You had suggested back on page two that we might dissolve the notion that perceptual error had occurred by shifting the form of our explanation from "seems Y because is X under conditions Z" to "seems X under most conditions, but sometimes seems Y". That might work in the case of colors (for instance) where we are perhaps already comfortable with the idea that there is no fact of the matter, but it works less well in contexts where that doesn't hold, for example, like the time I thought I saw John sitting on my sofa but upon further review it turned out to be Pooh Bear. In that case I probably want to use an explanation of the original form (e.g. "seemed like John because is Pooh and Pooh has the same size and complexion as John, and I wasn't wearing my glasses, and I heard John's voice coming from that direction, etc..."). I wouldn't want to explain my experience via a schema that forces me to give up on the idea that it really was either John or Pooh sitting on my couch unless I have some additional reasons for thinking otherwise.

Not sure if that helps, but it's the best I can do.

I need to think about this some more Aaron, but my immediate take is that the difference between seeing John instead of seeing Pooh, that is the perceptual error, is a difference within the context of perception between what I thought I saw and what I discover, on further investigation, that I had really seen. — Janus

Sure thing. I don't disagree with what you wrote above, so maybe there was just a misunderstanding prior?

It's not about being "sure", or even correct. It's about the structure of the concepts that we deploy in order to explain our (purported) perceptual mistakes.

The concept of perceptual error is probably generalized out of the recurrent experience of having our expectations or desires unfulfilled. The formula "seems y because is x, under circumstances z" (or whatever) is a further generalization that helps us explain why particular perceptual errors occur. So when I walk into work in the morning and notice that my purple tie looks green, I will leverage an explanation that satisfies the aforementioned form (e.g. "my purple tie looks green because of the black lights installed over my cubicle"). So it's not that that perceptual error arises because we say "X is Y, but looks Z under the current circumstance" rather we leverage that formula as a way of explaining the experience of getting things wrong.

In regards to leveraging a formula that says something like "X looks Y under most circumstances, but looks Z under others" won't eliminate perceptual error because we still can't help but make claims about how things really are, and we will still inevitably get things wrong from time to time. If I look into my parlor and say to you "John is sitting on my sofa in the parlor right now", but really it's just my daugher's life-sized Winnie the Pooh stuffed animal (for example) that is sitting on the couch, it won't help to try to formulate an explanation in terms of this Winnie the Pooh stuffed animal looking like Winnie the Pooh under most circumstances, but looking like John in other circumstances. First of all, my one-off mistake is probably not generalizable/repeatable in that way. But more fundamentally, the fact of the matter is that it's just Pooh-Bear sitting on my couch, not John, and that's that.

A more neutral descriptor might be 'need for a conceptual anchor' where the need is less a personal need of the thinker that something impersonally generated from within the conceptual game. — csalisbury

Ah. That makes more sense.

I do think the conceptual analysis holds, as a kind of historical-philosophical narrative, even if you strip out the desire stuff, but I'm not sure. — csalisbury

So we've generalized an explanation of the form "seems y because is x, in circumstance z" that helps us understand/cope with particular cases of perceptual error. Even if we posit something akin to desire as a prime mover within the dynamics of experience, why take the next step and universalize the formula to all possible experiences? Is it desire pushing us to look for an explanation where none exists? Or is it just bad metaphysics?

At that point the whole scenario slips into incoherence. Doesn't that seem like a problem?

That's an interesting analysis, although in ascribing a motive as you have behind the postulation of a noumenal realm I'm doubtful of the universality of its application. I have to imagine that sometimes people are just legitimately confused regardless of their desires. I know I am. :)

As for Sellars, he basically overlays the phenomenal/noumenal distinction over his own manifest/scientific image distinction, a move that I find to be both unjustified and uncompelling. So while he doesn't fall into the trap of noumenalizing the void, he strips the manifest image of all ontological authority by granting scientific claims the ability to act as defeasors for any all manifest claims despite the complete and utter absence of any actual experience of error.

In any event, it seems like there's an ambiguity in the concept of the noumenal "is", it's meaning changing depending on whether or not someone is reifying the void. If they are reifying the void, the noumenal "is" becomes incoherent. If not, then it collapses back into the "is" of everyday experience (i.e. one half of the is/seems couplet that Sellars describes).

So am I understand this as having no epistemological consequences? In what sense, then, is it a response to Descartes? — Snakes Alive

Of course it has epistemological consequences - it totally inverts the Cartesian approach to knowledge. Instead of employing methodical doubt, retreating to "seems" claims and then trying to define "is" claims based on criterial modifications therein, it does the opposite. In the process it also lessens the temptation to reify "appearances" into the direct objects of perception.

That's not Sellars's claim. His claim is that the concept of "seems" is parasitic on the concept of "is". We can't understand what it means to affirm that "It seems that X is Y" unless we understand what it would be to affirm "X is Y". Another way to put this would be to say that to understand what it is to have a non-veridical experience one must understand what it is to have a veridical experience. "Seems" talk modifies "is" talk via the withdrawal of assent. That is the sense in which "is" talk is conceptually prior to "seems" talk, according to Sellars.

I think you're heading down the right track. There's two separate but related lines of questioning at play here. First there is the question of whether the achievement of knowing can be analyzed in purely causal/empirical terms. Second is the question of whether empirical description forms a realm of discourse that is semantically independent of all others. Sellars answers "no" to both questions. In the first case this is because he thinks there is an ineliminable normative aspect to knowing. To know is not just to engage in certain causal relations in certain reliable ways, but also (in some sense) to do what ought to be done. In the second case this is because empirical description presupposes an understanding of various modal and normative concepts that cannot be reduced to mere descriptions. In both cases normativity plays a key role in explaining Sellars's denial, but for slightly different reasons.

As on poster in this thread pointed out, the odd thing about this debate is that none of the positions is without problems. — Marchesk

Is that really so odd? I'd say it's the rule rather than the exception!

I think the title of your post obscures the meaning of Sellars's statement, which is really that to attribute knowledge to an agent is not to provide an empirical description of that agent. In other words, knowing is not reducible to an empirical state.

I agree that we need a concept of stasis (as well as concept of unity and identity) in order to think about change; I haven't been arguing against that. I have been arguing against reifying such concepts, and imagining that there are real entities which correspond to them. — Janus

Your original claim was that Being is identical to becoming. I am trying to undermine that claim by showing that becoming (change) presupposes something more fundamental and, as such, cannot be identical with Being.

However, I am not arguing here that Being is some eternal, immutable, first cause. It seems to me that the reification of Being is incoherent. Unfortunately, we can't seem to help but reify it in the course of attempting to think about it. At the same time, we can't help but think about it.

This seems to suggest that metaphysics (in the classical sense) is both inevitable and impossible at the same time.

And a state of everythingness is effectively a state of nothingness anyway. — apokrisis

Isn't this a contradiction?

Say it is temperature that is fluctuating; there is no changeless entity: temperature that is fluctuating; the fluctuating is temperature, since temperature is never changeless. — Janus

But there is presumably some stable entity that has a temperature, which endures through fluctuations in its temperature.

I would say there are changing unities, identities and wholes in nature; but I wouldn't say they are "out there" in any absolute sense. — Janus

I'm not concerned with absolute vs. relative at the moment. I am only now concerned with the question of whether the concept of change depends on the concept of stasis such that we cannot think change without also positing an underlying unity or substratum.

Wrong question. If nothing has yet been prevented from being the case, then what isn't the case? — apokrisis

I'm not sure how to answer this. The answer that the question seems to beg for is "nothing", but that seems incoherent.

The fluctuation fluctuates?

Not exactly, I am saying that changeless unity, changeless identity, and changeless wholeness are mental abstractions. — Janus

Is there any sense in which we can say that there are unities, identities and wholes "out there" in nature? Must we not say, then, that there is some principle of unity at play within nature itself? And furthermore, how is it that the mind is capable of creating such abstractions in a world of pure change?

Alternatively, change could be fundamental and somethingness is what we get when unbounded fluctuation is stably bounded. — apokrisis

But what is it that is fluctuating in the first place?

The identity of entities is that which is understood to endure, but the notion of changeless endurance is an abstraction. — Janus

What do you mean by that? Are you saying that unity/identity/wholeness exist as an abstraction only in the mind?

Doesn't change presuppose something that changes? Isn't this something more fundamental than the changes that it undergoes?

What are your thoughts on the claim that Being and Nothingness are identical? Being is not a being. But if Being is not itself a being - if it is not a something - then it is Nothing. There's an unresolvable paradox lying at the heart of metaphysics. The mind, in its attempt to conceptualize Being, necessarily reifies it. Thus reified, Being becomes an object of thought among other objects. But this is precisely what Being is not. So what follows? Metaphysics, as a science of Being, is impossible. There are no metaphysical depths lying beneath the surface of everyday experience. Beneath the roil of experience, there is Nothing.

By "indivisibility" I simply meant that you couldn't take someone's consciousness and split it into pieces. At least, I am not aware of any phenomenological descriptions of such a thing. I'd consider things like thought, feeling and imagination to be more akin to categories or features of consciousness.

Repeating an assertion doesn't make it true.

Vacuous.

Oh, and I forgot to mention - you still haven't addressed the problem, which is the disanalogy between superconductivity and consciousness. The former is quite obviously a property of materials, whereas the properties of the latter are manifestly not.

