Presented by:Umer Usman

Presented to:Miss Iram Saba

LOGIC AND

HISTORY OF LOGIC

The term "logic" came from the Greek word logos, which is sometimes translated as "sentence", "discourse", "reason", "rule", and "ratio".

Logic was studied in several ancient civilizations, including India, China, Persia and Greece.

In the West, logic was established as a formal discipline by Aristotle, who gave it a fundamental place in philosophy.

In the East, logic was developed by Buddhists.

DEFINITION OF LOGIC

Logic is the systematic process of valid reasoning through inference — deriving

conclusions from information that is known to be true. It is the area of

philosophy that is concerned with the laws of valid reasoning.

TYPES OF LOGIC

Formal Logic: It is mainly concerned with formal systems of logic. These are

specially constructed systems for carrying out proofs, where the languages and

rules of reasoning are precisely and carefully defined.Reason for studying Formal Logic: Its helps us to identify patterns of good reasoning and patterns

of bad reasoning, so we know which to follow and which to avoid.

help improve critical thinking. Its also used by linguists to study natural languages. Computer scientists also employ formal systems of logic in

research relating to Artificial Intelligence.

TYPES OF LOGIC

Informal Logic: The term "informal logic" is often used to mean the same thing

as critical thinking. Sometimes it is used to refer to the study of reasoning and

fallacies in the context of everyday life.

Symbolic Logic: Symbolic logic is the method of representing logical

expressions through the use of symbols and variables, rather than in ordinary

language.

IMPORTANCE OF LOGIC

A study of logic can help a person better construct their own arguments and

Critique the arguments of others. It isn't uncommon for many popular

arguments to be filled with errors and fallacies because so many people are

simply unaware of how arguments are correctly formulated.

The two main methods of reasoning are called deduction and induction.

Deduction: It works from the general to the more specific. In deduction, the conclusion is logically follows from the premises; it is a necessary conclusion and is true.

Examples of Deductive Logic: All squares are rectangles. All rectangles have four sides. Logic,

therefore, tells you that all squares have four sides.

It is dangerous to drive when it is snowing. It is snowing now. Logic tells you that it would be dangerous to drive right now.

When it rains the trees get wet. The trees are wet this morning, so it rained last night.

Induction: Where induction moves from the specific to the general. In induction, the conclusion "probably" follows the premises and is not necessarily true.

Examples of Inductive Logic: Every three year old you see at the park every afternoon

spends most of their time crying and screaming. Your conclusion is that all three year olds spend their afternoon screaming.

Every house that burned down on the block was caused by faulty wiring. You conclusion is that all homes on the block have faulty wiring.

INDUCTIVE REASONING

Inductive reasoning works the opposite way, moving from specific observations

to broader generalizations and theories. This is sometimes called a “bottom

up” approach. The researcher begins with specific observations and measures,

begins to then detect patterns and regularities, formulate some tentative hypotheses to explore, and finally ends up developing some general conclusions or theories.

Example: An example of inductive reasoning can be seen in this set of

statements: Today, I left for work at eight o’clock and I arrived on time. Therefore, every day that I leave the house at eight o’clock, I will arrive

to work on time.

DEDUCTIVE REASONING

Deductive reasoning happens when a researcher works from the more general

information to the more specific. Sometimes this is called the “top-down”

approach because the researcher starts at the top with a very broad spectrum

of information and they work their way down to a specific conclusion.

Example: Every day, I leave for work in my car at eight o’clock. Every day, the drive to work takes 45 minutes I arrive to work on time. Therefore, if I leave for work at eight o’clock today, I will be on time.

CONCLUSION

As these examples show, you can use logic to solve problems and to draw

conclusions. Sometimes those conclusions are correct conclusions

and

sometimes they are inaccurate. When you use deductive reasoning, you arrive

at correct logical arguments while inductive reasoning may or

may not provide you with a correct outcome.