• Banno
    25.3k
    So to p.167 and the case of proper names.

    If we substitute a and b for x and y, with a few more brackets to explicate the scope, we have

    and derive


    And so to the consequences of this derivation. Quine argues, roughly, that the fact that Hesperus is Phosphorus was discovered, and so is contingent. That Guarisanka was discovered to be Everest - I checked this with Nepalese friends, and it is indeed incorrect, they are distinct mountains -
    and so on. The suposition here is that an identity that we discover cannot be a necessary identity, and so there must be something amiss with the derivation (1-4).
  • Banno
    25.3k
    Sure. The answer, at least for modal issues, is to drop talk of de re and de dicto and use diamonds and boxes and brackets to keep the scope explicit.

    Many problems occur as a result of using a nomenclature form the 1200's. So don't.
  • Shawn
    13.3k
    Sure. The answer, at least for modal issues, is to drop talk of de re and de dicto and use diamonds and boxes and brackets to keep the scope explicit.Banno

    I'm not sure everyone knows that. But just to clarify we usually appeal to de dicto (from our world) and then stipulate a de re about Superman in a possible world, as a counterpart or counterfactual from the world where we came to know about him.

    Just wanted to make sure we're quantifying correctly here about Superman's identity obtaining even from de re modalities, with respect to de dicto knowledge we have about him in our world.

    Thanks.
  • Banno
    25.3k
    ...we usually appeal to de dicto (from our world) and then stipulate a de re about Superman in a possible world, as a counterpart or counterfactual from the world where we came to know about him.Shawn

    So can you phrase that in terms of boxes and diamonds?

    And if you can't, do you actually understand it? OR are you sliding along an ambiguity?
  • Banno
    25.3k
    My thread. I'm the mahout. I have the cool hat, and a thotti, in a hopeless attempt to keep control.
  • frank
    16k

    Let go of fixed plans and concepts, and the world will govern itself. (Tao Te Ching, 57)
    :nerd:
  • Banno
    25.3k
    And so to the deconstruction of Russell from p.169.

    Russell tried to achieve some semblance of certainty by supposing that the only real names were "this" and "that", and what otherwise appears to be a proper name is actually a description.

    It wasn't all that successful; things got complicated.

    Russell would have had us use only predicate such as f,g,h..., and individual variables, x,y,z..., but not individual constants, a,b,c... Russell worked out a way to replace proper names with definite descriptions - a definite description being a sequence that serves to pick out exactly one individual. Importantly, he did this using an identity statement, so opening himself up to the sort of modal considerations we have before us.
  • RogueAI
    2.9k
    Kripke, at a very young age, developed a formal semantics for modal logic, presenting a completeness theorem.Banno

    Anecdote: I took philosophy at UCLA and had Donald Kalish as my logic professor. He told an interesting story about how he and a partner were all ready to give a talk on a paper on logic only to find out this 16 year old kid, Kripke, had beaten them to the punch.
  • Shawn
    13.3k
    So can you phrase that in terms of boxes and diamonds?Banno

    Nope.
  • Banno
    25.3k
    One of my old profs tells a story of giving a talk in which some young kid tried to ask a question which the prof idly dismissed. One of the others in the audience began "I think what Professor Kripke is asking is...."

    Nope.Shawn

    Thought not.
  • Hanover
    13k
    I think you at least have to have a common origin for all the possible versions of you. Like could you have been born female?frank

    A replica of me, but for being female, would still be a Hanover, I think.

    It's a ship of Theseus sort of question. Which board is essential to maintain identity? A transsexual would not claim loss of essential identity upon change of gender. Interestingly, they'd claim not just maintenance of identity upon transition, but would claim that the removal of those boards (so to speak) was their way of purifying their identity.

    Your example was a loaded one, so perhaps another example would work better.

    What I can say is that there is but one world with a Hanover where Hanover is defined as the one living in this world, and it would do you no good to search for Hanovers in other worlds because each one you find will not be a Hanover by definition.

    There are no worlds with all white penguins where penguins are defined as being partially black. If you drop the necessity of identifying them as partially black, there will be white ones in some possible world.

    But this is obvious and not interesting, so where have I missed something?
  • Metaphysician Undercover
    13.2k
    How can an object such as an apple, having a self-identity, have infinite possibilities ?RussellA

    The identity is within the object itself (as the law of identity states, it is the same as itself). The object's identity appears to any one of us as infinite possibilities because I can name it whatever I want.

    “For every property F…..” F can be any property, such that if F belongs to x, and if x is identical to y then it is necessary that F belong to y. If F is the property of being round, and if x is round and y is identical to x, then y is round. That’s fine, in that x is, e.g., a round cue ball and y is, e.g., an identically round baseball. Which is also fine, insofar as the conditional is “for any two objects”, satisfied by one cue ball and one baseball.

