The notion of rigid designators is a parsing into English of what Kripke did in developing his Possible World Semantics, the semantics - the interpretation - used in his formal completeness theorem. He has individuals - a,b,c, x,y,z, across multiple possible worlds. We know, therefrom, that if we adopt this approach, we will be working with a coherent, consistent and complete grammar.

Those grammars that adopt counterpart theory tend to greater complexity.

So to about p.174-5.

The juxtaposition here is between two ways of talking about possible worlds. On the one hand, we have the view that when we talk about the individuals in other possible worlds, it is not immediately apparent that they are the same individuals as in this world. Kripke uses Nixon for his example; we might modernise it while keeping the tone. What if Donald Trump were a prominent member of Extinction Rebellion? What things would be different? We might have fun with such considerations.

Someone will say "But wouldn't such a Trump no be so different to our Trump as to be a entirely different person? By what criteria could we consider a Trump who superglues himself to a petrol tanker or some such protest, to be the same Trump who approved the wholesale destruction of the environment? "

The picture here is of possible worlds as places we might visit, and inspect to see if some of the individuals there are like the individuals in our world. We venture into a possible world in which it makes sense to ask "Is that really Trump, blocking the bridge?"

The contrasting view is that possible worlds are little more than a way of talking about how things might have been, that, as I have put it elsewhere, possible worlds are stipulated rather than discovered.

When one supposes that Trump had joined Extinction Rebellion, one does not find oneself in the position of having to demonstrate that the supposition is about Trump. Here Kripke weaponises the question. As if the conversation might go:

"Suppose Trump had joined Extinction Rebelion..."
"Ah, yes, so how would you know that it was indeed Trump who had joined Extinction Rebellion..."

Well, I know because that was the very stipulation from which we began. It wasn't "Suppose that in some other possible world there was an individual with certain characteristics in common with Trump in our world who nevertheless was not Trump but who joined Extinction Rebellion..."

Possible worlds do not "exist out there, but very far away, viewable only through a special telescope" (p. 175). We make 'em up. And we make 'em up how we like.

A close error would be to suppose that possible worlds are the same as the multiverse of pop physics. These two ideas come from very different backgrounds. Any suggestion that they are the same thing would require considerable argument from both physics and logic.

P. 177 consist in a few simple observations about terminology.

(Edit: Apologies - a distraction prevented me finishing this post. I was thinking of just leaving it as is, since it's possible that this is the part that will meet with the most disagreement, and it would have been amusing to see if anyone actually read the page.)

It probably seems extraordinary now, but there had been a time where terms such as "analytic", "necessary", " a priori" and "certain" were treated as interchangeable. This is the article that brought all that into question. In that regard, p.177 is arguably the most influential page in the article under consideration.

Here are Kripke's definitions:

Two metaphysical terms:
Something is necessary if it is true and it could not have been otherwise.
Something is contingent if things could have been otherwise.

An epistemological term:
Something is a priori if it can be known independently of experience.

It should be clear that being a priori is quite different to being necessary. If they are related so that being one implied being the other, some philosophical argument is required in order to demonstrate that relation.

As Kripke says, "neither class of statements is contained within the other" (bottom of p.177).

The suggestion is that Kant took necessary and a priori to be interchangeable, and similarly for a posteriori and contingent. If he did, he was certainly wrong. That he did, I've not the background to decide. @Mww may be able to help here.

Metaphysical terms needs an edit.

synthetic a priori relations — Mww

There's this additional complication, the use of "synthetic" and "analytic" in the place of "necessary" and "contingent".

This seems to be equating a grammatical difference with a modal one. We supposedly know the truth of analytic statements just by considering their place in our language. But the truth of synthetic statements requires consideration of how things are in the world, hence usually involving experience.

So we might add to Kipke's list

Two grammatical terms:
Something is analytic if its truth can be known solely by the terms involved.
Something is synthetic if its truth is not known solely by the terms involved.

