The Law of Identity

[Logik]

But "LeftJane is LeftJane' is true.

I have no idea why you need to re-affirm this, or what it means for it to be true.
I say LeftJane is LeftJane is false. What then? This whole line of reasoning is nonsense.

You have recognized that you are dealing with two distinct things (two Janes) so you have created a taxonomy of LeftJane and RightJane. 2 variables.
If there was only one Jane, then you would created a taxonomy of: Jane. 1 variable.

The law of identity is about figuring out how many variables you are tracking.

If LeftJane is just RightJane walking over to your left side then you are still tracking one Jane.

And if Jane's face looks like a shoe when she stands on your left, but she melts your heart when she moves to your right - you should probably check your eyes...

The L of I refers to a reality, not the placeholder for the reality.

You have no direct access to reality except through your mind/experiences.
All you have is placeholders.

Symbols.

[Speakpigeon]

[Well I think the law of identity is more like a convention. The English word "law" doesn't always refer to things inherent to the universe. (Just think of Murphy's law hehe or Moore's law.)

Sure, but I still don't see anything to think of in support of your suggestion that the Law of Identity is a convention.

I think the law of identity is accepted and used by rather every sane person, without this we are insane and nothing ever makes any sense anymore, so one could also say that it's like a quasi-universal convention or a quasi-law.

In other words, it's a law in all but name. Oh, wait, in name, too!

But thinking is always subjective, varies from person to person, and varies throughout each person's lifetime. Laws of thought are not inherent to the universe, even if as far as we know every thing is objectively itself.

???
Did I just see you speak of subjective/objective?!
I thought these were Cartesian ideological constructs devoid of reality?
Are you being yourself here?

Still, sure, thinking is highly subjective but you just admitted that "every sane person" would in fact think in the same way by abiding to this quasi-law of Identity that apply to very nearly all of us save for the insane and presumably the already-dead and those missing their brain.

The existence of reality is inherent to everything, there is even less to assert there I think. I would call this an objective, universal law. (Which does break down at some point I think, in a certain sense, but that's very off-topic.)

So, now it's an "objective" law?! You're spreading yourself all over the place here, like quantum particles.
OK, so, since this "breaking down" is off topic, I take it this quasi-law in fact doesn't break down in any relevant sense and therefore it's a law, and even an objective law, one that very subjective people all have to abide by.
EB

[Speakpigeon]

The Law of Identity is an instance of tautology.

The Modus ponens is a tautology but we assume it as an axiom because we can' t prove it without using the Modus Ponens.
Still, we assume it in formal logic because we can then use it as a rule of inference to produce convincing proofs, which is both very convenient and very realistic since Modus Ponens is the workhorse of our logical intuition.
And there are millions of examples of the formal use of the Modus Ponens starting with the Stoics 2,300 years ago.
But I don't remember the Law of Identity being used in a formal proof. I wonder why that is.

A thing is identical to itself. Examined at different times, it is still identical to itself. Examined in different locations, it is still identical to itself.

Examined? So now the Law is not that a thing is itself, but that it looks like itself?

I mean the whole, per se, without consideration of its contents and the contents, per se, without consideration of the whole.
Let's say that you have a glass beaker containing a blue liquid. You are going to examine the beaker and the liquid before and after pouring 1/2 of the liquid out. The beaker is the same before and after the liquid is poured. The beaker is identical to itself before and after. The liquid is not the same before and after its pouring. It lacks the property of equality. Had you not poured any of the liquid out, it would have been equal to itself.

But you said "Identity is sameness of the whole. Equality is sameness of the contents".
So, according to you, reality can be described in terms of a collection of different containers, all unique, so that each container is itself, but with various contents, with one content of a container possibly equal to that of a different container...
And, crucially, the contents of any container can change so that the container remains itself even though... What? Even though it has now different contents?
EB

[Speakpigeon]

SP,
You wanted the common, intuitive definition, yeah?
As I say...
The L Of I is: The thing is the thing and no other. My coffee cup is my coffee cup and no other. I am me and no other.
Seems to me I satisfied your requirements of "don't ramble. Keep to the point and leave the question of the logic of it to the other forum."
Seems to me a few other folks have satisfied your requirements too.

Sure, but somebody (else?) went a bit further to explain the Law...

Only if comparing two different Janes.
But "LeftJane is LeftJane' is true.
The L of I refers to a reality, not the placeholder for the reality.
You can have 1000 Janes, which is to say 1000 unique individuals all sharing the same placeholder.
The placeholder, the label, the signifier, is not identity. Identity resides with the reality the placeholder is attached to.
The placeholder just holds the place, it's a device for recognition and categorizing, not the foundation of 'identity'.

So, you mean, the Law just means that a thing really is itself and that's a law.
But, what's the use of saying that?
EB

[Speakpigeon]

The L of I refers to a reality, not the placeholder for the reality.

Could you give examples of instances of you actually knowing the reality of some things?
EB

[Scott Mayers]

I'm not interested in the role that the Law of Identity has in logic. So, the Wiki article is somewhat irrelevant. I'm interested in the law itself and what it means for us.

Oh. I've wasted my time here then. That was the ONLY meaning of the "law of identity" that I was aware of .

Yet, I have been clear from the start...

This thread is motivated by a dispute about the Law of Identity in the Logic & Philosophy of mathematics forum. However, this thread is about the Law of Identity. It isn't a thread about logic itself. So, please, remember we don't care about logic per se here.
and leave the question of the logic of it to the other forum.

Maybe the treatment of the Law of identity in logic is relevant to our intuitive notion of the Law but you would have to explain why it is.
EB

The "Law of Identity" is ONLY about logic. You CAN define it outside of logic but then this is just free to be defined by people in an infinite ways.

Example, let "Law of Identity" be defined as "the legislated public law in the city, X, that says you must have three formal documents that indicate your place of residence, one for your age (birth certificate), and at least one piece of photo identification approved by the city X."

You need to define what you mean and why you ask with clarity up front. Otherwise, you could have asked, "what does the Law of Berchelistomitoba mean to you?" What context have you heard the noun-phrase, "Law of Identity", to which you are asking outside the context of logic?

[henry quirk]

"So, you mean, the Law just means that a thing really is itself and that's a law."

It means the thing is the thing and is no other thing. And it's a 'law' in the way 'law' is used in 'the laws of physics' which is to say it's a codified observation on what 'is'.

#

"But, what's the use of saying that?"

Hell if I know.

#

"Could you give examples of instances of you actually knowing the reality of some things?"

Already did a damn fine job of that over in your moon thread.

##

"Symbols"

See that there is where the gap is: you think it's symbols, symbols, and nuthin' but symbols; me, as a direct realist, I make a clear and clean distinction between placeholder (Jane) and that which has its place held (a particuiar woman who calls herself Jane).

Absolutely, if Reality is just symbols (all the way down) then the L of I is meaningless, but if Reality is 'real' then it's perfectly sensible for me to talk about the two or more 'Janes' cuz 'Jane' is just a placeholder that can be applied to a whole whack of unique entities, each one it(her)self and no other.

#

"The law of identity is about figuring out how many variables you are tracking"

That ain't how I see it.

Again: 'the thing is the thing and is no other thing' is the sum of the 'law'. We name shit, categorize shit, but 'identity' is intrinsic to the shit (a particular woman who calls herself Jane is 'that' woman and is no other woman who calls herself Jane).

[commonsense]

The Law of Identity is an instance of tautology.

The Modus ponens is a tautology but we assume it as an axiom because we can' t prove it without using the Modus Ponens.
Still, we assume it in formal logic because we can then use it as a rule of inference to produce convincing proofs, which is both very convenient and very realistic since Modus Ponens is the workhorse of our logical intuition.
And there are millions of examples of the formal use of the Modus Ponens starting with the Stoics 2,300 years ago.
But I don't remember the Law of Identity being used in a formal proof. I wonder why that is.

A thing is identical to itself. Examined at different times, it is still identical to itself. Examined in different locations, it is still identical to itself.

Examined? So now the Law is not that a thing is itself, but that it looks like itself?

I mean the whole, per se, without consideration of its contents and the contents, per se, without consideration of the whole.
Let's say that you have a glass beaker containing a blue liquid. You are going to examine the beaker and the liquid before and after pouring 1/2 of the liquid out. The beaker is the same before and after the liquid is poured. The beaker is identical to itself before and after. The liquid is not the same before and after its pouring. It lacks the property of equality. Had you not poured any of the liquid out, it would have been equal to itself.

But you said "Identity is sameness of the whole. Equality is sameness of the contents".
So, according to you, reality can be described in terms of a collection of different containers, all unique, so that each container is itself, but with various contents, with one content of a container possibly equal to that of a different container...
And, crucially, the contents of any container can change so that the container remains itself even though... What? Even though it has now different contents?
EB

Mea culpa

[Speakpigeon]

The "Law of Identity" is ONLY about logic.

Well, it's a law of thought and as such it certainly has juridiction over logic. But saying only logic is concerned is like saying the laws of nature are only about science. So, you do it if you want to but for me, no thanks.

Example, let "Law of Identity" be defined as "the legislated public law in the city, X, that says you must have three formal documents that indicate your place of residence, one for your age (birth certificate), and at least one piece of photo identification approved by the city X."

Sure, that's a very convincing piece of rhetoric but nothing like a rational argument.

You need to define what you mean and why you ask with clarity up front.

That's exactly what I did. I'm asking about the Law of Identity and I'm not interested in the logic of it. I think it's very clear. And it's OK if you can't answer that.

What context have you heard the noun-phrase, "Law of Identity", to which you are asking outside the context of logic?

Mathematical logic.
EB

[Speakpigeon]

"So, you mean, the Law just means that a thing really is itself and that's a law."

It means the thing is the thing and is no other thing. And it's a 'law' in the way 'law' is used in 'the laws of physics' which is to say it's a codified observation on what 'is'.

#

"But, what's the use of saying that?"

Hell if I know.

