and brains like this? Is consciousness a property of the brain? Does that mean that a given thought is multiply realizable? How about an entire mind?" etc.

I figured. Just wanted to make sure I understood you, thanks!

Agreed. The skeptical position is almost always about the limits of knowledge, not a declaration about what does or doesn't exist. And it tends to equate knowledge with certainty, as you say -- a much easier target for doubt.

One thing I'd add: You say we might agree with the skeptic that

(b) proof and absolute certainty are chimeras in epistemology — Jamal

but aren't they only chimeras in reference to the external/empirical world? I think you can be a Humean skeptic while reserving a place for genuine analytic knowledge. For Hume, relations of ideas, which would include math and its proofs, are not problematic, because they can be known by reason alone, requiring no reliance on experience.

Love it! Can we see his picture? Well, not "his" picture, if by that you mean Noumenal Former Fred . . .

Of course the Kantian analysis can be played for laughs. The question, if we want to be serious, remains whether some kind of intersubjective agreement is a sensible way of describing human "objective" knowledge.

OK, I thought you were referring to brain states (P) giving rise to mental states (M). The P ("exterior" object) to M (perception of it) is different, I think. For the latter case, it's trivially true that all the Ps have to be unique, if there is more than one perception. (This is assuming that P must include a temporal dimension.). And we could generously allow that the M states are identical across perceptions, though this is by no means certain. But how does this bear on the multiple-realizability question? Is there even such a question with regard to this kind of example? We could talk about "multiple realizability" of perceptions of an apple, but this won't tell us what we want to know about the relationship between physical brain states and the mental events.

Perhaps, to make the two kinds of examples clearer, we could eliminate the "exterior" perception entirely and instead ask, "Is your thought of 7 + 5 = 12 realizable in my mind as well? If so, is this because our respective neuronal arrangements are/must be identical?"

I don't want to lose sight of this exchange between Jamal and Hanover. Hanover is uneasy with the idea of an “intersubjective” way-station between individual subjectivity and some kind of “divine” objectivity which presumably would include knowledge of the noumena. I think the distinction Jamal is making is quite innocent, and conforms well with our experience and practice. I see a dog but for some reason have doubts. So I invite my neighbors to have a look. Together, we agree that I’m not deceived. Further doubts could resolved by a zoologist, post mortem, I suppose. But the point is that my increasing confidence in my subjective judgment never approaches statements about “reality” of the sort that concerns Hanover. We could all be deceived about the “reality” of the dog if you want to limit the use of “reality” to “what the noumena reveal”. But this isn’t how humans (other than philosophers!) operate, and Kant surely wasn’t doubting this intersubjective version of reality. On the contrary, his entire project is to make sense of it, to understand what would have to be the case in order for it to exist.

As for the question about mistaken or invalid reasoning, this seems to me an argument in favor of intersubjectivity. It’s precisely by engaging in rational discussion with others that we’re able to correct our mistakes. Could we all be simultaneously mistaken? Sure, but only more rational investigation will tell. And same point as above: None of this back-and-forth around possible mistakes has any bearing on a “reality” that would put us in direct contact with Kant’s noumena.

No, I think your OP is right. I suppose it depends on whether we can really imagine that "identical B-minimal properties do not entail identical P-regions". This degree of abstraction requires that B-minimal properties could be successfully identified without specifying P-regions, which seems doubtful. What is one of these "properties" supposed to be, anyway, if it isn't defined by its location in space-time? But I guess I'm just calling into question the intelligibility of the whole multiple-realization model. It may not depend on which way we go on B-minimal properties, but rather on whether functionalism, broadly interpreted, can make sense of the physical/mental world at all. Time will tell . . .