COVERAGE LOGIC FINALS

KINDS OF CATEGORICAL PROPOSITION

1. Universal / Singular affirmative (A)

2. Universal/Singular negative (E)

3. Particular affirmative (1)

4. Particular negative (O)

FOUR KINDS OF LOGICAL OPPOSITION

1. Contradictory Opposition (CD)

2. Contrary Opposition (CT)

3. Subcontrary (SC)

4. Subaltern (SA)

ST. THOMAS AQUINAS

ST. AUGUSTINE

Socrates

PLATO

Confucius

Karl Marx

George Boole

Gottlob frege

Kurt godel

FOUR KINDS OF LOGICAL OPPOSITION

Contradictory Opposition (CD)

Contrary Opposition (CT)

Subcontrary (SC)

Subaltern (SA)

Example:

All criminal acts are punishable by law.

Some criminal acts are not punishable by law.

Contradictory Opposition (CD)

Example:

All winged animals are two-legged.

No winged animals are two-legged.

Contrary Opposition (CT)

Example:

Some killings are just

Some killings are not just.

Subcontrary (SC)

Example:

All corrupt officials are dishonest.

Some corrupt officials are dishonest.

Subaltern (SA)

LAWS OF LOGICAL OPPOSITION

Contradictory propositions/oppositions

Contrary propositions

Subcontrary propositions

Subaltern propositions

Example:

If "All men are mortal" is TRUE, then

"Some men are not mortals" is FALSE.

If "Some students are studious" is FALSE, then

"No students are studious" is TRUE.

Contradictory propositions/oppositions

Example:

If "No students are stupid" is true, then

"All students are stupid" is false.

If "All politicians are crooks" is false, then

"No politicians are crooks" is unknown or doubtful.

Contrary propositions

Example:

If "Some government officials are poor" is false, then

"Some government officials are not poor" is true.

But if "Some government officials are poor" is true, then "Some government officials are not poor" is unknown or doubtful.

Subcontrary propositions

UNIVERSAL IS TRUE

Example:

If "All cheaters are suspended" is true, then

"Some cheaters are suspended" is also true.

If "Some questions are difficult" is true, then

"All questions are difficult" is unknown or doubtful.

UNIVERSAL IS FALSE

Example:

If "Some ideas are significant" is false, then

"All ideas are significant" is also false.

But if "All killers are criminals" is false, then

"Some killers are criminals" is unknown.

Subaltern proposition

RULES AND FALLACIES OF CATEGORICAL SYLLOGISM

Fallacy Of Four Terms

Fallacy Of Equivocation

Fallacy Of Misplaced Middle Term

Fallacy Of Undistributed Middle Term

Fallacy Of Negative Premises

Fallacy Of Particular Premises

Fallacy Of Illicit Major Term

Fallacy Of Illicit Minor Term

Example:

All angels are saints.

But all angels are God's creatures.

Therefore, all God's creatures are saints.

Fallacy Of Illicit Minor Term

Example:

Some saints are martyrs.

But no sinners are saints.

Therefore, some sinners are not martyrs,

Fallacy Of Illicit Major Term

Example:

Some animals are carabao.

Some animals are black.

Therefore, some carabaos are black.

Fallacy Of Particular Premises

Example:

No Americans are Russians.

No German are Filipinos.

Therefore, no Americans are Filipinos.

Fallacy Of Negative Premises

Example:

Some students are working.

Some workers are exploited.

Therefore, some students are exploited.

Fallacy Of Undistributed Middle Term

Example:

All teachers are professional.

Pedro is a teacher.

Pedro is a teacher and a professional.

Fallacy Of Misplaced Middle Term

Example:

Light guides you in the dark.

Feathers are light.

Therefore, feathers guide you in the dark

Fallacy Of Equivocation

Example:

All Filipinos are Asians.

All Cebuanos are Visayans.

Therefore, all Cebuanos are Asians.

Fallacy Of Four Terms

GENERAL TO SPECIFIC

Example:

G - All OFWs are suffering from homesickness.

S - Pedro is an OFW.

Conclusion - Pedro is suffering from homesickness.

G - Every good act is rewarded.

S - Patience is a good act.

Conclusion - Patience is rewarded.

DEDUCTIVE REASONING

SPECIFIC TO GENERAL

Example:

S - Tigris is a river.

S - Euphrates is a river.

S - Nile is a river.

G - But, all rivers empty to the sea.

Conclusion - Therefore, the Tigris, Euphrates, and Nile rivers empty to the sea.

INDUCTIVE REASONING