And again, what seems clear leads on consideration to a great deal of complication - including a long-forgotten discussion between Quine and Chomsky, of all folk.

It might suffice for our purposes in considering Kripke's article, to just point out that it is not obvious, without further consideration, that this grammatical distinction is the very same as Kripke's metaphysical distinction.

Metaphysical terms needs an edit. — Mww

Cheers, done.

The suggestion is that Kant took necessary and a priori to be interchangeable….. — Banno

There is a serious caveat here, in that for Kant, when he speaks of the a priori he means pure a priori, meaning having nothing to do with any experience whatsoever. He set this as a definition, probably so he didn’t have to modify the term every time he used it. Conventionally speaking, on the other hand, when the term a priori is used, or even when the uninitiated read CPR and find Kant using the unmodified term constantly, it refers to those conditions of no immediate experience, but grounded nonetheless in antecedent experience.

With respect to Kripke’s metaphysical terms, he actually says independently of ALL experience, which is Kant’s pure a priori, but a priori in its conventional sense, as most are inclined to use it, is not necessarily independent of all experience.

“…. In the first place, if we have a proposition which contains the idea of necessity in its very conception, it is a priori….”

“…..Now, that in the sphere of human cognition we have judgements which are necessary, and in the strictest sense universal, consequently pure à priori, it will be an easy matter to show. If we desire an example from the sciences, we need only take any proposition in mathematics….”

So it is that necessity and a priori are always connected, through the LNC, so if one wants to call them interchangeable because of that connection, I guess he could. There’s so much more to all this, that would show they are not, but…..some other time perhaps.

…..and similarly for a posteriori and contingent. — Banno

The a posteriori is always contingent, through the principle of induction, but again……interchangeable?
————-

There's this additional complication, the use of "synthetic" and "analytic" in the place of "necessary" and "contingent".

This seems to be equating a grammatical difference with a modal one. — Banno

Maybe equating the relational with the modal. Still a catastrophic rational error. Necessary/contingent are modal categories, which are logical conditions; synthetic/analytic describe relations of conceptions in propositions, which are relational conditions.

I see what you did here, letting me in without fear of court. I owe you a toddy. Or two.

Pleased that you noticed.

The a posteriori is always contingent, through the principle of induction, but again……interchangeable? — Mww

Notice that what you have said here is contrary to the stuff around p.167. So according to Kripke, that Hesperus is Phosphorus is known a posteriori, yet not contingent.

So there is disagreement between Kant and Kripke?

I'd like to consider the argument that uses the principle of induction. What is it? I gather that it also disagrees with Kripke's account.

But on to other considerations. Kripke has I think too much sympathy with antirealism. See Kripke's theory of truth.

So suppose our language were the whole of mathematics, and we adopted a constructivist position, such that a mathematical theorem is true only if there is a proof that it is true. We can adopt the antirealist position that the Goldberg Conjecture, since it is unproven, has the truth value "meh" - is neither truth nor false. — Banno

Here's were Kripke expresses just this view.

Here the emphasis is somewhat different, since the point at issue is that "it is not trivial that just because such a statement is necessary it can be known a priori... this shows that even if everything necessary is a priori in some sense, it should not be taken as a trivial matter of definition" (p. 178).

Ruth Barcan Marcus argued that if x is y, then x is necessarily y. Although Barcan treats Hesperus as a proper name, a simple tag devoid of any further content, the truth of (if x is y then x is necessarily y) depends on whether a proper name such as Hesperus refers to an object Hesperus that exists in addition to its properties or refers to a set of properties that have been named.

If a proper name such as Hesperus refers to a set of properties that have been named, I can understand and agree that if x is y then x is necessarily y.

