After all, when I say that Adam is Mr. Smith, I don't mean that Adam has identical height to Mr. Smith, or something like that -- no, I mean numerically they are the very same guy. — The Great Whatever

But you don't 'just' mean that 'they are the same guy'; you 'also mean' that they will respond to the same name, that Mr. Jones is responsible for the Bad Thing you thought someone else was responsible for, etc, etc. The phrase 'they are the same guy' is a kind of nominal 'condensation' or short hand of these 'existential ramifications' as it were. What I'm trying to do is reverse the order by which we understand what it means to 'be the same guy'. Mr. Jones is Alan not because he is 'the same guy'; he is 'the same guy' because Alan has done everything Mr. Jones has, because he will (probably) respond the same whether he is called Mr. Alan or Jones, etc. That Mr. Jones and Alan 'are the same guy' (=identical) is just a way of saying that. Identity is parasitic, derivative, of these things which have nothing to do with identity 'in themselves'.

But you don't 'just' mean that 'they are the same guy'; you 'also mean' that they will respond to the same name, that Mr. Jones is responsible for the Bad Thing you thought someone else was responsible for, etc, etc. — StreetlightX

I don't think I mean any of those things. That might be implied depending on the situation, sure. But that's not what the sentence means. For example, it's possible for Adam to be Mr. Smith, but not respond to both those names.

Not at all. I didn't have this name until I made it up for online fora, but I was still myself. — The Great Whatever

Just goes to show that TGW is merely a part of you, the online you, TGW is you in a similar sense that the spout of the kettle is the kettle.

When the same individual is denoted by two names that have two distinct Fregean senses, then, upon learning that they are identical, what is learned by a language user who was acquainted with this individual under those two distinct modes of presentation isn't merely a fact about language. As Kripke has shown, in a clear sense, the fact about language is contingent but the identity statement that has been learned about is necessary. (Kripke, though, thought that he was arguing against a Fregean conception of proper names. Gareth Evans has shown that Kripke's observations are consistent with a Fregean account of singular senses, understood non-descriptively.)

For instance Lois Lane may be acquainted both with Superman and with Clark Kent, and know them respectively as "Superman" and as "Clark Kent". When she eventually learns that Clark Kent is Superman she doesn't merely learn a fact about linguistic use -- (although, as TGW hinted, she could learn this fact inferentially through learning another fact about linguistic use). She rather learns the fact that Superman and Clark Kent are the same individual, a fact that no alternative (i.e. counterfactual) conventions of linguistic use could have negated. — Pierre-Normand

Fair point. I should have said something to learn identity is to at least learn a fact about linguistic use, etc. In any case, the point is to resolve identity into a context, to show that identity is never brute, but always relational. To learn that Superman and CK are the same is to learn they both saved that cat from the tree, that they both are excellent at changing clothes very quickly, etc.

Another issue that has been raised in the recent exchanges in this thread is the identity that a material object (i.e. a "substance", or "spatiotemporal continuant") retains with itself through material and/or qualitative change, through time. This issue is related to the first since an object can be encountered at two different times under two different modes of presentation (i.e. while being thought about under the two different Fregean senses of "A" and "B" successively, such that the numerical identity of their denotata may come under question). What settles the question of the identity of A with B are the criteria of persistance and individuation for object of this sort, and the spatiotemporal carrer(s) of the relevant object(s): both things that may be matters of empirical investigation. — Pierre-Normand

But to say all of this is already to subscribe to a very specific kind of metaphysics which is everywhere fraught with problems I think. Part of my line of questioning here is to call into question exactly these sorts of pressuppositions that thinking in terms of formal logic encourage, I think.

Just goes to show that TGW is merely a part of you, the online you, TGW is you in a similar sense that the spout of the kettle is the kettle. — John

I don't think there is an online me. Yes, I go online, but that doesn't mean there are multiples of me, or something like that, just that sometimes the same person -- me -- is online, sometimes not. Someone could use the name TGW to refer to me offline, and not in respect to any online capacity. It just so happens that one of my names is used more often in an online capacity because that's where it was introduced and circulated.

I don't think I mean any of those things. That might be implied depending on the situation, sure. But that's not what the sentence means. For example, it's possible for Adam to be Mr. Smith, but not respond to both those names. — The Great Whatever

Ugh, I missed the qualification of 'probably' that I had meant to attach to that (I did the second time I mentioned in it my post!). Not that it matters though: the point remains the same. To assert that Alan is Mr. Smith only makes sense if there is some kind of significance attached to that designation. It may not be that they will respond to the same name, but it will be - of necessity - some (contingent?) fact.

