They are different statements though. One is the statement of x, the other is describing something about x. It's the difference between saying dog and saying a dog is a dog. — Artemis

They're both saying the same thing. The latter sentence just says it twice. Redundant.

I recall that during one walk Einstein suddenly stopped, turned to me and asked whether I really believed that the moon exists only when I look at it.

That sounds to me like a rhetorical or incredulous question meant to convey Einstein's opinion that he thinks the moon does exist when it's not looked at.

One is the statement of x, the other is describing something about x. It's the difference between saying dog and saying a dog is a dog. — Artemis

In what English class did you learn that "x=x" or "it is itself" counts as a description of something, and not earn you a detention for being cheeky? This is a misuse of the English word 'description'.

I recall that during one walk Einstein suddenly stopped, turned to me and asked whether I really believed that the moon exists only when I look at it.

That sounds to me like a rhetorical or incredulous question meant to convey Einstein's opinion that he thinks the moon does exist when it's not looked at. — Pfhorrest

The issue is, why Einstein, and why that question. It's related to a point that Jorn Doe picked up on, but is not really related to this thread, so I will not elaborate right now.

I think you've totally missed what I am arguing.

You know that Albert Einstein famously asked that very question. The exact quote is:

"We often discussed his notions on objective reality. I recall that during one walk Einstein suddenly stopped, turned to me and asked whether I really believed that the moon exists only when I look at it."

As recalled by his biographer Abraham Pais.

Why did Einstein, of all people, feel obliged to ask that question? — Wayfarer

Because he thought Pais was nuts. Anyway, physicist David Mermin has since resolved the question to everyone's satisfaction. :-)

The questions with which Einstein attacked the quantum theory do have answers; but they are not the answers Einstein expected them to have. We now know that the moon is demonstrably not there when nobody looks. — Boojums All the Way Through - N. David Mermin

Thanks. That was the rhetorical point I was working towards.

Actually in that reference you give, Pauli says, ironically, that one should no more rack one’s brains about whether something one cannot know exists at all times, than with the ancient question of how many angels might dance on the head of a needle. I happened upon the origin of this aphorism, which is routinely invoked to ridicule medieval philosophy. I found that the original form of the question was simply whether two immaterial intelligences (angels) could occupy the same location, as presumably they have no spatial extension. Which is not really such a daft question, given belief in angels; and also strangely suggestive of the whole issue of the ontology of a ‘super-position’!

Pure and unapplied logic makes no empirical claims and only expresses linguistic rules for rewriting a term. All logically valid sentences are reducible via rules of term-rewriting to "X=X", where the equality sign designates the term on the left hand side to be an abbreviation of the term on the right-hand side.

If in the course of reducing a logical expression one obtained the opposite, all this would mean is that one's use of terminology isn't consistent. The solution is either a wholesale adjustment of the axioms that defines one's terminology, or to forbid on a case-by-base basis any derivation that leads to contradiction. For example, if Peano arithmetic was discovered to be accidentally inconsistent, a possible solution is to retain it's rewriting axioms for arithmetic, but to forbid any derivation beyond a certain size.

Philosophers have an unfortunate tendency to mistake ordinary uses of equality as denoting a physical relation between things rather than as being a linguistic relation between terms. For example, if the word "Now" is considered to refer to presently moving objects we arrive at the Hegelian contradiction "Now isn't now". But all this means is that our definition of 'now' is inconsistent. The contradiction is removed by replacing each and every use of "now" with a unique and new term, such that we are never tempted into equivocating one "now" with another.

Philosophers have an unfortunate tendency to mistake ordinary uses of equality as denoting a physical relation between things rather than as being a linguistic relation between terms. — sime

This is why "x=x" is not a good way to express the law of identity. It really doesn't serve that purpose.

Then make a better argument.

:up:

In what English class did you learn that "x=x" or "it is itself" counts as a description of something, and not earn you a detention for being cheeky? This is a misuse of the English word 'description — StreetlightX

Maybe if you have a bad teacher, but think you just don't fully understand the word "description."

They're both saying the same thing. The latter sentence just says it twice. Redundant. — Harry Hindu

One is saying x and the other is saying something about x.

