Monday, August 14, 2017

August 14, 2017 Monday

Bedtime Story 


Taking Care of the Vicious Circle of Logic


Last night we saw how according to Tarski a truth statement is best stated.

“Coal is black” is true if and only if coal is black.

We had labeled it as statement [A].

Many may argue that in [A] there exists a basic flaw that goes by the name of vicious circle in logic.

They point out that the word “coal” is occurring both in the definiens and the definiendum.

But that can be explained.

The word “coal” albeit the same on the two sides has different usage in those two places.

On the right side in the definiendum “coal” is syntactical where it the subject of a sentence - coal is black.

Now on the left hand side, the definiendum it is part of a whole phrase within quotation marks “coal is black”.

The whole phrase “coal is black” is being treated as one block about which something is being said.  

If you recall, this point had come up when we were discussing Gödel’s theorems.

It was one of those bedtime stories when I tried to explain the difference between mathematics and meta-mathematics.

While mathematics actually deals with signs and numbers, the meta-mathematical statements even if they contain the numbers, signs and formulas treat them simply as names and not anything more.

So we can write 5 + 5 = 10 as a statement of arithmetic.

But when we say “5 + 5 = 10” is a true mathematical statement, the equation is being kept in quotes and is being treated as a single entity wherein each number or sign is mathematically irrelevant.    

Similarly in our present case scenarios, the very fact that the phrase is enclosed within quotes calls for taking it as grammatically a single entity.

This makes the use of the word “coal” on the left hand side just a part of the whole object “coal is black” about which something is being said.

Hence the coal on the left hand side is not a syntactical part of the whole phrase.

The words that are not a syntactical part of the definiendum cannot create the vicious cycle that was being referred to and thus that fallacy is taken care of.

Tarski says that there is yet another way in which this vicious cycle can be taken care of.

Have a look at the formulation [A] once again.

[A] “Coal is black” is true if and only if coal is black.

Here the method deployed in naming the sentence or the expression was to put it inside quotation marks.

Stay tuned to the voice of an average story storytelling chimpanzee or login at http://panarrans.blogspot.com
                              
Good night mon ami and my fellow cousin ape.
                           
  
                

             












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Another great educator and a teacher that I am aware of is Professor Subhashish Chattopadhyay in Bangalore, India.

While I narrate stories, Professor Subhashish an electronic engineer and a former professor at BARC, does and teaches real mathematics and physics.

He started the participation of Indian students at the International Physics Olympiad.

Do visit him here:


All his books can be downloaded for free through this link:


For edutainment and English education of your children, I recommend this large collection of Halloween Songs for Kids:


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