But isn't this only saying that identity statements of this sort generally have communicative functions that they're put to?

Surely this is compatible with the more basic point I'm trying to make, which is that your two earlier assertions:

(1) that people don't say a thing is identical to itself in ordinary speech, and
(2) to say that a thing is identical to itself is nonsensical

are wrong?

Indeed it seems to admit that when doing such an identification, some other fact is motivating it, is to presuppose that such identifications take place, make sense, and are an ordinary part of linguistic usage.

Fair point. I should have said something to learn identity is to at least learn a fact about linguistic use, etc. In any case, the point is to resolve identity into a context, to show that identity is never brute, but always relational. — StreetlightX

I am not entirely sure about that last point. Regarding the first, linguistic use need not be at issue. Lois Lane may have seen a man flying in the sky, later seen a man in her office, not know their names at all, and yet wondered whether she saw the same man twice. In that case, even though her two episodes of demonstrative reference (in thought) could have been (unbeknownst to her) correlated with the extent linguistic uses of "Superman" and "Clark Kent", or could have served to anchor new linguistic uses -- if, e.g. she would report upon her encounters using made up pseudonyms -- what she wonders about is if the man whom she encountered on one occasion is the man whom she encountered on another occasion.

Regarding the metaphysical issues that you believe to be contentious (regarding substances), I don't think we can make the economy of them since there can't be so much as a thinkable singular Fregean sense (i.e. demonstrative reference to an empirical particular) *or* a well defined naming practice if one is agnostic regarding the persistence through qualitative/material change of individuals encountered in experience at different occasions. (This is, incidentally, the topic of Kant's Analogies of Experience, brilliantly discussed by Sebastian Rödl, in connection with the metaphysics of substance, in his Categories of the Temporal: An Inquiry into the Forms of the Finite Intellect, HUP, 2012)

Although I have been mainly agreeing with TGW against StreetlightX, there may be a sense in which I agree with StreetlightX's Wittgensteinian point about the essential relationality of identity statements. On the neo-Fregean account of truth and meaning that I am working with (following Evans and McDowell) facts of the world are true Fregean propositions rather than true Russellian propositions.

Hence the proposition expressed by "Hesperus is Phosphorus", say, where the two names have different Fregean senses, does *not* express the same proposition (and hence doesn't make the same empirical claim) as does the sentence "Hesperus is Hesperus", even though both sentences express the same Russellian proposition.

It is, however, a somewhat contentious Wittgensteinian point that the latter assertion is nonsense. For sure, it doesn't have much of a use in ordinary language; and likewise for the utterances of Moore-paradoxical statements, which can nevertheless express meaningful and true propositions, and likewise for a variety of truisms that Wittgenstein notoriously thought nonsensical for one to assert or claim knowledge of.

Surely this is compatible with the more basic point I'm trying to make, which is that your two earlier assertions:

(1) that people don't say a thing is identical to itself in ordinary speech, and
(2) to say that a thing is identical to itself is nonsensical — The Great Whatever

(1) People don't say a thing is identical to itself in ordinary speech [in isolation from some sort of parameter which would make sense of such an identity claim].
(2) To say that a thing is identical to itself [in the absence of some sort of context] is nonsensical.

(2) To say that a thing is identical to itself [in the absence of some sort of context] is nonsensical. — StreetlightX

Why not simply say that it is known a priori to be necessarily true and hence uninformative? What makes it known to be necessarily true, though, is a function of the meanings (Fregean references) of the words used to make the claim. Hence, even if it is "nonsensical", it is not thereby meaningless; it is, after all, truth-evaluable.

(1) People don't say a thing is identical to itself in ordinary speech [in isolation from some sort of parameter which would make sense of such an identity claim].
(2) To say that a thing is identical to itself [in the absence of some sort of context] is nonsensical. — StreetlightX

Okay, even accepting these are true, this just seems like goalpost-shifting. I never said that to say something is identical to itself is nonsensical in the absence of some sort of context. That's true about pretty much anything (though I'd prefer to say it might serve no communicativ function outside of a context, not that it's 'nonsensical'). As for 'parameters,' you still haven't clarified what those are, and Wittgenstein's claim seems not to make that proviso.