    It remains that a cue ball is not a baseball. But if x is to stand as identical to y, one of every property F is obviously not sufficient to cause x to be identical to y because of F. So keep adding F’s to x, maybe hundreds of F’s, such that when those properties also belong to y, they become closer and closer to both x and y being either a cue ball or a baseball. Still satisfies “for any two objects”, as well as for any property F which belongs to x also belongs to y.

    The kicker: “For every property F….”, in order for the cue ball x and the baseball y to be identical, every property F must belong to both equally. It follows that in order for x to be identical to y, a space F belonging to x is the same space F belonging to y, and x and y simultaneously be commonly imbued with every other possible F equally. But two objects sharing the same space F is a contradiction, which negates the case. It must be, then, that they occupy different space F’s but still be commonly imbued with every other F equally. How does that happen, you ask….surely with bated breath. Well…..the space of x in one world, and the space of y in another world. What else?????
    Mww

    Well, this does little for me. I'd rather stick to the Leibniz principle, and hold the belief that if any true statement made about x is also true about y, they are really one and the same thing. Then it's a mistake to talk about what "x" and what "y" refer to as if it were two different things, because it's really one and the same thing. To say that they each exist in a different space in a different world doesn't do it for me, because that is actually saying something different about each of them.

    Hence contingent identity, contingent on the possibility of other worlds. Under the assumption of another merely possible world, however, such world can only have possible space, from which follows only a possible y can have the property of possible space, or, more correctly, only a possible y can occupy a possible space possibly, which reduces to a real x being identical to a possible y, which is not the original argument. In effect, then, in order to assume x = y identity necessarily, mandates a veritable maze of contingent possibilities.

    And that’s a category mistake. Dunno if it’s yours or not, but it works, doesn’t it? The article goes on to circumvent these mistakes, re: “let us use necessity weakly”, or actually, to deny them altogether, re: “I will not go into this particular form of subtlety** here because it isn’t relevant”, in order to justify the notions contained further on in it.
    Mww

    Yes, I'd say that's a good description of the category mistake involved, it annihilates the separation between possible and actual. It's actually a very similar error to one which is common in mathematical axioms, especially ones which deal with infinity. You'll see for instance that a "countable set" is one which can be counted using the natural numbers. But the natural numbers are not actually countable, being infinite. So they take the true defining feature of the natural numbers (impossible to count, by definition of "infinite"), and replace it with a different defining feature (logically possible to count), and come up with "countable".

    But still, if a theory starts out illogically, and if the circumventions are not all that valid, wouldn’t it jeopardize the whole? Kripke is just saying, if it was this way, we could say this about it. But if it couldn’t be this way, why still talk as if it could? He goes on to talk about it in a different way, that’s all.
    (** existence as a predicate, reflecting on existence in possible worlds)
    Mww

    That is the weird and wonderful reality of the world we live in. We still go on to talk about it simply because it is possible to talk about it. Ultimately, this ought to become the central point, the reality that It is possible to say things which are completely untrue, and still have people make a very good understanding of what you have said.

    So, what are they actually understanding in this situation, we might ask. When someone has a very clear and accurate understanding of something which is false, we can't say it's a misunderstanding, because they actually do understand. What is it that is understood then? What is the subject matter of falsity? Is it "possibility"? In a way, it must be, because the only way to give reality to possibility is to annihilate the reality of truth, and that seems to leave us with falsity. The only remedy, if we desire to push forward in this vein of understanding nothing (which can't be called misunderstanding) is to equally annihilate falsity, leaving us with something like a model-dependent realism. But this means we must completely deny identity, so it requires an ontology similar to dialectical materialism.
  • frank
    16k
    What I can say is that there is but one world with a Hanover where Hanover is defined as the one living in this world, and it would do you no good to search for Hanovers in other worlds because each one you find will not be a Hanover by definition.Hanover

    And this is the problem Kripke is addressing. If your identity is a description or definition, then it makes no sense to say you could have become a plumber.

    But we can say that. There's a possible world where you're a plumber, so it doesn't look like your identity can't be a description. So what is it?
  • RussellA
    1.8k
    And this is the problem Kripke is addressing. If your identity is a description or definition, then it makes no sense to say you could have become a plumber. But we can say that. There's a possible world where you're a plumber, so it doesn't look like your identity can't be a description. So what is it?frank

    That John does some plumbing work is not part of his identity, in that neither is holidaying in Paris for ten days part of his identity.

    Russell says that the name John is a description rather than a reference.

    We can say "John is in Paris", "John is a barber", "John could running for the bus" or "John could be a plumber".

