Logic, a definition

[niin]

Logic, a definition

To define is to understand...

My look on logic and how we use it.

The humand mind use a system with gives "value" to information.
When we talk about this value, it is allways in relation to what we are talking about.
When talking logic one can use this "value" to grade statements.

"High" value statements is called "logical" statements.
"Low" value statements is called "illogical" statements.
"Max" value statements is called "true" statements.
"Minimum" value statements is called "false" statements.

High or low value is somthing that varies from person to person.
As such it can be difficult (if not impossible) to come to agreement with another person as to what is logical.
"Arguing" logic is only reasonable using max (or minimum) value statements.
You can use high value statement to work out other "logical" statements, but you can not say that logic tell...that this information is true.
To do that we have to agree to a reference frame for which to dicuss the statement. This "frame of reference" must be a max (or minimum) value statement.

This is the basic definition as i see it.

Anyone who want to discuss this?

[ronthepon]

I would suggest an alternate definition:
A process by which a group of statements are used to gauge the truth value of a compound statement.

I get the feeling that I know nothing in this feild by the looks on your faces.

[niin]

Originally Posted by ronthepon

I would suggest an alternate definition:
A process by which a group of statements are used to gauge the truth value of a compound statement.

This would be more in the way of defining logical argumentation.
My post is supposed to be a definition of the concept of logic.
I am not saying your definition is wrong...only that you are defining something ells.

[ronthepon]

So what you are interested in is a definition for the logic we refer to when we gauge IQ?

Well, that's better, because I hate mathematical logic.

I'll be checking this thread out frequently then...

[niin]

Originally Posted by ronthepon

So what you are interested in is a definition for the logic we refer to when we gauge IQ?

Well, that's better, because I hate mathematical logic.

I think a IQ test is a pattern recognition and calculating test.
Logic do not seem nessesary for taking one.

The definition of the concept of logic is surpossed to include mathematical logic.

[Racoon]

Originally Posted by niin

The definition of the concept of logic is surpossed to include mathematical logic.

This is an interesting thread Niin.

People talk about being logical all the time. And we know that many people act "illogically".

I think you made a good point on values. But you need to define those values a little more clearly.
What if I said something like "Trees are Big" ?

Mathematic logic is simpler. If A + B = C, then C = B + A.

as for Logical arguement, it needs a structure.
premise &
conclusion

and the two types of logical arguement
deductive
Inductive

For logic to be valid, all the premises are true, and hence its conclusion is true.

Trees are Big. Yes, trees are big. But , not all trees are big.
= Not good logic. Lower "value" in your definition...

I have a little more, but I'll see what everyone thinks about this so far.

Does it sound Logical??
Racoon

[Tormod]

Originally Posted by niin

To define is to understand...

I beg to differ. A definition in this sense is not understanding but an attempt to quantify something. If I say "vacuum is the absence of matter" then what sort of understanding have I provided? It is all relative - it will depend on how much the reader knows (ie, it has a knowledge bias).

You can use high value statement to work out other "logical" statements, but you can not say that logic tell...that this information is true.
To do that we have to agree to a reference frame for which to dicuss the statement. This "frame of reference" must be a max (or minimum) value statement.

I don't understand what you're saying. Are you saying that if we agree upon the limits of logic, we will know what is true and what is false? Or are you saying that we can reach a concensus?

Now, why would a consensus be interesting?

Science is about finding the theories that best explain what we observe, and then test them. This requires logic, but it also requires certain leaps of faith (we must assume that such and such is true). But the very fundamental concept of the scientific method disallows us from ever proving anything *final*, thus we can never really know any "truth", regardless of how well we define the limits of anything (and how do we quantify these limits in the first place?).

[hallenrm]

Originally Posted by Tormod

Now, why would a consensus be interesting?

Science is about finding the theories that best explain what we observe, and then test them. This requires logic, but it also requires certain leaps of faith (we must assume that such and such is true). But the very fundamental concept of the scientific method disallows us from ever proving anything *final*, thus we can never really know any "truth", regardless of how well we define the limits of anything (and how do we quantify these limits in the first place?).

A very useful input indeed Tormod! So lets proceed further.

I tried the wikipedia for a definition of logic (encyclopedias are often a good source of definitions!)

Here's its intro

Logic, from Classical Greek λόγος (logos), originally meaning the word, or what is spoken, (but coming to mean thought or reason) is most often said to be the study of criteria for the evaluation of arguments, although the exact definition of logic is a matter of controversy among philosophers. However the subject is grounded, the task of the logician is the same: to advance an account of valid and fallacious inference to allow one to distinguish good from bad arguments.

Traditionally, logic is studied as a branch of philosophy. Since the mid-nineteenth century logic has been commonly studied in mathematics, and, even more recently, in computer science. As a formal science, logic investigates and classifies the structure of statements and arguments, both through the study of formal systems of inference and through the study of arguments in natural language. The scope of logic can therefore be very large, ranging from core topics such as the study of fallacies and paradoxes, to specialist analyses of reasoning such as probably correct reasoning and arguments involving causality

Evidently, logic is not the most useful tool for real science. Generally it is used for creating a false impression, that is for obfusication.

[niin]

Originally Posted by Racoon

I think you made a good point on values. But you need to define those values a little more clearly.
What if I said something like "Trees are Big" ?

I usually think of the "value" as "usefullnes". Like infomation, that can be used to predict the future, is pretty usefull.

"Trees are Big" would be a logical stamenet to you, if you had only ever seen big trees.
If I had seen "small" trees then i would say...that it is a false statement.
I could never convince you bye arguing, unless you agree to a premise(s) that can be used to logical show it to be false.

Like this:
premise 1: "A tree can be big"
premise 2: "A tree can be smal"
we could then compare the statments and conclude that the statment "Trees are Big" is false

Originally Posted by Racoon

as for Logical arguement, it needs a structure.
premise &
conclusion

This is included in my definition.
You argree to a "max (or minimum) value statement" (premise) and you use comparativ logic to get "logical statement" (conclusion)

Originally Posted by Tormod

If I say "vacuum is the absence of matter" then what sort of understanding have I provided?

A definition is a true statement
If I agree that your statement is a definition. then i get the understanding that is your statement. The knowledge.
The closer a definition is to being true the better the understanding is.

Originally Posted by Tormod

I don't understand what you're saying. Are you saying that if we agree upon the limits of logic, we will know what is true and what is false?
Or are you saying that we can reach a concensus?

If i understand you correctly...concensus
"consensus" is the same as "agreement"

Originally Posted by Racoon

Now, why would a consensus be interesting?

Usually people doesn't do stuff unless it agrees with em.

[Racoon]

You mis-quoted me Niin, at the bottom of your last statement.
I understand English is not your first language, so lets be considerate

When I say "Trees are Big" does that imply I mean all trees?
Don't I know that trees start out small but grow big?

therefore Trees aren't always big, but I perceive trees to be big.



In a deductive logic argument, the Truth or Falsehood of its conclusion does not determine the validity or invalidity of an argument, Nor does the validity of an argument gaurantee the truth of its conclusion.

Ok, I confused myself

You make categorical propositions - which offer assertions about classes - affirming or denying that one class is included in the other.

you then need to consider:
Posteriori -
* an arguement from effect to cause
* Knowledge based on experience

Priori -
* Argument from cause to effect
* Knowledge independant of experience

there is also
the universal - what is common to many different items (eg. redness is common to all things red (Trees need CO2)

The particular - Single, or individual, as distinct from class or universal.
"sometimes" (sometimes Trees are Big)

Does any of this make sense to you Niin?
because I am confused!