Maybe if you have a bad teacher, but think you just don't fully understand the word "description." — Artemis

No seriously - if someone says: "describe this dog to me", and you reply "it's a dog", there are a few possibilities - you misheard the question; you were being cheeky; its so obvious what the dog looks like that it'd be redundant to describe it any further; you don't understand English; you're unacquainted with the dog so are unable to elaborate. What you have not done, is give a description of the dog.

Thanks. That was the rhetorical point I was working towards. — Wayfarer

Yes, as you know, Mermin was referring to Bell's Theorem which shows that the predictions of quantum mechanics are inconsistent with local realism (where realism, in the sense used here, refers to counterfactual definiteness - the ability to speak "meaningfully" of the definiteness of the results of measurements that have not been performed).

Actually in that reference you give, Pauli says, ironically, that one should no more rack one’s brains about whether something one cannot know exists at all times, than with the ancient question of how many angels might dance on the head of a needle. — Wayfarer

If we reframe the question to be about photons instead of angels, it turns out an unlimited number can because particles with integer spin, such as photons, are not subject to the Pauli exclusion principle. :-)

Particles with an integer spin, or bosons, are not subject to the Pauli exclusion principle: any number of identical bosons can occupy the same quantum state, as with, for instance, photons produced by a laser or atoms in a Bose–Einstein condensate. — Pauli exclusion principle

Well, glad we sorted that out!

It doesn't describe anything because it presents no information. You could have zero knowledge of what "x" is and still agree that x = x. That can't be called describing anything.

No seriously - if someone says: "describe this dog to me", and you reply "it's a dog", there are a few possibilities - you misheard the question; you were being cheeky; its so obvious what the dog looks like that it'd be redundant to describe it any further; you don't understand English; you're unacquainted with the dog so are unable to elaborate. What you have not done, is give a description of the dog. — StreetlightX

It doesn't describe anything because it presents no information. You could have zero knowledge of what "x" is and still agree that x = x. That can't be called describing anything. — Saphsin

While x=x is almost always not a satisfactory answer to the question "what is x?" in most circumstances of non-philosophical discussion, it does tell us more about x than simply stating "x" would. It tells us that x is self-identical. Self-identical is an attribute. That it happens to be an attribute all things in the universe share makes it no less an attribute. Thus, calling attention to said attribute is, by any definition of description of which I know, a description.

I'm in agreement with you both that it's not even a very interesting attribute in most cases of any practical matter. It's important, though, that we know that x=x is an attribute all things share, because that's where formal logic starts. If you go through a formal proof which says otherwise, i.e. x=~x, you're in trouble.

Self-identical is an attribute. That it happens to be an attribute all things in the universe share makes it no less an attribute. — Artemis

This seems like linguistic sommersaults to me. A distinction without a difference for no purpose.

This seems like linguistic sommersaults to me. A distinction without a difference for no purpose. — StreetlightX

Except if you want a foundation for formal logic :)

Logic describes nothing. And translating predicates as 'attributes' is unmotivated and contentious.

Logic describes nothing. And translating predicates as 'attributes' is unmotivated and contentious. — StreetlightX

Well, wrong and wrong, but I guess at this point all is left is to agree to disagree. :chin:

The arrogation of logical terms into metaphysical posulates is a cardinal sin for which philosophers ought be be expelled from the academy for.

The arrogation of logical terms into metaphysical posulates is a cardinal sin for which philosophers ought be be expelled from the academy for. — StreetlightX

Cool story bro.

*shrug* I'm not the one who doesn't know English.

*shrug* I'm not the one who doesn't know English. — StreetlightX

Um....:

for which philosophers ought be be expelled from the academy for. — StreetlightX

Okay then.

Ah right, now to make a grammatical abberation philosophical: "to be be, or to not be be?; that is the question".

:snicker:

One is saying x and the other is saying something about x — Artemis

Yes, saying something redundant about x.

X is a symbol and symbols are already about something. A symbol can't be about itself. Then its not a symbol, but the thing itself.

"Artemis" is a string of symbols that is about something that isn't a string of symbols. It is about what it is to be Artemis. "Name" is a string of symbols that is about the string of symbols, Artemis, not about what it is to be Artemis.

We now know that the moon is demonstrably not there when nobody looks. — Boojums All the Way Through - N. David Mermin

The movie, The Time Machine, taken from Wells' novel, shows the moon that is not there breaking apart in a catastrophic sequence, which, apparently, is not there as well. :scream: