What's rigid is that their referent doesn't change with respect to world of evaluation. See the attitude report example above.

It's not relevant to what a rigid designator is. Calling something a rigid designator isn't a claim that it can't change in meaning over time. That has nothing to do with it. All words can change meaning over time, rigid designators or not.

OK, I don't agree with that, but I'm not sure what the point is anyway. Is the point that the meaning of words can change over time? I agree, but that's not relevant to the question of what a word means.

I don't know what you mean by 'to person S.' Generally we talk about what a word means, not what it means to someone.

All claims about what a word means are claims about what it means at a certain time. I'm not sure what you're getting at.

For example, if I say that 'tree' means tree, and always picks out trees relative to a world of evaluation, it's not a rebuttal to say that 'tree' might have meant turnip instead. That's just irrelevant. The point is what the word means, not what it might have meant if the language were different.

Also, the fact that a name might have referred to something else doesn't mean that it might not have been a rigid designator. It just means it might have been a rigid designator designating some other thing. The claim is that proper names as a class are semantically rigid designators, whatever they refer to.

But what a word means is simply what people use it to mean at any given time. That can shift (and it's also not universal). So it wouldn't be rigid. — Terrapin Station

Again, a claim that something is a rigid designator is not a claim that it must mean something or couldn't have meant something else. It's a claim about what it actually means.

For reference, the technical notion of rigid designation makes no sense outside of an intensional semantics and typically is cast in terms of possible world semantics. So it's a technical notion, but it has intuitive consequences, like what I talked about with attitude reports above. The intuitive notion of what rigid designation is can be seen from these sorts of examples, and intuitions about what makes a sentence true, independent of the formal framework.

But if you want to know concretely what rigid designation means, knowing a bit of modal logic is helpful. In modal logic, values or extensions are given relative to possible worlds: the point is just that something is rigid if the possible world with respect to which it's evaluated makes no non-trivial contribution to its value. So names are still, like in non-modal logic, behaving like individual constants, that just denote some individual.

Do you just mean its truth value? — Terrapin Station

Yeah, the value of a proposition relative to a world is a truth value. The value of a name inside the sentence expressing that proposition relative to a world is an individual. The point is that, regardless of world of evaluation, the name will always refer to the same individual.

Formally, if you like, the semantic value of a name can be represented either simply as an individual, or as a constant function from worlds to individuals, making the world of evaluation vacuous. This contrasts with definite descriptions like 'the president,' which are represented by non-constant functions from worlds to the president in that world (which might be different individuals in different possibilities).

in those cases, though, just how are any designators rigid? — Terrapin Station

Because the issue is not what the words might have meant, but what they do mean. Given what a name does mean, its value doesn't change over possibilities. This is different from non-rigid designators like definite descriptions, which can contribute different individuals depending on the world of evaluation, even holding fixed what they mean.

its value is invariant over possibilites by virtue of what? — Terrapin Station

I'm not sure what you mean. Are you asking why names mean what they mean? That's a complicated question: the more basic descriptive claim is just that they mean a certain thing, which we can see even without knowing why they come to mean this.

Rigid designation is about the evaluation of a proposition at a world, given the way that it's used. That names could mean something else, or refer to different individuals, if the language were different, doesn't make them any less rigid designators. What a word means is contingent, but given what a name means, its value, the individual it refers to, is invariant over possibilities.

So if you use modals or attitude reports, what makes the modal true can depend on different individuals if you use a non-rigid designators:

Sue thinks the president is incompetent.

Sue can think this without believing the president is any particular person: she simply believes that the unique person who is the president, whoever that is, is incompetent (she might know it is Michael, or might not). Her belief will be validated by any individual being incompetent, so long as s/he is the president. But

Sue thinks Michael is incompetent.

Sue can only believe this if she thinks some particular person, namely Michael, is incompetent. And only Michael's incompetence is relevant to her belief being true.

dun't matter what you're modeling.

You can define entailment model-theoretically. For any model, if if A is true relative to that model, then B is true relative to that model, then A entails B.

I don't know, I think women are just more interested in social cohesion and taking part in social institutions. Men tend to have slight asocial (anti-social?) streaks.

Alright, man.

Why would I engage with you if you're going to be disingenuous?

Are you aware of the origins of the experience machine thought experiment? If so, is there something you want to use it for?

Maybe I'm not making myself clear. I don't deny that there's a substantive ethical question to entering the machine. What I deny is that it can have the epistemological import that e.g. Nozick wants it to.

Would a Cyrenaic choose to enter the machine? It's an odd question, in a way, since the Cyrenaic seems committed to thinking we already are in some such machine, and would deny that one could know that one was entering such a metaphysically-altered state, since one does not even know one's current metaphysical state.

If pleasure is the good, it might seem like the decision is mandated, but then, the Cyrenaics don't seem to care about mandates, and there is no ethical code that obligates them to maximize their own pleasure, present or future. So based on present whim, if entering the machine seemed distasteful, they could refuse, to the extent they understood this as a mere practical action, devoid of metaphysical implications. With metaphysical implications, they could deny that they can coherently imagine the situation Nozick asks us to imagine. And if we're to take Nozick seriously about the 'indistinguishability' of the experience machine from veridical life (that is, it is not just an accident, like there existing children being tortured behind a screen that by happenstance we just couldn't see), then we have the fallacy I mentioned above.

The point of experience machine thought experiments is that it is supposed to cause a problem for positions that rely for some consideration, ethical or otherwise, that it be confined to apprehensible distinctions having to do with experience.

But it causes no such problem since, by the nature of the thought experiment, the experimenter access the distinction experientially so long as the experiment is coherent on its own terms.

Whether the person who would enter the situation could tell the difference or not is irrelevant.

Yes, but then the thought experiment has no teeth.

What matters in making the moral judgment is whether the imaginer can tell the difference, not the imagined.

The point is not that people couldn't prefer such a thing. It's that the thought experiment's coherency hinges on us being able to imagine something which it stipulates is not imaginable. It's coherent to want to be plugged into the Matrix: what isn't coherent is to believe that this is coherent, while the possibility of distinguishing between the Matrix and the real world is incoherent.

It doesn't matter: by your own example, the episode must be such that the viewer can tell the difference, and therefore there is such a difference. That the crew doesn't know is irrelevant: the point is if they did know, whether they would prefer to leave the holodeck. The same is true of our trapped philosophers. As for the philosophers imagining the experiment, they must know the difference for the thought experiment to work, so from within the imagining situation, they are justified in not preferring the experience machine, on whatever ethical grounds they want (if they're inclined to disprefer it).

I believe that the experience machine thought experience is subject to a kind of logical fallacy that is common in many thought experiments. The problem is something like this: we want to construct a thought experiment which, by stipulation, involves a situation in which we can't distinguish between two things (being hooked up to a machine and real life). But also by stipulation, the thought experiment itself asks us to distinguish these two things. So it is that the experiment only remains coherent so long as we slide from one to the other in our reasoning.

The reason being hooked up to a machine horrifies some people is because there is a detectable difference between the two (which is why movies like the Matrix, in which Neo comes to find out about this situation, are coherent to us). But then, the experiment falls through because this detectable difference will allow us to coherently prefer being outside the machine rather than in, whether on hedonistic grounds or not.

If on the other hand we take the thought experiment seriously in claiming that we cannot tell the difference even in principle between these two situations, then we lose our ability to coherently imagine the situation that the thought experiment asks us to, and so we cannot claim that such an imagined situation would be bad, because we cannot imagine it ex hypothesi.

From what TGW wrote of the Cyrenaic view of the good, it would seem perfectly consistent for my good to be your bad. — Marchesk

This is a little tricky, because the Greeks don't typically speak in terms of 'my good' versus 'your good;' they just speak of the good. If pleasure is the good, it isn't my good, although it may be a good that I am undergoing rather than someone else, and so one that I have a special epistemic relation to.

What is true is that one individual thing may have good and bad consequences, i.e. may be instrumentally good in some ways and bad in others, and that these goods and bads may be the pleasures and pains of separate people. But the only things that are intrinsically good and bad are pleasures and pains, and here it makes no sense to say that someone's good is someone else's bad.

If it causes me pleasure to torture you, and all goods are subjective and only definable by each individual, — Marchesk

Goods are not subjective on the Cyrenaic view in any fundamental way: pleasure is good tout court. There is a subjectivity in that pleasure is dependent on the existence of what we might call a subject, i.e. an undergoer or mover experiencing the pleasure. But this does not mean that it is in any way a matter of opinion or subject to substantive faultless disagreement which things are good and which not, nor does it mean that anyone ever defines what is good.

then there is nothing wrong for me to torture you, as far as I'm concerned. — Marchesk

It's important to remember that it most Greek ethics there is no 'as far as I'm concerned' as far as the good goes, though there may be goods or bads that disproportionately affect some people over others. Also, the term 'wrong,' or some equivalent, is not used to express these views.