    I am not defined as a person by where I live or what I do. The fact that John is in Paris, is doing some barbering work, running for the bus or doing some plumbing work is not part of his identity, and therefore not part of the name John, is not part of what the name John describes.

    The sentence "John is a barber" illustrates the metaphorical aspect of language. John's identity is not that of being a barber, in that water is H2O, it means "John is doing some barbering work".

    As the fact that John is in Paris is not part of the description of John's identity, John could equally well be in Rome. As the fact that John is doing some barbering work is not part of the description of John's identity, John could equally well be doing some plumbing work.
  • frank
    16k
    Russell says that the name John is a description rather than a reference.RussellA

    The first part of this essay explains why that's problematic. How do you respond to Kripke's point?
  • Metaphysician Undercover
    13.2k
    If your identity is a description or definition, then it makes no sense to say you could have become a plumber.frank

    By the law of identity, a thing's identity is the thing itself. To say that a thing's identity is a description, definition, or even a name, is to make the category mistake of saying that the thing's identity is what someone says about the thing, rather than the thing itself. The name of a thing is a representation of the thing's identity, not its identity.

    If you allow this category mistake into your thinking, then you allow for all sorts of sophistry to invade your mind, such as the questions about Hesperus and Phosphorus, and the ship of Theseus. Instead, we ought to be content in knowing that we simply cannot make any true identity statements, and that's just a basic feature of human knowledge.
  • frank
    16k
    Instead, we ought to be content in knowing that we simply cannot make any true identity statements,Metaphysician Undercover

    What's an identity statement?
  • Metaphysician Undercover
    13.2k
    What's an identity statement?frank

    As used in that post, any statement which claims to reference the identity of an object. Our only access to an object's identity is through the object itself, so we reference the object itself, and we might do this with a name. If we claim to reference the object's identity, and then proceed to make statements about the object's identity as if it were something separate from the object, we enter the fantasy world of sophistry. There really is no such thing, so if we insist that there is, it could be absolutely anything, so sophistry runs amuck.

    Here's an example of such a sophistic reference intended to create an independent, or separate identity:

    The suposition here is that an identity that we discover cannot be a necessary identity, and so there must be something amiss with the derivation (1-4).Banno

    See what happens? At the first attempt to create such an independent identity, immediately it is evident that something is "amiss". That's because the thing itself with its true identity is understood as independent, so it appears like it's identity must be "discovered", but whenever we try to talk about a separate identity, this must be something created by us.

    If we allow the "discovered" identity, we allow Platonism, as separate, independent Forms which are discovered. If we allow a created identity, then we reject the true identity within the thing, as inconsistent with the created identity, and we have a type of anti-realism. The only solution is to deny a separate identity altogether, to establish a ground free from such sophistry.
  • frank
    16k
    That's because the thing itself with its true identity is understood as independent, so it appears like it's identity must be "discovered"Metaphysician Undercover

    I think you misunderstood what he meant by discovering identity. It appears that a lot of the time identity is something we declare. That's what's happening when a baby is baptized by the Catholic Church. The baby is henceforth identified by that name.

    There are other ways to identify that kid, though. I would tell the police that he has a mole on his knee.

    In Spanish there are two different words for predication. One signifies identity: things that don't change. The other signifies passing states (although it's not always cut and dried, but that's the basic idea.)

    That's one reason we shouldn't get carried away with philosophizing by the way people speak. Different languages are structured differently and so would produce different philosophies.
  • Mww
    4.9k
    I'd rather stick to the Leibniz principle, and hold the belief that if any true statement made about x is also true about y, they are really one and the same thing.Metaphysician Undercover

    I covered that, and probably best to leave it at the same kind of thing.
  • RussellA
    1.8k
    The first part of this essay explains why that's problematic. How do you respond to Kripke's point?frank

    Proper names refer to descriptions.

    I wrote: "As the fact that John is in Paris is not part of the description of John's identity, John could equally well be in Rome. As the fact that John is doing some barbering work is not part of the description of John's identity, John could equally well be doing some plumbing work."

    The Ancient Greeks saw in the evening something having the properties brightest natural object in sky, visible by naked eye during day, has no rings and tagged it Hesperus. They also in the morning something having the properties brightest natural object in sky, visible by naked eye during day, has no rings and tagged it Phosphorus. Pythagoras recognized that Hesperus and Phosphorus were in fact the same object, the planet Venus.

    Kripke wrote: 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, and not because the proper names were descriptions.”

    Does the name Hesperus refer to Venus or describe its properties brightest natural object in sky, visible by naked eye during day, has no rings, appears in evening?

    If Hesperus refers to Venus, does Venus refer to Venus or describe its properties brightest natural object in sky, visible by naked eye during day, has no rings, appears first in the morning and then in the evening?

    Venus cannot exist independently of its properties, in that if Venus had no properties, Venus wouldn't exist. If I looked into the sky and saw no properties I would see no Venus. As Venus would not exist if it had no properties, Venus cannot refer to Venus but can only describe its properties. Venus cannot create itself by referring to itself.

    IE, the proper names Hesperus and Phosphorus are descriptions, as in Russell's Descriptivism.
  • RussellA
    1.8k
    The identity is within the object itself (as the law of identity states, it is the same as itself). The object's identity appears to any one of us as infinite possibilities because I can name it whatever I want.Metaphysician Undercover

    Does a single object as a thing in itself have infinite possibilities, or do we, as observers, see infinite possibilities in a single object ?
  • RussellA
    1.8k
    The suposition here is that an identity that we discover cannot be a necessary identity, and so there must be something amiss with the derivation (1-4).Banno

    I don't understand the logic of (1)

    Kripke wrote: "for any objects x and y, if x is identical to y, then if x has a certain property F, so does y"

    The sequence of (1) is:
    A) starting with object x which has property F
    B) knowing that object x is identical to object y
    C) I then know that object y has the same property F as x

    My supposition is that i) if there are no properties, then there is no object ii) if I cannot see any properties, then I cannot see any object.

    However, this sequence seems more logical:
    A) As object x has property F, I can know object x
    B) I can only compare object x with object y if I know object y, and I can only know object y by knowing its property G. Therefore, I must know object y's property G before being able to compare object y to object x. If I didn't know object y's property, I wouldn't know that object y existed.
    C) When comparing object x and its property F with object y and its property G, in discovering that property F is identical with property G, I then know that object x is identical to object y

    IE, the problem with (1) is how can I know object x is identical to object y before I know object y's property?

    Am I missing something.
  • Shawn
    13.3k
    Thought not.Banno

    And if you can't, do you actually understand it? OR are you sliding along an ambiguity?Banno

    Even though I can't formalize my statement. I believe I understand it. :smile:
  • Banno
    25.3k
    I know what I want to say but I can't find the right words...

    Happy with this thread so far? The folk who really need to read the article have just voiced their opinions, again, without addressing, and probably without even reading, the article.

    Anyway...
  • Shawn
    13.3k
    Happy with this thread so far?Banno

    Not really. I already said what I thought worth mentioning.

    The folk who really need to read the article have just voiced their opinions, again, without addressing, and probably without even reading, the article.Banno

    I tried, you tried. There's nothing more to address here. I consider the thread finished before we even started.
  • Jamal
    9.8k
    I've been watching this and I've deleted a couple of posts by people who haven't addressed the article or who clearly haven't read it, but my skill in identifying them is limited to the obvious ones. Therefore, folks shouldn't hesitate to report off-topic posts.
  • Banno
    25.3k
    ...further examples follow. Heat, consciousness, the chemical structure of water, all interesting in their own right, all related by their connection with identity and necessity.

    We've seen in the posts hereabouts the tendency to jump to trying to solve the problem before one works out the logic involved, before considering the way language works here.

    cylindershadows.jpeg
  • Banno
    25.3k
    On p.171 Kripke tells us what his conclusion is. That's right - the text up until now is only setting up the issue to be addressed, here's the answer, and the remainder of the paper, the two-thirds that is left, is the arguments in support of that conclusion.

    If identity statements are true, then they are necessarily true.

    Now I agree with him, because I find the argument that follow convincing. I think he presents a way of talking about necessity and identity that allows us to do so in a way that is coherent and consistent, and that the alternatives do not give us the same clarity.

    Those with the patience to follow the discussion might agree or disagree, but what they have to say will be of more value than the views of those who lack such patience.
  • Banno
    25.3k
    And so to the distinction between rigid and nonrigid designators. A rigid designator picks out the very same individual in every possible world in which that individual exists. A nonrigid designator doesn't.

    Examples: "Benjamin Franklin" picks out the same individual in any possible world, but "the inventor of bifocals" doesn't. Someone else, not Ben Franklin, might have invented bifocals.

    Of course, Franklin may have had some other name, or someone else might have been called "Ben Franklin". But notice that "Ben Franklin might have had another name" is a sentence about Ben Franklin. The rigid designator still works, And "someone else might have been named 'Ben Franklin'" is not about Ben Franklin, but about his name. Again, the rigid designator still works.

    And here we can see one way to weaponise this account. Ask who "Ben Franklin might have had another name" is about. It appears to be a sentence about Ben Franklin. That is, the Ben Franklin with whom we are familiar and the Ben Franklin who might have had a different name are the very same individual. In particular, it does not seem to be about someone else, Franklin's counterpart in some other possible world.

    This is directed at many of the post hereabouts, but I've jumped ahead, to Lewis. Back to the text.
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