How can a necessary identity statement be derived from a contingent identity statement
Kripke wrote: "most philosophers have felt that the notion of a contingent identity statement ran into something like the following paradox."
(1) If x is identical to y, and if x has property F, then y has property F
(2) Every object is necessarily self-identical
(4) If x is identical to y, then x is necessarily identical to y

This idea was reinforced by Wiggins, who said: "Now there undoubtedly exist contingent identity-statements. Let a = b be one of them. From its simple truth and (5) [= (4) above] we can derive ‘☐ (a = b)’. But how then can there be any contingent identity-statements?"

Kripke argues that Phosphorus is Hesperus is a necessary identity statement
Kripke first writes that the common view is that Phosphorus is Hesperus is a contingent identity statement: "We may tag the planet Venus some fine evening with the proper name ‘Hesperus’. We may tag the same planet again someday before sun rise with the proper name ‘Phosphorus’.............When, at last, we discover that we have tagged the same planet twice, our discovery is empirical...........Surely no amount of a priori ratiocination on their part could conceivably have made it possible for them to deduce that Phosphorus is Hesperus."

However, Kripke later writes that he believes that Phosphorus is Hesperus is a necessary identity statement: "To state finally what I think, as opposed to what seems to be the case, or what others think, I think that in both cases, the case of names and the case of the theoretical identifications, the identity statements are necessary and not contingent."

Is (1) really a contingent identity statement ?
Kripke is saying that although (1) is a contingent identity statement, (4) can be derived from it, but (4) is a necessary identity statement, which seems a paradox.

However, is it really the case that (1) is a contingent identity statement ? (1) in being a logical implication, involving the terms if then, is, in Kripke's word "an a priori ratiocination", independent of empirical experience. However, by Hume's problem of constant conjunction, we can never know from empirical experience that Hesperus is identical to Phosphorus, we can only infer it.

For example, I observe Phosphorus at 9am and Hesperus at 9pm having a 180 degree separation. As I don't know what happened in the intervening period, I very weakly infer that Hesperus is Phosphorus. I observe Phosphorus at 9am and Hesperus at 9.01am having a 0.25 degree separation. As I don't know what happened in the intervening period, I very strongly infer that Hesperus is Phosphorus. No matter how close the period of time between my observations, I can never determine just from a posteriori empirical evidence that Hesperus is Phosphorus. The most I can do is infer through logical reasoning that Hesperus is Phosphorus. My logical reasoning is a priori in the sense that it is independent of empirical observation, although my logical reasoning is based on a posteriori empirical observation

We can never know from empirical evidence that Hesperus is identical to Phosphorus, the most we can do is make the judgement from logic and reasoning based on evidence that Hesperus is identical to Phosphorus. (1) is a statement about identity that is based on logical reasoning about empirical evidence, and therefore cannot be described as a contingent identity statement.

As both (1) and (4) are statements of logical necessity of empirical evidence, this doesn't support Kripke's statement that "This is an argument which has been stated many times in recent philosophy. Its conclusion, however, has often been regarded as highly paradoxical."

So according to Kripke, that Hesperus is Phosphorus is known a posteriori, yet not contingent. — Banno

It’s is an empirical fact Phosporus is Venus, and, it is an empirical fact Hesperus is Venus. It is therefore an analytical cognition, hence necessarily true, that Phosporus is Hesperus, in that it is just saying Venus is Venus. Technically, this just means there are no conceptions belonging to the one that do not belong to the others. But it is nevertheless contingent, re: not necessary, that the second planet from the sun is called out by any of the names Venus, Phosporus or Hesperus, such names arbitrarily determined by whoever took it upon himself to assign them. As Kripke said, “it could have turned out the other way”, or, even moreso, the same planet could have been given any name that didn’t already belong to an object known to the one assigning. Nevertheless, identity belongs to the object necessarily, indicating how we are to be affected by it, as a function of our human sensibility, yet naming belongs to the agent’s cognition of the object, merely indicating how it is to be represented, as a function of our human intelligence.
———-

On the principle of induction:

“… Secondly, an empirical judgement never exhibits strict and absolute, but only assumed and comparative universality (by induction); therefore, the most we can say is—so far as we have hitherto observed, there is no exception to this or that rule. If, on the other hand, a judgement carries with it strict and absolute universality, that is, admits of no possible exception, it is not derived from experience, but is valid absolutely à priori.…”

Knowledge is experience, experience is always changing with time, so knowledge is always changing with time, therefore knowledge is contingent on time.