You can't imagine a guy chopping down seventy trees unless you literally picture a tree chopping event seventy times over in your head?

This is such a parlor game answer.

1. Is it ever ok to remain skeptical of an "absurd" conclusion to a clever argument even when one can't pin-point the exact flaw in the reasoning? — Aaron R

Sure, but it's also appropriate to remain skeptical of your dogma when given a good argument to the contrary that you can't refute and that poses devastating problems for it if it holds, rather than continuing to assert it.

I mean, you can be dogmatic, but then you're just admitting you'd prefer not to do philosophy, so I don't see why you'd ever have a philosophical discussion about it. Just state your conclusion without evidence and hold to it in spite of any evidence to the contrary – that's what you're proposing, and how can any philosophical discussion challenge such a strategy? It's a core difference of goals, which is why I wonder why philosophers bother making such claims, rather than just not doing philosophy in the relevant area.

Then I tell myself seventy times — Metaphysician Undercover

Really? That seems exhausting and pointless, and not the way people imagine things.

Did you picture someone going out and cutting some christmas trees, or did you think about what it means to cut a tree, and then multiply that by seventy? — Metaphysician Undercover

No, which makes me think these notions of imagination have to be wrong.

OK, and that other thing would have to have experiential consequences, or else the example could not work by its own logic without begging the question.

But the drug in the water is not experienced; or at least it is not known to subjective experience. — John

Yes it is, by the fact that you feel funny if you drink the water. This is baked into the very example.

When you say "I can imagine such a situation without difficulty", are you really sure that you can, — Metaphysician Undercover

Yes

Not at all. The idealist simply equates the presence of a drug in the water with a certain connection of experiences. No inference to something non-expeirential is required.

Right, but then you're back to assuming your conclusion. The realist will just deny that they're imagining experiences. They'll say they're imagining a tree, and part of that imagination might involve them having experiences in the imagining situation, but this is irrelevant. Not sure where your argument is supposed to go from there, unless we futz around with the semantics of 'imagination,' which doesn't seem promising.

The idealist would say there is nothing to perceiving drugged water other than perceiving the experiential consequences of water being drugged, which might include an odd color, but would also include feeling funny on drinking it.

But I think the problem is that many realists do claim to be able to picture a tree that isn't being seen — Michael

They say you can picture such a thing because you can. If you are picturing a tree, the fact that you are picturing it in the imagining situation does not mean that anyone is picturing it in the pictured situation. This is the formal fallacy.

To think otherwise would be effectively to claim that every picture than an artist paints contains the artist in the picture: not every picture is a picture of the painter, just because you must paint in order to picture.

You don't just perceive some water; you perceive drugged water, since on drinking it you have other experiences of getting drugged. To say that the water remained drugged is just to say that these regularities in experience obtained, and your example in fact relies on this in order to be coherent.

Then you are using the word 'imagine' to mean 'picture solely experientially,' which would seem to linguistically guarantee your conclusion. All I can do is protest that this isn't what 'imagine' means, at least not if you want to marshal any of the relevant idealistic conclusions.

(At the very least, it would commit you to saying I can't imagine a man chopping down seventy trees, too strong a conclusion if this is supposed to imply that a man chopping down seventy trees is unimaginable and therefore somehow impossible).

I deny that in imagining a tree you are only imagining a tree's smell, etc.: you are, rather, imagining a tree. Its smell, etc. may be salient properties of it, but they're not equivalent to the tree, unless you assume your conclusion.

For example, if I'm told to imagine that a man chopped down seventy trees illegally and was sent to prison, I can do this fairly easily, but it's unclear to me exactly what sorts of smells and sights I am or have to be imagining, and those things seem not to be at all what's most relevant or present to my mind in imagining such a scenario (how tall are the trees? are they elms, or pines? what is the man wearing? what does the prison look like?). I'm not even sure I can consistently picture seventy trees together (as opposed to sixty-nine, after all), as if all in a visual or olfactory image. Yet I can imagine such a situation without difficulty: so you must be wrong.

Is a tree just a collection of experiential things?

If yes, you've assumed your conclusion.

If no, then in imagining a tree you have not just imagined a collection of experiential things, but a tree.

Whether you have experiences in imagining a tree is irrelevant.