You realise that philosophers, logicians, mathematicians have been reasserting this law for more than 2,400 years! Asserting it seems crucial...
EB

[Speakpigeon]

Mea culpa

Nothing to be culpa about.
ZB

[Logik]

You realise that philosophers, logicians, mathematicians have been reasserting this law for more than 2,400 years! Asserting it seems crucial...
EB

No, they haven't They have been ASSUMING it, not ASSERTING it.

An assertion is the output of a reasoning process. An assumption is axiomatic.

If it were an assertion then you ought to assert it yourself from first principles via a testable/reproducible/falsifiable methodology. Show us.

[henry quirk]

"Asserting it seems crucial..."

Can't see why: it is what it is, plain as the nose on a face. Only retards (or philosophers) pick at these nits.

[Atla]

[Well I think the law of identity is more like a convention. The English word "law" doesn't always refer to things inherent to the universe. (Just think of Murphy's law hehe or Moore's law.)

Sure, but I still don't see anything to think of in support of your suggestion that the Law of Identity is a convention.

I think the law of identity is accepted and used by rather every sane person, without this we are insane and nothing ever makes any sense anymore, so one could also say that it's like a quasi-universal convention or a quasi-law.

In other words, it's a law in all but name. Oh, wait, in name, too!

But thinking is always subjective, varies from person to person, and varies throughout each person's lifetime. Laws of thought are not inherent to the universe, even if as far as we know every thing is objectively itself.

???
Did I just see you speak of subjective/objective?!
I thought these were Cartesian ideological constructs devoid of reality?
Are you being yourself here?

Still, sure, thinking is highly subjective but you just admitted that "every sane person" would in fact think in the same way by abiding to this quasi-law of Identity that apply to very nearly all of us save for the insane and presumably the already-dead and those missing their brain.

The existence of reality is inherent to everything, there is even less to assert there I think. I would call this an objective, universal law. (Which does break down at some point I think, in a certain sense, but that's very off-topic.)

So, now it's an "objective" law?! You're spreading yourself all over the place here, like quantum particles.
OK, so, since this "breaking down" is off topic, I take it this quasi-law in fact doesn't break down in any relevant sense and therefore it's a law, and even an objective law, one that very subjective people all have to abide by.
EB

Whatever, just like in you other threads, if you have a point or a strong belief, you either refuse to tell what it is, and/or you can't communicate in English.

[Scott Mayers]

The "Law of Identity" is ONLY about logic.

Well, it's a law of thought and as such it certainly has juridiction over logic. But saying only logic is concerned is like saying the laws of nature are only about science. So, you do it if you want to but for me, no thanks.

and

What context have you heard the noun-phrase, "Law of Identity", to which you are asking outside the context of logic?

Mathematical logic.
EB

First off, the "laws of thought" are called such because our mind is what acts as the justifying factor that defines logic by past philosophers of logic. Many who disagree with calling these laws about thought still have to agree that they are about the minimal agreements of rules of conduct prior to particular system or class of systems between two or more minds. I gave my examples above in light of this purpose, whether other authors actually stated it or not.

Secondly, prior to the early 1800s, many called logic, "mathematical", because only in math prior to George Boole and Leibniz, had such concise exactness belonged more to math versus non-mathematical philosophical dialectic. I have books from that period that should you extract what they teach out, you can match it with modern texts on logic without the term. Before that period, Aristotle's use of the syllogism and informal fallacies, (like "Equivocation") were often used as rhetoric, the study of how to get what you want using various tactics in speaking or writing, one only of which was logic. Also, syllogisms didn't cover the full range nor was discussed on a metalogical depth whereby logicians begun to desire proving the validity and/or soundness of any logical systems, whether of thought or in physical reality, nature apart from our human utility of rationalizing things.

As science rose in power, many opted to divorce it from the rest of logical analysis alone. Many also place our own senses as above that of analyzing apriori assumptions used in validating arguments. Regardless, the "laws of thought" were what those like George Boole opted to call the processes due to mind distinct from mere sense data that we use as input to logical arguments. Logic was/is about validation of arguments that IGNORE the particular truth values of the premises going into them.

Example, let "Law of Identity" be defined as "the legislated public law in the city, X, that says you must have three formal documents that indicate your place of residence, one for your age (birth certificate), and at least one piece of photo identification approved by the city X."

Sure, that's a very convincing piece of rhetoric but nothing like a rational argument.

You need to define what you mean and why you ask with clarity up front.

That's exactly what I did. I'm asking about the Law of Identity and I'm not interested in the logic of it. I think it's very clear. And it's OK if you can't answer that.

You are presuming the 'laws of thought' were laid down by non-logicians. The common meaning of the laws were meant to discuss LOGIC specifically from an 'outsiders' eye looking in on what is common to all forms of logical systems, including scientific reasoning.

And if you are "asking about the Law of Identity", you require understanding the motives for the creation of the set of "laws of thought". If you are NOT interested in the 'logic' of it, what are you bothering to speak about this for? ....artistic interpretation? ...literature? Why EXCLUDE the very subject, LOGIC, as the meas to discuss this?