“….. Experience no doubt teaches us that this or that object is constituted in such and such a manner, but not that it could not possibly exist otherwise…..”
————

So there is disagreement between you and Kripke? — Banno

Of course, in that he is analytical, I’m continental, with all the implications carried therein. But he’s famous, got letters after his name, might even hold a chair, and I’m none of that, so…..

@Banno
Are we up to the wooden lectern?

It is therefore an analytical cognition, hence necessarily true, that Phosporus is Hesperus — Mww

I am surprised you say "hence necessarily true, that Phosphorus is Hesperus", as you also quoted Kant from the Critique of Pure Reason: "Secondly, an empirical judgement never exhibits strict and absolute, but only assumed and comparative universality (by induction); therefore, the most we can say is—so far as we have hitherto observed, there is no exception to this or that rule". (B4)

Running low on chilled Perrier over Christmas ? :smile:

I see something in the morning sky that is bright, visible, ringless and name it "Phosphorus". My knowledge that there is something in the sky is a posteriori. As I could have chosen any name, the connection between the name "Phosphorus " and something in the sky is contingent.

Henceforth using the convention that "Phosphorus" exists in language and Phosphorus exists in the world as a set of properties.

After looking at the sky on successive days, I infer that Phosphorus is Hesperus a posteriori. The connection between Phosphorus and Hesperus is contingent because it is an inference.

I can then say "I believe that Phosphorus is Hesperus". As I can only infer that Phosphorus is Hesperus a posteriori, the statement "I believe that Phosphorus is Hesperus" is synthetic

For convenience I rename both "Phosphorus" and "Hesperus" as "Venus". As I could have chosen any name, the connection between the name "Phosphorus" and "Venus" and between "Hesperus" and "Venus" are contingent. The statements "Phosphorus is Venus" and "Hesperus is Venus" are synthetic, as I can only know that Phosphorus is Hesperus a posteriori.

However, even though I can only know Hesperus and Phosphorus a posteriori, and as I can only infer that Phosphorus is Hesperus, then Phosphorus being Hesperus can only be contingent, the statement "if Phosphorus is Hesperus then Phosphorus is necessarily Hesperus" can still be true, as it is a logical implication.

This might be the first time I've somewhat followed along with Kripke. I've tried him before only to give up.

The molecular theory of heat part of the discussion had me really interested. I don't think I'd say that the case of molecules is the same as the case of the lectern, though, or the sensation of heat. One of the most obvious differences is that "H2O" does not pick out any particular molecule -- that's something that's always interesting to me about chemistry is that it looks at physical systems in aggregate, and if aggregates have names then there are as many aggregates in a sample of water as there are the factorial of molecules (EDIT:I might have that technically wrong -- it's been more than a minute since statistical mechanics, but the factorial of the number of molecules will get you in the ball park of the number of subsets. I can't remember when substitution is and is not allowed), and "H2O" could pick out any one of the groups within. So it doesn't really name any one of the molecules but rather says "of the molecules that are here they are composed of two hydrogen and one oxygen" -- but that, too, is funny because we don't really "see" molecules. If we're defining heat in terms of sensation, then molecules should be the same and what we actually interact with are properties of matter, and molecules are used to explain the properties of matter.

Which is to say, I highly doubt that "molecular movement" is a rigid designator -- same with water and heat and H2O. Not only could it have been otherwise, it's still possible for water to not be H2O. We just happened to build our theories like that and like them this way.

