Introduction to Logic

1. LOGIC - Defined as the science and art which
helps our mind to ditinguish between the
correct from the incorrect.

2. PURPOSE OF LOGIC
• TO ATTAIN CLARITY IN OUR THOUGHTS AND VALIDITY
IN OUR PROCESSES OF INFERENCE.
• DISTINGUISH BETWEEN GOOD AND BAD REASONING
AND BETWEEN CORRECT AND INCORRECT
ARGUMENTS.
• TO ATTAIN TRUTH AND VALIDITY IN REASONING.

3. THREE DISTINCT ACTIVITIES OF LOGICIANS:
1. ANALYSIS
THE DETERMINATION BETWEEN AN ARGUMENT AND NON-
ARGUMENT.
2. CLASSIFICATION
IT INCLUDES THE DISTINCTION BETWEEN INDUCTIVE AND
DEDUCTIVE ARGUMENTS.
3. ASSESSMENT
TO DETERMINE THE CORRECTNESS AND INCORRECTNESS OF
CERTAIN ARGUMENTS.

4. PROBLEM- SOLVING
 ONE IMPORTANCE OF LOGIC IN OUR DAILY LIFE IS THAT IT
HELPS US SOLVE PROBLEMS THAT MAY OCCUR IN OUR DAY
TO DAY LIVING. INASMUCH AS LOGIC HELPS US DEVELOP
CRITICAL THINKING. IT, THEREFORE, HELPS US IN
ANALYZING PROBLEMS THAT MAY ARISE FROM A CONFLICT
DUE TO THE COLLISION BETWEEN SITUATIONS AND OUR
BELIEFS.

5. PROBLEM- SOLVING
 IN TRYING TO SOLVE PROBLEM, IT IS IMPERATIVE TO
APPLY REASON IN A PROBLEMATIC SITUATION IN
ORDER TO UNDERSTAND THE PROBLEM AND
IDENTIFY THE PROPER METHOD TO BE USED IN
ORDER TO OBTAIN THE SOLUTION TO THE PROBLEM.

6. • REASON CAN ONLY BE APPLIED WHEN THERE IS A
SITUATION THAT HAS TO BE THOUGHT ABOUT.
– ACCORDING TO JOHN DEWEY
“MEN DO NOT, IN THEIR NATURAL STATE, THINK WHEN
THEY HAVE NOT TROUBLE TO COPE WITH,NO DIFFICULTIES
TO OVERCOME. A LIFE OF EASE, OF SUCCESS WITHOUT
EFFORT, WOULD BE THOUGHTLESS LIFE, AND SO WOULD A
LIFE OF READY OMNIPOTENCE.”

7. LET US TRY TO SOLVE THIS PROBLEM:
• THE HIGHEST POSITION IN THE LARGE COMPANY, THE
PRESIDENT, THE VICE PRESIDENT, AND THE CHAIRMAN OF THE
BOARD OF TRUSTEES, ARE HELD BY MR. LACSAMANA, MR
MALABANAN, AND MR. NUNEZ, THOUGHT NOT NECESSARILY IN
THAT ORDER. HOWEVER, WE DO NOT KNOW WHO HOLDS EACH
POSITION EXCEPT THAT WE WERE ONLY GIVEN TWO DATA THAT
WILL HELP US IDENTIFY THE POSITION BEING HELD BY THE
THREE PERSON:

8. LET US TRY TO SOLVE THIS PROBLEM:
 THE VICE PRESIDENT, WHO IS A BACHELOR, EARNS THE LEAST.
 MR. NUNEZ, WHOM MARIED THE SISTER OF MR. LACSAMANA'S
WIFE, EARNS MORE THAT THE PRESIDENT.
“WHAT POSITIONS DOES EACH OF THE THREE PERSONS
HOLD?”

9. • IN DEALING WITH THIS LOGIC PUZZLE, IT IS NECESSAY THAT WE CONSTRUCT A
TABLE WHICH WE WILL FILL IN AS WE ACCUMULATE INFORMATION BASED FROM
OUT ANALYSIS. FOR INSTANCE,
• OF MR. LACSAMANA'S WIFE
CHAIRMAN PRESIDENT VICE PRESIDENT
MR. LACSAMANA
MR. MALABANAN
MR. NUNEZ
IN ANALYZING THE GIVEN DATA IN THE PROBLEM, WE ARE GIVEN THE FACT THAT MR. NUNEZ MARRIED
THE SISTER OF MR LACSAMANA'S WIFE. FROM THIS, WE CAN SAY THAT BOTH MR. NUNEZ AND MR. LACSAMANA
ARE MARRIED. THEREFORE, THIS SUGGEST THAT THEY CANNOT BE THE VICE PRESIDENT BECAUSE AS
MENTIONED, THE VICE PRESIDENT IS A BACHELOR. AS SO, GOING BACK TO THE TABLE, WE HAVE TO PUT AN “N”
MARK (NOT APPLICABLE) TO MARK THAT MR. LACSAMANA AND MR NUNEZ CANNOT BE THE VICE PRESIDENT.
HENCE,
CHAIRMAN PRESIDENT VICE PRESIDENT
MR. LACSAMANA N
MR. MALABANAN
MR. NUNEZ N

10. – IN THE ANALYSIS OF THE TABLE PRESENTED, THERE'S NO
DOUBT ANYMORE THAT MR. MALABANAN IS THE VICE PRSIDENT
OF THE CORPORATION. THEREFORE, WE HAVE TO PUT AN “A”
MARK (APPLICABLE) TO INDICATE THAT MR. MALABANAN IS THE
VICE PRESIDENT; AND PUT AN “N” MARK TO POSSIBILITY OF MR.
MALABANAN AS BEING THE PRESIDENT OF THE
CHAIRMAN.THEREFORE, THE ENTRIES THAT WE HAVE MADE SO
FAR WILL BE THIS:
CHAIRMAN PRESIDENT VICE PRESIDENT
MR. LACSAMANA N
MR. MALABANAN N N A
MR. NUNEZ N

11. – GOING BACK TO THE DATA GIVEN, IT WAS MENTIONED THAT MR. NUNEZ
EARNS MORE THAN THE PRESIDENT . WE CAN, THEREFORE, CONCLUDE FORM
THIS THAT MR. NUNEZ CANNOT BE THE PRESIDENT. IN THIS REGARD, THE ONLY
POSSIBLE THING IS THAT MR. NUNEZ IS THE CHAIRMAN OF THE BOARD OF
TRUSTEES. AS THE CHAIRMAN IS NORMALLY EARNING MORE THAN THE
PRESIDENT. THUS, THE TABLE WILL APPEAR AS.
CHAIRMAN PRESIDENT VICE PRESIDENT
MR. LACSAMANA N A N
MR. MALABANAN N N A
MR. NUNEZ A N N

12. – REASONING PROBLEM OF THIS KIND ARE INDEEED OF GREAT
INTEREST AND PROVIDE GREATER EXCITEMENT BECAUSE THEY
MIRROR SOME WAYS THE LOGICAL CHALLENGE OFTEN PRESENTED
BY SITUATION IN REAL LIFE. IN THIS CASE, THE STUDY OF LOGIC IS
ALL THE MORE JUSTIFIED BECAUSE IT IS DEEM TO BE VERY MUCH
USEFUL IN SOLVING THE REAL PROBLEMS IN LIFE.