Categorical Statements
No vampire movies are films without blood.
Quality: negative
Quantity: universal
Letter name: E
Distribution: S & P or "vampire movies" and "films without blood"
A carpenter's square is a square used by a carpenter.
What is Circular?
Convert proposition and state whether change is logically equivalent or not.
CONVERSE
All hurricanes are storms intensified by global warming.
All storms intensified by global warming are hurricanes.
NOT logically equivalent
Write in standard form and determine whether it is valid or invalid (if invalid state the broken rule).
AII-3
All M are P
Some M are S
Some S are P
VALID
Identify Mood & Figure of syllogism, then determine whether it is valid or invalid (if invalid tell which rule was broken)
Some nebulas are clouds of gas
Some clouds of gas are objects invisible to the naked eye
Some objects invisible to the naked eye are nebulas
Mood: III
Figure: 4
INVALID; rule 1
Some symphony orchestras are organizations on the brink of bankruptcy.
Quality: affirmative
Quantity: particular
Letter Name: I
Distributed: none
A cello is a stringed musical instrument played with a bow.
What is Too Broad?
Convert proposition and state whether change is logically equivalent or not.
OBVERSE
All radically egalitarian societies are societies that do not preserve individual liberties.
Write in standard form and determine whether it is valid or invalid (if invalid state the broken rule).
OEA-4
Some P are not M
No M are S
All S are P
INVALID; Rule 3
Identify Mood & Figure of syllogism, then determine whether it is valid or invalid (if invalid tell which rule was broken)
No endangered species are creatures loved by the timber industry
All spotted owls are endangered species
Some spotted owls are not creatures loved by the timber industry
Mood: EAO
Figure: 1
INVALID; rule 5
All human contacts with benzene are potential causes of cancer.
Quality: affirmative
Quantity: universal
Letter Name: A
Distribution: S or "human contacts with benzene"
A sculpture is a three-dimensional image made of marble.
What is Too Narrow?
Convert proposition and state whether change is logically equivalent or not.
CONTRAPOSITION
All physicians whose licenses have been revoked are physicians ineligible to practice.No physicians eligible to practice are physicians whose licenses have been revoked.
ARE logically equivalent
Write in standard form and determine whether it is valid or invalid (if invalid state the broken rule).
IAE-1
Some M are P
All S are M
No S are P
INVALID; Rule 2
Identify Mood & Figure of syllogism, then determine whether it is valid or invalid (if invalid tell which rule was broken).
No individuals sensitive to the difference between right and wrong are people who measure talent and success in terms of wealth
All corporate take-over experts are people who measure talent and success in terms of wealth
No corporate take-over experts are individuals sensitive to the difference between right and wrong
Mood: EAE
Figure: 2
INVALID; rule 1
Some hospitals are organizations that overcharge the Medicare program.
Quality: affirmative
Quantity: particular
Letter Name: I
Distribution: none
A theist is anyone who is not an atheist or an agnostic.
What is Negative?
Convert proposition and state whether change is logically equivalent or not.
OBVERSE
Some budgetary cutbacks are not actions fair to the poor.
Some budgetary cutbacks are non-actions fair to the poor.
ARE logically equivalent
Write in standard form and determine whether it is valid or invalid (if invalid state the broken rule).
EAO-4
No P are M
All M are S
Some S are not P
INVALID; rule 5
Identify Mood & Figure of syllogism, then determine whether it is valid or invalid (if invalid tell which rule was broken)
All members of the National Rifle Association are people opposed to gun control
All members of the National Rifle Association are law-abiding citizens
All law-abiding citizens are people opposed to gun control
Mood: AAA
Figure: 3
INVALID; rule 2
Some affirmative action plans are not programs that result in reverse discrimination.
Quality: negative
Quantity: particular
Letter Name: O
Distribution: P or "programs that result in reverse discrimination"
Puberty: the time in life in which the two sexes begin first to be acquainted.
What is Vague/Obscure/Figurative?
Convert proposition and state whether change is logically equivalent or not.
CONTRAPOSITION
Some opponents of gay marriage are not opponents of civil unions.
Some non-opponents of civil unions are not non-opponents of gay marriage.
ARE logically equivalent
Write in standard form and determine whether it is valid or invalid (if invalid state the broken rule).
IAO-2
Some P are M
All S are M
Some S are not P
INVALID; rule 1 & rule 2
Identify Mood & Figure of syllogism, then determine whether it is valid or invalid (if invalid tell which rule was broken)
All transparent metals are good conductors of heat
All transparent metals are good conductors of electricity
Some good conductors of electricity are good conductors of heat
Mood: AAI
Figure: 3
INVALID; rule 5