But, that doesn't speak against the general argument, only that particular example (and, I actually wonder, given that particular example -- would the analysis go the same for the mind-body problem as Kripke lays it out?) I just think that particular example is much too complicated -- the lectern example seems to work for me. And, in general, I think there's something to names being rigid designators, and I agree with Kripke that there's no reason to give predicates a priority over names -- that's just putting rigidity on the other side of the predication, so would fall to the same sorts of doubts.

((EDIT: As an afterthought, now -- might be a good example to set out "equiprimordial", but in analytic terms -- seems to have a similar meaning))

I am surprised….. — RussellA

Explained in the rest of what I said, maybe? Note the CPR quote references universality with respect to empirical judgements, where I referenced necessity with respect to analytical cognitions, both under the a priori umbrella.

That there are two names representing a singular whole object makes explicit the conceptions by which the first name represents that object, reside in the second name equally, such that the second name represents exactly the same whole object, hence “Hesperus is Phosphorus” is a pure analytic proposition, hence necessarily true. It is no less analytical than the proposition “bodies are extended”.

Now you might say, to point to one is not to point to the other. But one does not point to a name, but the thing represented by the name, so he points to the same thing, the same aggregate of conceptions, even if not the same name.
——————

As I could have chosen any name, the connection between the name "Phosphorus" and "Venus" and between "Hesperus" and "Venus" are contingent. — RussellA

Yes, the names are contingent, fully arbitrary, yet usually related to something antecedent to the name itself, in this case a combination of Roman and Greek gods. Nevertheless, the conditions under which the names are chosen, the connection between the representation and that which is represented, is not contingent, but given a priori in the synthesis of conceptual representations with sensory representations, which makes any name itself a mere representation. The names of the gods are just as analytic and necessarily true, insofar as the Greek god Phosphorus cannot refer to anything other than that for which it was cognized.

To say those names are contingent merely because those names were chosen arbitrarily, is nowhere near the logical contingency indicated in epistemological metaphysics. Or, to put it in simplest terms….see how easy it is to force language to screw with reason.
————-

quote="RussellA;767433"]even though I can only know Hesperus and Phosphorus a posteriori[/quote]

That’s not quite right. You can only know of an object in space a posteriori. The object in space is not its name, it is just a thing. The name you know a posteriori because you learned it through experience, as opposed to being the one that installed the name on the object. But to know the object as such, is not to know the name of the object as such, insofar as they are completely different perceptions. You are merely relating the object to the name, which you cannot do a posteriori, but only in reason a priori, yet under a posteriori conditions.

It’s is an empirical fact Phosporus is Venus, and, it is an empirical fact Hesperus is Venus. It is therefore an analytical cognition, hence necessarily true, that Phosporus is Hesperus, in that it is just saying Venus is Venus. — Mww

We're dealing with transitivity: If (a=b) and (b=c) then (a=c). Hence we can agree that
Necessarily [if (a=b) and (b=c) then (a=c)]. I gather something like this is your "analytical cognition".

But we are substituting this into an opaque context - whether they are empirical facts.

In your argument you have:
It’s an empirical fact that (a=b)
It’s an empirical fact that (b=c)
Necessarily [if (a=b) and (b=c) then (a=c)]
Hence necessarily (a=c)

That doesn't work, since the argument changes modality form being empirical to being necessary.

You might suppose that since it's an empirical fact that (a=b), it is not a necessary fact that (a=b). But that would be question-begging, since what is in contention is exactly whether the empirical fact that Hesperus = Phosphorus is a necessary fact. And in any case that would give

It’s not necessary that (a=b)
It’s not necessary that (b=c)
Necessarily [if (a=b) and (b=c) then (a=c)]
Hence necessarily (a=c)

Which doesn't work, either.

In nay case, the contention is not whether Phosphorus is Venus, but whether Phosphorus is Hesperus. That Phosphorus is Hesperus is a discovery made by those observing the night sky. And yet that Phosphorus is Hesperus is a necessary fact.

Another way to set out the issue is that, had it been instead discovered that Hesperus is not Phosphorus, we would not be talking about Venus. One or both of Hesperus or Phosphorus would not have been Venus.