Well, the thing is really a matter of interpretation; there simply is no determinate truth about whether TGW is your whole identity or merely your online identity. And that's the issue I have with AP in general. It may be valuable as a practice if it reveals and clarifies some unnoticed conceptual confusions in our thinking, but it fails to deliver any startling new insights.

None of your arguments have convinced me that "X is identical to X" tells us anything more than "X is X" or even simply "X is".

This is made clearer in Wittgenstein's elaborations in the Investigations: "'A thing is identical with itself" - there is no finer example of a useless proposition, which yet is connected with a certain play of the imagination. — StreetlightX

As I indicated in the other thread, there are two distinct forms of identity. Wittgenstein (intentionally I believe) creates ambiguity with his use of "identity" and "same", inviting the reader to make an equivocal interpretation.

The reason for Aristotle's principle of identity, that a thing is identical to itself, is to place the identity of the thing within the thing itself, rather than the identity which is given to it by human beings who say what the thing is. This move allows for the mistaken identity which arises from human mistakes. Without allowing that there is an identity within the thing itself, independent of what human beings might say about that thing, then there is no possibility that when all living human beings agree, that such is what X is, this could be wrong. So for instance, if in Aristotle's time, human beings agreed that the sun is a body which circles around the earth, this is the identity which the sun has. Without allowing that there is an identity within the thing itself, independent from how it is identified by humans, how could this be wrong?

Hence, even if it is "nonsensical", it is not thereby meaningless; it is, after all, truth-evaluable. — Pierre-Normand

I read 'nonsensical' as 'lacking in sense' in this kind of context. It consists in lacking in any reference to anything that may be perceived. Relations to others have sense, relation to self has no sense; it is not metaphysically robust; and is thus 'lacking in sense' or 'non-sense'. Such things are not meaningless; they find their meaning in formal elaborations of rules. If I am, then it follows that I am myself, and it follows that I am identical to myself, and so on; everyone knows what it means ,but all this kind of elaboration really seems to tell us nothing beyond how rules may be tautologically elaborated.

Relations to others have sense, relation to self has no sense; it is not metaphysically robust; and is thus 'lacking in sense' or 'non-sense'. — John

Surely there is sense in a relation of self to self. I can relate myself of today to myself of yesterday, and my potential self of tomorrow. By establishing these relationships we learn how to better ourselves. And this is very important.

Sure, but I would count that kind of relation, whether logical or material, as being between a part of yourself and another part. There is also, for example, a relation between the whole of yourself and what you are right now, insofar as the former has given rise to the latter.

I don't think so. I think that the whole of myself exists today, and the whole of myself existed yesterday, and the day before. I don't think of the self of yesterday, and the self of today as just parts of myself, otherwise I couldn't call these occurrences occurrences of myself, I'd have to call them parts of myself.

And that denies material identity. There is no longer the temporal continuity of a thing extended in time. There is one part at one moment, another part at the next moment, etc.. We no longer have the identity of the thing itself, with a temporal extension, only different parts related to each other .

Yes, but the whole of yourself is greater, more comprehensive, than it was yesterday (hopefully). It depends on what you mean by 'whole' though; on one interpretation the self at any moment is not the whole self, because some of what has been that self may no longer be present. Memories can be forgotten, senses and limbs may be lost. And it is not as if the totality of your experience, which constitutes the totality of what you have been, is present all at once in any moment. What you are now is the whole of yourself in the sense that it is the culmination of everything you have ever experienced and thought, not in the sense that it is the living presence of everything you have ever experienced and thought.

In another sense, consistent with what you said earlier about material identities having temporal duration. the totality of yourself, your total identity, is spread across time. Looked at that way, no momentary instantiation of your self is your whole self at all. What happened to you today is not part of the total self that you were yesterday, for example; so logically the two total selfs cannot be identical.

Pot calling kettle black. — Wayfarer

That was my first thought as well.

I think this is very interesting! And such great answers, though some of them seem to prove Dennett's point. Philosophy tends to wander off into fantastic speculation or purely technical and theoretical abracadabra. I think what Dennett is saying is that when philosophy starts making claims about ultimate truth it gets a little pretentious. There seems to be only mystery. It is from a standpoint of not-knowing that in my opinion the best philosophies are written. It is from a standpoint of wanting to be right that philosophers become like children in a sandbox.

The most valuable things are the least useful. Useful things possess mainly derivative value. — Pierre-Normand

I'd say that valuing things, finding things interesting, finding things entertaining, etc., is itself useful, plus it has upshot benefits for mental and other physical health--stress, depression, etc. are not good for you.