Do you think that the state of superconductivity is something over and above the concrete material substrates that exemplify it? If yes, then you're not a materialist. If no, then your use the term "emergence" is essentially vacuous.

I agree that materialism faces massive conceptual difficulties when it comes to explaining the mind, but dualism faces many vexing problems as well. While we all have our leanings and biases, in my opinion humility dictates admitting that we simply don't know.

What does 'identical' mean to you? Because even I may not agree that the mind and the nervous system are "identical." — Uber

Identity is typically expressed in terms of properties - X and Y are identical just in case they have all of the same properties. From this perspective, it seems perfectly reasonable to speak about some particular quantity of high-temp super conductor being identical with a particular quantity of suitably manufactured oxides and carbonates. We might not understand how exactly how those preparations result in a material with superconductive properties, but there's not really any question of the plausibility of superconductive properties belonging to a suitably prepared material substrate.

Compare this to the case of the mind and the nervous system where there does not seem to be any overlap of properties whatsoever. The terms used to describe the nature and structure of subjective conscious experience seem to be completely disjoint from those used to describe even the most globally emergent properties of the nervous system. It's very difficult to see how the mind, with its apparent indivisibility, intentional orientation toward the formal and final objects of thought, privacy of perspective, capacity for conceptual abstraction and self-reflection, and other curious features, could ever fall out of a purely material analysis of any physical system. I would suggest that to pretend otherwise is simply to bury one's proverbial head in the sand.

I'm not quite sure what point you're making here. That because we don't have a model for something physical, then it's not physical? — Uber

No, I was undermining your analogy between the mind/body problem and the problem of super-fluid states.

Should physicists believe that high-temp superconductors are not physical because they don't yet have a 'model' for explaining such phenomena? — Uber

No, but in the case of high-temp superconductors, there are no a priori reasons for thinking otherwise. It's not hard to intuitively accept that the properties of high-temp superconductors will fall out of the dynamical behavior of the substrate. Things are not so clear in the case of consciousness.

So the details still need to be finished, but the general idea is already there: consciousness is an emergent physical state. — Uber

I think that you are underestimating how counter-intuitive the materialist thesis is. It's not simply a question of dependency, but a question of identity. The form of materialism being criticized in the OP doesn't merely claim that the mind depends on the operations of the nervous system - even a dualist can accept that - but, that the mind is identical with said operations. You may believe that, but as the OP points out, it amounts to little more than faith at this point.

A superfluid state can be very different from the helium atoms that collectively interact to produce the state, but we don't then conclude that superfluids are not real or physical. — Uber

The difference is that we have a model that explains how the properties of a superfluid state arise from the dynamics of the underlying substrate, but I don't believe we have such a model in the case of mental states. To my knowledge, we have no model that explains why experience should be one way rather than another given the dynamics of the underlying substrate.

, basically what you are saying is that, within a given context, the proposition "I have hands" is either true or it is false. In other words, either I really do have hands or I don't. As such, it it is not possible that "I have hands" and "I don't have hands" are both false within the same context. Therefore, it is not possible that I could always be wrong no matter what I believe, because something has to be the case.

Makes sense to me.

The trilemma overlooks the possibility of self-justifying acts. The norms of rationality seem to fit the bill here because one cannot question them without employing them and thereby implicitly endorsing them.

Thanks for the reply. It seems that you are of the view that I cannot really get what I am asking for. You might be right. — PossibleAaran

Well, honestly I'm not sure if I really know what you are asking for. You asked for a reliable method that yields realist beliefs about macroscopic objects, where "reliable" just means "likely to produce true beliefs when used under the right circumstances". But this is all very vague.

Suppose that I come to hold realist beliefs about macroscopic objects on the basis that my parents told me so. My parents tell me the truth far more often than not and so this satisfies your criteria, but something tells me this won't satisfy you. Why or why not?

Perhaps. That sounds like quite a strong argument to me. One issue which I am thinking of is this. Classical Physics can be interpreted in an Idealist fashion, so as not to posit anything which exists unperceived. Doing so would not conflict with any of the available evidence. Presumably then, the Idealist interpretation of classical physics would work just as well as the Realist one would. It is just a contingent truth that we happen to use the Realist interpretation. But then, couldn't this argument of yours be made in favour of Idealism? The fact that the Idealist interpretation works so well is best explained by the hypothesis that it is correct - that things do not exist unperceived. — PossibleAaran

The difference is that the idealist accepts beliefs that prima facie contradict the assumptions made in the model itself. The realist will argue that the simplest meta-level hypothesis is that the model works because the assumptions are really true. The idealist has a number of interesting responses that they can give to this. As we've discussed, I'm not suggesting that the realist can wield the scientific method to disprove idealism because strictly speaking the scientific method does not "prove" or "disprove" anything at all. If you are looking for a reliable method that can be used to draw conclusions that only the realist can accept, then I believe you are indeed out of luck. The idealist can add meta-level hypotheses to any theory in order to make it consistent with idealism.