So it seems we are left with empirically discovered necessities.

But it is nevertheless contingent, re: not necessary, that the second planet from the sun is called out by any of the names Venus, Phosporus or Hesperus, such names arbitrarily determined by whoever took it upon himself to assign them. — Mww

This is a seperate point to that dealt with in my previous post. Yes, on this we agree.

“… Secondly, an empirical judgement never exhibits strict and absolute, but only assumed and comparative universality (by induction); therefore, the most we can say is—so far as we have hitherto observed, there is no exception to this or that rule. If, on the other hand, a judgement carries with it strict and absolute universality, that is, admits of no possible exception, it is not derived from experience, but is valid absolutely à priori.…” — Mww

Doesn't this just assert that an empirical judgement is contingent? WHere's the argument?

Knowledge is experience, experience is always changing with time, so knowledge is always changing with time, therefore knowledge is contingent on time. — Mww

Well, we know 4=2+2, but that doesn't change over time... an we know water boils at 100℃, at any given time; that doesn't change. So that doesn't work.

But he’s famous, got letters after his name, might even hold a chair, and I’m none of that, so….. — Mww

I did change that to "there is disagreement between Kant and Kripke", in an attempt to keep us out of court. Refresh issues.

Are we up to the wooden lectern? — frank

Yep.

At the bottom of p. 178, the lectern is picked out using a demonstrative: "Here is a lectern".

Kripke asks if this lectern could have been made of ice. His answer is that it is entirely possible that the lectern before us is made of ice, but that if this were so it would be a different lectern.

(Edited to keep happy)

Kripke asks "could this lectern have been made of ice?" His answer is that it is entirely possible that the lectern before us is made of ice, — Banno

I don't see where he says the lectern before us could be made of ice. I think he's saying it couldn't be.

If I read it right, at least, you're missing the "but that if this were so it would be a different lectern".

So it could be, but then it's not the lectern we're talking about right now.

Why the misquote? You left out "but that if this were so it would be a different lectern".

If one had done so, one would have made, of course, a different object. It would not have been this very lectern, and so one would not have a case in which this very lectern here was made of ice, or was made from water from the Thames. — kripke

Yep.

We might have had before us a different lectern.

I don't see an issue, @frank.

Heh yeah we cross-posted.

Good thread. Got me to try Kripke again.

This is what you wrote:

Kripke asks "could this lectern have been made of ice?" His answer is that it is entirely possible that the lectern before us is made of ice, but that if this were so it would be a different lectern. — Banno

That is incorrect. He doesn't say the lectern before us could be made of ice. You misquoted.

Cheers.


That seems unusually pedantic of you, Frank.

...could this very lectern have been made from the very beginning of its existence from ice, say frozen from water in the Thames? — Kripke

But I wrote that Kripke asks "could this lectern have been made of ice?"

I was wrong. Please forgive me. :roll:

Cheers. — Banno

I realize now I kind of went off on my own tangent in interpreting the whole text, which is different from the intent you've set out. I don't think you mind given the cheers, but I'm just noting it now.

Still reading along with the interpretations, though. Slow lab days these days post holidays :D

Do you have a substantive point to make?

Here's the bit I take to count in our previous coinversation:

Let me therefore emphasize that, although an essential property is (trivially) a property without which an object cannot be a, it by no means follows that the essential. purely qualitative properties of a jointly form a sufficient conditionf or being a, nor that any purely qualitative conditions are sufficient for an object to be a. Further even if necessary and sufficient qualitative conditions for an object to be Nixon may exist, there would still be little justification for the demand for a purely qualitative description of al counterfactual situations. We can ask whether Nixon might have been a Democrat without engaging in these subtleties. — Footnote 13

Do you wish to pursue this topic?

Do you have a substantive point to make? — Banno

I'm not sure why you're getting miffed. I simply pointed out that you misquoted the text.

At this point, that is the substantive point I have to fucking make. OK?