8/9/2019 Logic Complete Assignment

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What is Proposition?Proposition is a statement which either asserts or denies something.

OrProposition is group of ideas of which anything is affirmed or denied

For ancient thinkers, proposition is the enunciation of truth or falsity.

Types of Proposition

Categorical: A categorical proposition unites or separates two concepts by means

of the linking verb to be.

Hypothetical: A hypothetical proposition unites or separates, not two concepts buttwo enunciations by means of a non-verb copula

Examples of Categorical Propositions

Some sharks are not dangerous.

Every kind act is meritorious.

Examples of Hypothetical Propositions

If it is a car, it has a motor.

If you are a Pakistani, then you are a native of Pakistan.

Every proposition has quality and quantity

Quality: the quality of a proposition maybe affirmative or negative

A proposition that has no or not is negative. This is oftentimes determined by the

copula

PROPERTIES OF PROPOSITIONS

Quantity: the quantity of a proposition is either universal or particular.

The proposition is universal when what is being affirmed or denied of the subjectterm is its whole extension and particular when what is being affirmed or denied

is just part of its extension.

THE FOUR CATEGORICALS

A stands for affirmative and universal propositions (All S is P)

Examples: All bachelors are unmarried men.

Every butterfly is an insect.

I stands for affirmative and particular propositions (Some S is P)

Ex. Some Indians are Moslems.

Some Peshawar University students are naughty.

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E stands for negative and universal propositions ( No S is P or All S is not P)

Examples: No speaker of Congress in the Philippines has become the president.

No bird has four legs.

Assam is not a Pakistan province.

0 stands for negative and particular propositions (Some S is not P or Not All S

is P) Examples: Some senators are not lawyers

Not every journalist gives accurate and well-founded report.

No one who died for his country died in vain.

Some students in this class are Pukhtoons.

Dr. Qadeer is a national hero.

Most congressmen are not giving up their pork barrel.

Three senators are running for the presidency.

No one is above the law.

The mantis is an insect.

Not every plant bears fruits.

An argument is a group of propositions in which one proposition is asserted to be

true on the basis of the other proposition

An argument is not categorized as true or false but as either logical or illogical,valid or invalid sound or unsound

RECOGNIZING ARGUMENTS

An argument is a group of propositions in which one proposition is asserted to betrue on the basis of the other proposition

An argument is not categorized as true or false but as either logical or illogical,

valid or invalid sound or unsound

ARGUMENTS

The proposition which is claimed to be true is called the conclusion while theproposition which serves as support of the conclusion is called premise.

Premise-indicators:

Some, because, for, given that, as indicated by, if

Conclusion-indicators

Therefore, thus, hence, so, accordingly, consequently

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PROPERTIES OF ARGUMENTS

TRUTH refers to the conformity of proposition to reality

LOGIC refers to the connection between the premises and the conclusion

SOUNDNESS property of argument as a whole

An argument maybe logical while one or more of its premises are false. For example:

All Panjabis are Asians.But yousaf Gillani is a panjabi.

Therefore, yousaf Gillani is Asian.

There are arguments whose premises are true but are not logical:

Cows have horns.Horses are not cows.

Therefore, horses have no horns.