I do take the scientific method to be reliable (dropping issues about "the" scientific method). But it seems to me perfectly possible to interpret the findings of science in an Idealist way, without doing anything that contradicts the evidence. That classic scientific theories assume that things exist unperceived is a kind of bias of those theories. It isn't needed to make sense of them, so far as I can tell. It just requires imagination and the willingness to entertain views which are different to what we ordinarily accept. — PossibleAaran

But wait, you asked for a reliable method regardless of whether it could be proven to anyone or not. Now that one's been provided you're backpedalling!

Yes, the idealist can always find a way to make the evidence consistent with his/her position. That's an easy thing to do, as any conspiracy theorist well knows. It's certainly possible that objects pop in and out of existence in just such a way as to be consistent with the predictions of classical physics. Or maybe, just maybe, classical physics works so well precisely because its assumptions about macroscopic objects are accurate!

There's no strictly logical way to decide the matter, and reasonable people can disagree. We can start wheeling out concepts like "parsimony", "simplicity", "explanatory power" to argue our respective cases, but at the end of the day it really just comes down to aesthetics and choice. You seem to be haunted by the the prospect that you might be wrong. Get used to it. Such is life!

In another sense, I 'know' that P only if there is some reliable method by which I could establish that P. Note that reliability is a de facto concept. A method can be reliable even if I have no way of proving that it is reliable to anyone who doubts it, and even if I couldn't prove it to even a single person. For a method to be reliable is merely for it to be a method which, when used in the right circumstances and in the right way, produces beliefs which are true more often than not. — PossibleAaran

Do you consider the scientific method to be "reliable" in the sense you describe above? If yes, then it seems you could stake a claim to "knowing" that objects exist unperceived on the basis that it is assumed by the models of classical physics.

It is true that classical physical theories assume that things exist unperceived, but this is hardly a justification of that claim. — PossibleAaran

Quite right. The justification for the assumptions built into the model is the empirical adequacy of the model as a whole. This is a pragmatic rather than a foundationalist approach to justification. Remember, we're just looking for "good reasons", not "deductive proof".

The theories predict that 'if objects disappeared when unobserved then there would be observable consequences'. What would those consequences be? It seems like the hypothesis that things only exist when perceived has all of the same predictive consequences as the hypothesis that they exist also unperceived. Perhaps I have missed something. But if so, it would be good to be clear about what. — PossibleAaran

For instance, classical models predict that if the planet Jupiter ceased to exist every time that no one was looking at it, then the earth would be displaced from its current orbit with catastrophic consequences for its inhabitants. This obviously doesn't happen.

I'd be interested to get your thoughts on what constitutes a "good reason" for believing that objects continue to exist when they are not perceived. You mention observation and inference, so let's head down that path a bit.

Consider classical physics. It is it reasonable to claim that classical physics is the best available model for understanding the motion of inanimate, macroscopic objects? Classical theories assume continuous trajectories and temporally persistent masses. They predict that if objects disappeared when unobserved then there would be observable consequences that we simply do not experience. A reasonable explanation, given the assumptions built into our best model, is that those objects don't disappear when unobserved, but continue to exist much as they were when last observed.

Is this philosophically air-tight? No. Is it reasonable and responsible for the purposes of belief? No question.

What are your thoughts?

Aquinas is saying that a phoenix has an essence (or, put differently, that there is a phoenix essence - "what a thing is") even though phoenixes don't exist. That becomes the basis for his distinction between existence and essence. — Andrew M

Indeed, that is one of the arguments that is often given. I was trying to steer us away from that particular line of thought because it takes us pretty deep into epistemology. In scholastic terms, phoenixes do not have "subjective" existence - that is, they are not mind-independent subjects of existence. However, they do exist "objectively" - that is, mind-dependently. Qua objects of thought, phoenixes have a form all their own. Indeed, it is via such forms that we classify imaginary creatures into "this" or "that" type. When I imagine a particular phoenix, I am objectively instantiating the form "phoenix".

This would have been foreign to Aristotle, who held that valid (formal) distinctions can only be made on the basis of existents (particulars). — Andrew M

Yes, all formal distinctions trace their ultimate genesis in subjective reality as appropriated by the senses. A more metaphorical way to put it is to say that all distinctions are woven from the raw materials provided by the senses. That doesn't imply that every formal distinction is a real distinction, and I believe that Aristotle recognized that distinction to some extent.

It is not the form that exists (or not), it is the particular. — Andrew M

If a particular's form (essential nature) does not exist in its own right, then a particular's existence cannot be identical with its form (essential nature) and there must be a real distinction between a particular's essential nature and its existence. This is exactly what Aquinas is arguing for.