Speakpigeon wrote: ↑Mon Mar 04, 2019 6:36 pm
Scott Mayers wrote: ↑Mon Mar 04, 2019 3:34 pm
"
The law of Identity" is a
logical apriori assumption or agreement to what one means minimally about what is considered logical. For any given concept, symbol, or referent, if given some concept referenced by a label, say X, it is related to the concept referred by it uniformly by the label, X, wherever it is used.
You think people don't usually comply with the Law of Identity in everyday speech?
That is why I used the example below of a joke. Humor is a significant factor of humanity. It is based one's clever capacity to "trick" ourselves by breaking the rules of consistency. It if a function of all the arts. If we were perfectly logical, we'd not be able to be tricked. Although I disagree with the over-stereotyped science fiction concern against the robots or cyborgs, etc, there is truth to the nature of normal solid-state electronic computers to be able to replicate the full range of emotional content because emotions (including all sensations to some degree) rely on a relatively INDETERMINATE environment. The logic of biochemistry for animals requires adapting to the indeterminate variable experiences though variable environments.
Speakpigeon wrote:
Scott Mayers wrote: ↑Mon Mar 04, 2019 3:34 pm
As to the expressions of the form,
xRy
The
R represents the relationship of the symbol
x on the left, to the symbol
y on the right. If we want to define some
R as something such that some meaning of
x is assigned to
y, such that the meaning of
y identifies with
x as being uniquely referring to the same meaning by either force or comparison, then we call that
R an Identity relationship of
y to
x.
A definition that uses a symbol on one side, usually the left, IDENTIFIES the meaning of something more explanatory on the other.
"Cat" is "an animal" [meaning, a cat is identified (at least) as an animal]; but
"animal" is-not "a cat"
How exactly does writing "A cat is an animal"
assigns meaning to the term "cat"?
The form of the genus/specie definition, important in the logical defining of terms, would treat the class, "animals", as the parent or genus class to which a cat belongs to. The expression, "A cat is an animal." is at least
true as it
assigns the meaning of cat to be at least IDENTIFIED as some animal.
In computers, most higher-ordered languages simply use the "=" as this type of operator:
x = 2
...but reverses the order. "2" is assigned to the class variable, "x", where "x" doesn't
require being only "2". Another way to express this to see the relationship, is
Let x represent some Number.
Then if x = 2, 2 is the particular Number in x.
Speakpigeon wrote:
Scott Mayers wrote: ↑Mon Mar 04, 2019 3:34 pm
It is an agreement of those opting to play a game to follow the exact same rules with the same meanings shared rather than to arbitrarily confuse or change the meaning of the words or symbols used arbitrarily.
I would say that "Law of Identity" is a very strange name to use to do what you suggest here. I would call it a rule, not a law, just like you don't have the law(s) of football or the law(s) of chess but
rules.
So, unless you can justify your perspective, I don't think I'll buy it.
The word "identity" is being treated broadly by you and logik here. This is 'tricking' YOU because you assume the meaning of it in one context should be universal when there are more than one meaning. The error you guys are making is to interpret the "Law of Identity" to be imposed by Aristotle's use of the verb "are" or "is" as this law when that particular law is only the 'equality' type relationship, NOT the 'assignment' type.
Speakpigeon wrote:
Scott Mayers wrote: ↑Mon Mar 04, 2019 3:34 pm
Why require [a law of identity] when it seems it already applies?
Exactly. This is the crucial point here and you dismiss it much too quickly.
Because it defines what is minimally accepted in formal logic using language that expresses things linearly.
x = x
means the symbol, x, variably standing for any proposition, term, constant, or variable, remains constant in meaning through an argument. That is, you cannot use different meanings of homonyms or synonyms, variants of different parts of language uses (like noun or verb). You have to
agree to keep what you use "consistent" and why this law is important. You both BREAK this law when YOU expect that law to be REQUIRED to fulfill the different meanings of "identities" used in specific instances of logic, like that the symbol for equality I demonstrated as "=" for this law, would require being interpreted as "==" in computers so as not to confuse it to mean an assignment operator in higher order languages.
Speakpigeon wrote:
Scott Mayers wrote: ↑Mon Mar 04, 2019 3:34 pm
It doesn't apply if people do not DEFINE their TERMS in a philosophical debate and is often the reason FOR disagreement.
According to this, if anyone uses the word "true" first to mean true and then to mean false within the same argument, then the law of identify is falsified?!
Please clarify.
The words we use to symbolize something we define is ARBITRARY. So you
can technically define the symbol, "true", to be assigned to the constant, 0, in computers. If this is used, then the word's human meaning doesn't fit with the particular computer's normal use of the Boolean, "true", that is actually assigned as "true" = 1.
Speakpigeon wrote:
Scott Mayers wrote: ↑Mon Mar 04, 2019 3:34 pm
"to find one's head and shoulders on a beach" =?= "to find one's Head & Shoulders™ on a beach."
I believe the Law of Identity means something a bit deeper than
a redundant injunction not to equivocate.
If that was what it meant, we would call it "
Rule against equivocation" or some such. And we do have it in logic. It's called the "
fallacy of equivocation".
EB
That is precisely what it means. The word "law" is used for the static meaning. It is a "rule" in that this means the PRACTICE of logic, as though is were a game's rule we agree to when we play the game called, "logic".
What became questioned in the field of logic was to how the rest of the laws were to apply when you can have more than just binary truth values. Reality does permit the contradiction, "x & not-x", because you can have say, three values = {0, 1, 2} to some system.
If given
x = 0, both "1 = not-x " and "2 = not-x" in this case. If I then ask you if "x = not-2", you'd assert this true. But "1 = not-2" also. So I might replace the not-2 in "x = not-2" with "1" and have "x = 1", If I now replace the "1" in that to "not-x", we have,
x = not-x.
This is still 'consistent' but is a logic of three values and why the question about consistency arose in the first place. But the problem is about a confusion in the meanings of "=" that differ. The three apriori laws are about the 'truth' value of the logic systems themselves. In other words they assume
a prior postulate to all logic systems with those three laws. The problems raised for others is that this 'game' of logic doesn't permit the multivalued versions yet we can see they still have RATIONALITY. Thus, such a system based only on these restrictions of consistency, cannot define all rational systems without treating the meaning of logic restricted to those laws. The contention is that some think we require KEEPING those laws and then say that "logic" being defined as requiring those laws by most, must treat the other forms of reasoning as "non-logical" OR extend the meaning of "logic" to have other initial rules. Consistency is always one that is kept but the other two, "The law of the Excluded Middle" or the "Law of non-contradiction" can be changed to form new kinds of 'logic.'